Article
Reference
Capillary Electrophoresis Instruments for Medical Applications and Falsified Drug Analysis/Quality Control in Developing Countries
TOBOLKINA, Elena, RUDAZ, Serge
Abstract
The implementation of integrated analytical techniques to meet stringent requirements in the life sciences requires a well-developed analytical capacity. New technology in analytical equipment for the analysis of large and small molecules is continuously being developed.
However, developing countries frequently struggle to keep pace with technological advancements. Hence, it is of utmost importance to better invest in optimizing existing and proven methodologies to tackle life-saving challenges in developing countries. In this regard, capillary electrophoresis is a promising candidate for solving multiple analytical problems compared to its chromatographic and spectroscopic counterparts due to its fast analytical response time and notable cost efficiency. In the following, we summarize various issues and opportunities for capillary electrophoresis to be the technique of choice for the unresolved bottlenecks in analytical equipment in developing countries for drug quality control. This perspective demonstrates that the ongoing quest for the design of new, impactful analytical techniques is a dynamic and rapidly developing [...]
TOBOLKINA, Elena, RUDAZ, Serge. Capillary Electrophoresis Instruments for Medical Applications and Falsified Drug Analysis/Quality Control in Developing Countries. Analytical chemistry , 2021, vol. 93, no. 23, p. 8107-8115
DOI : 10.1021/acs.analchem.1c00839 PMID : 34061489
Available at:
http://archive-ouverte.unige.ch/unige:155152
Disclaimer: layout of this document may differ from the published version.
1 / 1
Capillary Electrophoresis Instruments for Medical Applications and Falsi fi ed Drug Analysis/Quality Control in Developing Countries
Elena Tobolkina and Serge Rudaz*
Cite This:Anal. Chem.2021, 93, 8107−8115 Read Online
ACCESS
Metrics & More Article RecommendationsABSTRACT: The implementation of integrated analytical techniques to meet stringent requirements in the life sciences requires a well-developed analytical capacity. New technology in analytical equipment for the analysis of large and small molecules is continuously being developed. However, developing countries frequently struggle to keep pace with technological advancements. Hence, it is of utmost importance to better invest in optimizing existing and proven methodologies to tackle life-saving challenges in developing countries. In this regard, capillary electrophoresis is a promising candidate for solving multiple analytical problems compared to its chromatographic and spectroscopic counterparts due to its fast analytical response time and notable cost efficiency. In the following, we summarize various issues and opportunities for capillary electrophoresis to
be the technique of choice for the unresolved bottlenecks in analytical equipment in developing countries for drug quality control.
This perspective demonstrates that the ongoing quest for the design of new, impactful analytical techniques is a dynamic and rapidly developing research area and mentions some directions and opportunities that have arisen during the recent pandemic.
U
ndoubtedly, the development of modern society has been achieved through continuous human progress and its inextricable link to scientific research. However, distinct scientific inequalities have led developing countries, facing difficulties with healthcare provision and quality control, not to take functioning scientific equipment for granted. Scientific research endeavors and quality control analysis in developing countries are barely possible due to laboratory limitations coupled with restricted funding availability for the purchase, service, operation, and maintenance of scientific equipment.1 Equally important is that a modern quality control laboratory can only operate with the involvement of highly educated and well-trained technicians and human resources. Another key problem is that instrument performance is dependent on environmental conditions.2 Most analytical equipment is manufactured for specific environmental surroundings and is not designed to withstand hostile weather. Furthermore, access to stable air conditioning, electricity, gas lines, water supply, purification systems, andfilters as well as an adequate internet connection play a vital role.3 Hence, the current need for a versatile analytical technique that overcomes all the above challenges is more important than ever.Typically, a wide variety of analytical techniques for the quantitative analysis but also for the quality control (QC) analysis of large and/or small molecules are applied.4 For example, thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), and gas chromatography (GC) are well-established techniques. In addition, a broad
variety of spectroscopic techniques such as infrared (IR), near- infrared (NIR), Raman spectroscopy, nuclear magnetic resonance (NMR), and mass spectrometry (MS) have received increased attention in recent years.5−7 Notwithstanding the reliable analysis of relevant compounds using chromatographic and spectroscopic techniques, there is an inherent need to mitigate all the aforementioned constraints. Since its introduction, capillary electrophoresis (CE) has become a cost-efficient and versatile analytical tool.8 To date, CE is a mature and well-established analytical technique that is known for numerous applications including high-resolution DNA sequencing.9,10 CE has established its credentials, playing an essential role in contemporary biopharmaceuticals and, more recently, in the QC of therapeutic proteins.11 Current applications of CE lie in the analysis of small inorganic ions, low molecular weight, and chiral analysis of large biomole- cules.12,13
Because we believe that CE could be an alternative versatile analytical tool for application in developing countries, this perspective does not intend to be exhaustive but rather aims to
Received: February 24, 2021 Accepted: May 17, 2021 Published: June 1, 2021
© 2021 The Authors. Published by
Downloaded via UNIV OF GENEVA on September 21, 2021 at 15:48:17 (UTC). See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles.
be a condensed update on some advancements, opportunities, strengths, and pitfalls in the present context. Selected articles are summarized in the following section and are rounded off with a brief discussion of the unresolved bottlenecks in this research area. The following discussion will mainly rely on cost-affordable and open-source capillary electrophoresis for medical determinations, focusing on falsified and substandard drug analysis, in which CE has already demonstrated great potential that is, unfortunately, not yet confirmed by wider use in developing countries.
■
ANALYTICAL TECHNIQUES SUITABLE FOR USE IN DEVELOPING COUNTRIESThe rise of clandestine trade in substandard and falsified (SF) medical products is a major threat to public health. By definition, falsified medicines are medical products “that deliberately/fraudulently misrepresent their identity, composi- tion or source”,14while substandard drugs refer to authorized products that “fail to meet either their quality standards or specifications, or both”.15The detection of SF, namely, those with incorrect, inactive ingredients or with incorrect amounts of active ingredients, is among the main challenges of developing countries.16 The QC of medicines is essential to avoid adverse effects induced by SF drugs, which covers nearly 10% of all the pharmaceutical markets of low- and middle- income countries.14Therefore, the evaluation of the quality of active pharmaceutical ingredients (APIs) is one of the fundamental tasks in contemporary quality control and good manufacturing practices (GMPs) in all laboratories. To this end, numerous and various analytical techniques (i.e., mainly spectroscopic and separation approaches) are used for the quantitative, purity, and elemental analysis of API as well as the other components of a drug formulation. All these techniques can also be evaluated regarding the importance of the needed equipment, training, and sample preparation complexity that remains mandatory for most of them.
It should be noted that medicines that fail quality standards and are thus considered“substandards”can be legitimate (“out of specification”) or illegitimate, while unapproved medicines, considered “falsified”, can meet or not meet in any case the quality specifications (Figure 1).17 The first question to be asked is whether it is necessary to prioritize techniques to differentiate between registered and falsified products or to determine whether all products are of sufficient quality and therefore safe for the patient. Since many more antibiotic, antiparasitic, and antiretroviral medicines are needed, we believe that the expansion of the frequent use of SF drugs in
developed and developing countries is mainly associated with challenges in QC, especially with the possibility of rapidly assessing the presence and appropriate quantity of the API in the suspected drug product, regardless of its production source.
Such determination is another important aspect of medicines related to trust in drugs by the patients themselves.
In less resourced countries, the comprehensive QC of circulating drug products is difficult due to relatively restricted laboratory capacities and relatively weak analytical infra- structures, and a sequential approach is recommended. The American and European pharmacopoeias as well as the WHO have defined the strategies and analytical procedures required to control drug quality.14,15Thefirst step should consist of the visual evaluation of the primary (in direct contact with the medicine, e.g., blister pack) and secondary (e.g., cardboard box) packaging of the product. Evaluation of the packaging based on a comparison with the genuine sample and/or search for manipulation signs assisted by mobile devices is valuable.
The second step will require competence in analytical procedures that allow qualitative and/or quantitative analysis to identify and measure the drug. Typically, this step should start with onsite screening using rapid tools to verify whether the global quality of the suspected drugs meets the expected requirements. Such an approach must be nondestructive, simple, quick, and use hand-held devices intended for onsite use. As a result, the possibility of obtaining initial information through spectroscopic methods is highly recommended.18
Robust, effective, and precise protocols for the evaluation of a drug product can be performed with numerous spectroscopic techniques, such as Fourier transform-infrared (FT-IR), NIR,19,20 Raman spectroscopy,21 and low-resolution NMR.22 The latter has been preferred to NIR due to a possible comparison with a compound spectral database23 but is probably much more costly. Spectroscopic techniques can analyze both solid and liquid formulations, leaving the samples almost undamaged, which can then be further used for tests by other analytical techniques. Spectroscopic techniques are generally fast and less complex to handle than the separation approach. However, three main issues affect the development of these spectroscopic approaches in the field. First, a comparison with databases containing reference spectra is mandatory to obtain results. In addition to considering the possibility of having such a spectrum library available locally, the first issue is the construction of these databases, which must contain numerous reference spectra to be efficient. It is therefore necessary to have at disposal a large number of certified samples corresponding to the suspected product. Such capacity is difficult without collaboration with manufacturers and is not realistic in the context of falsified medicine. The second issue concerns the high volatility of the drug supply chain and the numerous drug formulations existing for a single drug dosage. Analysis of several tablets per sample and some colored or degraded formulations is difficult,21and the concept of reference products is often not applicable. The last point represents the most critical issues. Spectroscopic techniques are diverse in their performance, and when the absolute quantification of APIs is impractical or the obtained information cannot directly rely on the API but on the global composition of the drug products, spectroscopy could constitute only a screening approach that helps avoid false appreciation leading to an erroneous sense of security.
After screening as many samples as possible, although false- positive results may be obtained because of the relatively low Figure 1.Categories of legitimate and illegitimate medicine.
Analytical Chemistry pubs.acs.org/ac Perspective
https://doi.org/10.1021/acs.analchem.1c00839 Anal. Chem.2021, 93, 8107−8115 8108
specificity of such assays regarding the API, which thus circumvent the determination of structurally similar molecules, such as impurities, the samples that require further investigation should be analyzed with a separation method and in a well-equipped quality control laboratory with trained staff. Undoubtedly, to truly estimate if a sample complies in terms of quality or appropriate API quantity, confirmatory analysis should be achieved by separation techniques. The latter are able to detect small differences in the samples and are mandatory for reliable discrimination between genuine and falsified and/or substandard samples. Hence, bringing in high- quality separation analysis to fight major health and public safety issues at an affordable cost is a challenge. Considering the limited technical and financial resources in most developing countries, initiatives have emerged to provide sustainable and affordable analytical instrumentation that can be easily implemented at a low cost by official laboratories and/or not-for-profit organizations within these countries.
This ongoing effort for the development of highly efficient and inexpensive separation techniques remains the key point for the detection of SF drug quality control. Notwithstanding the recent advances in thefield, the fundamental improvement and optimization of existing and proven technologies need to be further addressed. Focusing efforts on the development of analytical tools that require fewer chemicals and reagents is essential, considering the expensive solvents and chemicals along with the consumables needed. These efforts need to be coupled with higher instrument sensitivity and accuracy.
Relatively low detection limits should be available when considering the analysis of impurities as a part of the QC of a drug formulation. As is known from the literature, precision and accuracy are strongly dependent on the manufacturer- recommended environmental conditions and continuous power supply.24Thus, unpredictable weather conditions such as elevated temperatures, air humidity, and power outages as well as supply shortages of consumables in many developing countries all constitute an increased need for versatile and robust analytical devices and techniques. That the pharma- ceutical market worldwide operates under strict regulatory frameworks with highly controlled standards as well as highly laboratory standards, as introduced by the WHO, represents an important unresolved bottleneck in the field from a non- scientific standpoint;25to be concrete, only a few laboratories in developing countries are able to meet international quality and laboratory standards.
Thin-layer chromatography (TLC) is considered one of the most widely used techniques for the semiquantitative and quantitative analysis of APIs in major pharmacopoeias.26 Despite its important role, the relative amount of organic solvent needed for this process is one of its main drawbacks.
Some TLC methods are well-known and can be found in the global pharma health fund GPHF-Minilab, which contains essential labware, chemicals, and a wide range of control substances for benchmark purposes.27 Some methods can be performed manually, but the accuracy and reproducibility of such experiments will strongly depend on the experience and skills of the researcher. More recently, TLC was replaced by high-performance thin-layer chromatography (HPTLC), where the reproducibility and accuracy of the quality control of APIs as well as the resolution of compounds are significantly increased. Recent findings in the literature have shown that HPTLC can quantitatively determine a variety of APIs at the same time, but the expensive and special chromatographic
plates required for such analyses prohibit their larger use in developing countries.28 HPLC remains the gold standard for drug quality control owing to its better reproducibility, accuracy, and sensitivity regarding the detection of all APIs.29 Because HPLC is often recognized as the official method of different pharmacopoeias, it represents the analytical benchmark with the highest worldwide relevance.
The use and maintenance of such scientific equipment is highly challenging in developing countries due to infrastructural conditions and carries considerable difficulties related to regular maintenance due to the regular use of high-pressure and therefore mechanical constraints. CE can be a promising alternative to current chromatographic and spectroscopic techniques combining all these characteristics, as analytical techniques require the mitigation of the crucial problems associated with the availability of a separation technique in many laboratories.30 In this context, and as a complement to other official analytical methods, CE could be the most appropriate economical and eco-friendly technique.31
■
LOW-COST CAPILLARY ELECTROPHORESIS, APPROPRIATE TECHNOLOGY, AND OPEN SOURCEJorgenson and Lucas first introduced modern CE in 1981,32 and since then, it has been widely recognized as a powerful, efficient, and resolutive separation technique in the analytical field.11 Electrophoresis is founded on the displacement of charged species (ions) in an electric field. CE is used to separate analytes in fused silica capillariesfilled with electrolyte solution according to charge and size.1After thefirst decade of development studies and instrument commercialization, CE has gone through a period of rapid growth. The CE technique is frequently used since it presents several important advantages, such as high efficiency, short analysis time, small volume of samples injected, cost efficiency, simplicity, and diversity of applicationfields.33The versatility of CE is partially derived from its numerous modes of separation. Different electrophoresis modes provide the diversity of CE analyses by considering the physicochemical properties of the compounds of interest and can offer orthogonal information. CE is considered a strong separation technique that is applied in various research applications, such as quantitative or kinetic analysis of inorganic compounds,34,35 proteins,36,37 pepti- des,38,39amino acids,40chiral drugs,41,42metabolites,43organic acids,44−46carbohydrates,47 vitamins,48 body fluid samples,49 and viruses and bacteria.50,51 In most developing countries, laboratories are often restricted by the high value of brand- name scientific equipment, which slows down scientific development, a concern that remains valid for CE. However, the concept of low cost cannot always be considered an ideal solution. One should be aware that the perception of the authorities or laboratory members concerned is that a low-cost device can be manufactured at a reduced price due to the lower quality of its components. This concern can lead to the belief that the analyses carried out using such devices will be of inferior quality, a point that has been discussed many times during our various stays in Africa to promote CE for drug quality control. The concept of “appropriate technology” or
“intermediate technology”, which focuses on pragmatic approaches that could be more efficient than the“unproduc- tive”technologies of industrialized societies, must be preferred.
Appropriate hard technology is defined as “engineering techniques, physical structures, and machinery that meet a
need defined by a community and utilize the material at hand or readily available. It can be built, operated, and maintained by the local people with very limited outside assistance (e.g., technical, material, orfinancial)”.52In addition to its common relationship to an economic goal, CE, particularly capillary zone electrophoresis (CZE), is the only separation approach with high efficiency that can be used with a relatively simple level of technology. CE fulfills all the features used in developed countries to indicate “appropriate and sustainable technology”. Open-source hardware (OSH) for laboratory equipment is the second prerequisite to afford a significant impact and promote its use through laboratories. OSH probably represents the best strategy for implementing prototypical instruments in developing countries and allows the successful training of local personnel to accomplish the task of reliable identification and quantification of pharmaceuticals.
In a very recent review, Kuban et al. have provided the most up-to-date information on open-source hardware and software resources enabling the construction and utilization of an“open source” CE instrument.53 As stated by the authors, the open philosophy facilitates the dissemination of science within and outside the scientific community, fosters innovation, and allows the constant improvement of shared blueprints. By collecting extensive information on open-source CE, the authors have clearly facilitated the possibility of disseminating knowledge on CE within and outside the scientific community and innovation. Other initiatives have also demonstrated that, despite being inexpensive to build, a functional open-source CE system with good performance can be built. Furthermore, owing to the open-source philosophy, users (including junior and/or senior scientists) could appropriate the machine, understand it, and be able to repair it. Some normal-wear parts will always remain difficult to obtain in developing countries; therefore, it is necessary to rethink the design of the CE so that each component can be replaced with a local solution or is easily available via the internet. As an example, Furter et al. developed a cost-saving automated capillary electrophoresis analytical instrument assembled with commer- cially available parts.54The latter can be easily duplicated and consist of an electropneumatic part, a data acquisition system, afluid handling part, an electronic controller, a safety cage with an HV electrode, an HV module, and a commercially available
C4D detector. The development of an electronic interface circuitry is needed and cannot be opted out of, as the authors pointed out. The total cost of the instrument is approximately
€6500, of which more than half is attributed to the contactless conductivity detector. To further reduce the cost, a non- regulated high-voltage module without monitoring functions can be employed, and the detector can be manufactured in- house, as reported in the following articles.55−58
The fact that additive manufacturing (3D printing) is becoming widely available, allowing anyone to manufacture highly complex objects at very low cost, represents another opportunity for CE.59,603D printing is increasingly present not only in industry and research facilities but also in many households. The production cost of 3D printed objects is extremely low; additive manufacturing is particularly suitable to design prototypes or in niche markets where expected sales do not justify large-scale manufacturing. Moreover, the cost- effective and“fun”factors of 3D printing favor the emergence of a community of “makers” who develop new objects using 3D printing with an open-source philosophy. In the context of the collaboration among the University of Geneva (Switzer- land), the University of Applied Sciences of Fribourg (Western Switzerland), and Geneva University Hospitals (Switzerland), an open-source device to help developing countries control the quality of medicines was proposed (Figure 2).61This proposal allowed the launch of a new-generation CE device for which welding and assembly costs represented less than 40% of the cost of the device, while 60% was previously used. 3D printing and laser-cutting technologies have allowed the inexpensive production of parts with equivalent precision and mechanical strength. For this new version of the open-source CE, other attractive technical solutions have been proposed. The 12 VDC primary power supply will be provided either by the conventional 230/110 VAC 50/60 Hz mains via an AC/DC transformer when used in the laboratory or by a car battery (e.g., cigarette lighter socket) when used in the field. In the case of power failure, an uninterruptible power supply (UPS) system based on a lithium battery will provide at least 3 h of autonomy. For more autonomy, a secondary power supply will be possible owing to an external photovoltaic panel.
Figure 2.Low-cost capillary electrophoresis evolution proposed by the University of Applied Sciences of Fribourg (Switzerland).
Analytical Chemistry pubs.acs.org/ac Perspective
https://doi.org/10.1021/acs.analchem.1c00839 Anal. Chem.2021, 93, 8107−8115 8110
■
PORTABLE CE FOR APPLICATION IN DEVELOPING COUNTRIESIn addition to the fact that compactness of CE is not provided by the main suppliers, this technique can also present great potential for use in point-of-care diagnostics. Numerous articles to date have reported the advantages of the miniaturization of fluidic systems in various environments.
Portable CE could push forward applications in developing countries to a larger extent than the context of falsified and substandard drugs. The most commonly reported advantages of portable CE are onsite analysis, cost efficiency, disposability, reduced required sample volumes for the analysis, more rapid analysis response, the generation of large electric fields in a more efficient and simplistic way, and independence from the country’s electrical grid.62
Portable CE has attracted considerable attention in recent years because of its mode variations and method variations.
There are a number of modes of operation, such as capillary gel electrophoresis (CGE), capillary isoelectric focusing, micellar electrokinetic capillary chromatography (MEKC), capillary (electrochromatography), and isotachophoresis.63 However, the vast majority of literature refers to CZE since the other methods are not simple to use.64Even though the miniaturization of CE offers numerous advantages, some design considerations and challenges for miniaturized CE systems need to be considered for wider implementation.
Some criteria that need to be met are the device size, the quality and robustness of the materials, the fabrication method, the separation efficiency, the overall analysis time, the total operation lifetime, and the minimum user intervention required.65 To provide a more precise metric by which a portable CE system will be considered successful, the following requirements must be met. Ideally, the size should fit in the
palm of a hand, the weight should be less than a few kilograms, chargeable and/or changeable batteries should be used for daily use and for in situ monitoring modes, and a long lifetime on the order of weeks would be preferable. Equally significant is the lifetime of the device, which means that the quality of the materials chosen needs to be reliable and able to resist contamination and similar problems.66 Moreover, the level of device autonomicity (sample loading, operation, analysis, and cleaning) is highly important as well, as is the fast analysis response performed on a microchip and the display of the outcome on the device’s screen.
Pan et al., for example, proposed the smallest-to-date miniaturized palmtop high-speed capillary electrophoresis with laser-induced fluorescence (LIF) detection for bioanal- ysis.67The total dimensions of this device were reported to be 90 mm × 75 mm × 77 mm. The simple and low-cost components of this device led to an extremely reduced instrument cost (i.e., $500). In its analytical performance, the device reached a limit of detection of 1.02 nM sodium fluorescein. Multiple samples were tested, such as amino acids, amino acid enantiomers, DNA fragments, and high-efficiency proteins, and the devices were employed for the colorectal cancer diagnosis of KRAS mutations. QC control methods should be transferred to this kind of device to evaluate their performance in the context of drugs, and it is regrettable that so few academic groups promote the use of this kind of instrumentation for educational purposes.
The portable format will require a number of compromises and considerations from scientists and, subsequently, from manufacturing companies. More precisely, from the device standpoint, a chip or nonchip choice, the material choice and capillary shape as well as device dimensions are some of the main challenges. Second, because CE separation could be Figure 3. (A) Image of the fully integrated palmtop CE bioanalyzer (adapted from ref67), (B) image of the portable CE instrument with contactless conductivity detection. Reproduced with permission from ref65. Copyright 2016 Elsevier. (C) Automated capillary electrophoresis system with electrochemical detection (CE-ECD). Reproduced with permission from ref81. Copyright 2010 Elsevier. (D) Low-cost automated CE instrument assembled from commercially available parts. Reproduced with permission from ref54. Copyright 2020 John Wiley and Sons.
affected by the absence of temperature control more significantly than other analytical techniques, appropriate methodological steps should be envisaged to ensure the quality of the results. As an example, the multiple injection approach offered an alternative way to compensate for temperature variability. In the same run, a standard of the tested drugs at a known concentration is first injected (“STD”), followed by an injection of the sample to be quantified (“unknown”). This procedure allows the decrease of the run-to-run variability (including identified as a major contributor of dispersion in the results).68 Finally, very low detection limits (i.e., impurity determination) and fast analysis responses with minimum sample volume are among the areas for further improvements. Even though there has been a strong interest and technological push in portable CE systems with a variety of successful devices in the past 5−10 years,69battery- powered CE systems with numerous operation modes need to be continuously improved in the CE research community and can reduce operational costs (Figure 3).
“Flying micro-lab”or CE separation on a drone proposed by Tomas Drevinskas et al.70 is another smart example of technological progress that can be used in hazardous remote places. The instrument that is less than 800 g is capable of collecting, determining, and quantifying the volatile and nonvolatile compounds from the air (Figure 4). The analytical data is transmitted wireless.
■
SOFTWARE AND SIMULATION APPROACHES In this section, we highlight the impact on a laboratory operations level and elaborate on the impact of the recent pandemic from the perspective of capillary electrophoresis as the technique of choice in developing countries. An integral part of analytical instruments is software for data acquisition, data processing, and statistical assessments, which remain a grueling and time-consuming process. To ensure acceptance of the device, it is necessary to adapt the interface according to the user’s level of training. The interface must be simple,intuitive, and multilingual and must guide the user through the analysis process. In most cases, the instrumentation is controlled by an external computer, but integration of a touchscreen could reduce the costs and improve the portability of the device. Even connection to a computer should remain possible for more complex data processing or if the laboratory wishes to use commercial analysis software. At the level of the control electronics and interface, Open Hardware products such as Arduino71or Raspberry PI72offer a high-performance solution that is inexpensive and available in Africa, for example.
The global health COVID-19 pandemic revealed numerous vulnerabilities and challenges faced by humanity; however, opportunities also arose. Many educational institutes and companies have already migrated to digitalfields, and many of them have already launched analytics and artificial intelligence (AI) initiatives in their operations. IT department teams have already delivered at a pace they never have before. New players are continually emerging in the context of data acquisition and treatment, and we hope in the near future to see more initiatives related to data processing, simulation in CE to facilitate the educational aspects and therefore the use of CE.
Dubsky et al. suggested the CEval software for fast, simple electrophoresis evaluation and data processing in affinity capillary electrophoresis (ACE).73 Common challenges, such as the electromigration time from the upper peak point of the electrophoregram, the linearization of the data, and the neglect of the viscosity of the analyte and other effects, are addressed by CEval software. Another example of software used in capillary zone electrophoresis comes from Bohuslav Gas at Charles University.74Their software, called PeakMaster, is an in-house program that amplifies the detector sensitivity and resolution sufficiency of analytes by optimizing and predicting the parameters of background electrolytes and analyte peaks.
The same group has introduced another free software, Simul,75 that reproduces the movement of ions in liquid solutions in an electric field. Other free software related to “electrophoresis” could be found on the GitHub76 repository Web site.
Concerning the pandemic crisis, remote work is compulsory;
therefore, access to laboratory facilities is limited. The aforementioned software can easily be used for data processing and separations predictions, paving the way for simulation experiments before real experiments start, which can save a considerable amount of laboratory time and, for example, wasted capital on chemicals and instrumental maintenance.
Moreover, in-silico approaches may aid the teaching aspects owing to case studies specially designed for understanding and adoption of the technique.
Last but not least, many educational organizations and the majority of companies have shifted to remote-working models almost overnight. Remote setups will allow organizations to mobilize global expertise instantly and respond to new technological needs and the development of new analytical capacities. Indeed, the ongoing quest for the design of new impactful analytical techniques and agility can be executed remotely.
■
COMMUNITY OF USERSTechnological learning and innovation are essential for the generation of new knowledge that can be applied to amplify productive and dynamic activity. However, such progress is strongly dependent on the ability to access, adapt, and implement such knowledge. For this reason, the transmission and implementation of standardized, clear, easily applicable Figure 4. Schematic diagram of the designed system: (a and b)
photograph of the CE system on a drone. Representation of sampling interface (c) and electropherogram of a blank sample (d).
Reproduced with permission from ref 70. Copyright 2021 Royal Society of Chemistry.
Analytical Chemistry pubs.acs.org/ac Perspective
https://doi.org/10.1021/acs.analchem.1c00839 Anal. Chem.2021, 93, 8107−8115 8112
protocols and methods for drug detection and quantification remain challenging in developing countries. Improving the quality of education, service, internet penetration, easily consulted or used disposal-dedicated web sites, web tutorials, and repositories will help to disseminate and share knowledge with the scientific community more effectively.
Networking-based research needs to achieve the proposed objectives and a supportive structure to integrate the efforts of groups that could be interested in advancing open-source CE.
This achievement will require combined efforts made by different groups, as the objectives are beyond the possible research of a single group. Hence, interaction and collaboration are the last but not least important points that should be addressed to support CE in various laboratories as well as in education through the engagement of students in creative, multidisciplinary projects about the use of CE for quality control.77 As an example, Sarr et al.78 implemented an affordable CE device at the Senegalese National Medicines Control Laboratory, where a CE method was developed and validated for quality assessment by Master’s students (University Cheick Anta Diop). This development became possible due to a collaboration between Swiss academic institutions and hospitals to help developing countries with limited means to combat falsified and substandard medicines.
Metronidazole samples were purchased from various markets in Benin and Senegal and analyzed by CE−LED/UV.
Fortunately, all collected samples were compliant with USP specifications and confirmed by an official chromatographic method described in the U.S. Pharmacopoeia. Similar results for both methods with comparable precision were obtained, demonstrating that CE analysis could be a real alternative.
The majority of these collaborative projects between the developing and developed countries enable the better develop- ment of healthcare professionals, especially among young researchers and students. All of them are dedicated tofinding the most suitable approaches and analytical methods for the analysis of various drug, water, environmental, or falsified samples. Most of the time, the number of such samples or batches for analysis is limited, and the use of a proper method of quantification is essential. CE together with the method of standard addition (SAM) would be a technique of choice, as a very low sample volume for analysis and no validation standard elaboration is needed. The last aspect is crucial since there is a large potential difference in drug product composition. Hence, the lack of an exact formulation leads to difficulties in API quantification through external calibration methodology because the reconstitution of representative samples remains impossible in the case of falsified or substandard medicine. The use of SAM will help to overcome the risks of inaccuracy from the unknown matrix by providing rapid quantification and determination of samples. As demonstrated for the quality control of antiretroviral drugs, when several detection wavelengths are available, the use of the H-point SAM, an improvement of SAM, helps to reduce both proportional and constant errors (Figure 5).79 These improvements could be attained simultaneously, allowing different determinations for a lower uncertainty.
Given access to analytical instrumentation in various associations, professionals, or nonprofit organizations from different universities will contribute to the consolidation of techniques and practices to improve health services in urban or rural areas, often far from first-aid clinics. Open-source CE should not be restricted to academic or national laboratories
because in numerous developing countries, public-private cooperation among ministries of health, local, and/or foreign pharmaceutical companies and their foundations are the only way to support vulnerable and often isolated populations.
Finally, new initiatives are mandatory to aggregate a dynamic and creative community of makers who are passionate about collaborative and open projects. The recently funded PortASAP COST Action aims to promote portable, affordable, and simple analytical platforms in a network of more than 16 countries with a good representation of the European research landscape.80By sharing construction plans and software source code, everyone can participate in the development of the device or adapt it to their needs. This collaborative development makes it possible to mobilize knowledge from all types of actors from an academic, associative, public, or entrepreneurial environment.
■
CONCLUDING REMARKS AND PERSPECTIVES A well-developed analytical capacity to tackle life-saving challenges in developing countries goes hand-in-hand with technological advancements and scientific research, which is the foundation of human growth and a nation’s growth.However, developing countries struggle to follow up with such advancements due to a number of scientific discrepancies between Western and developing countries. Keeping the present situation in mind, this perspective article presents a number of elements for considering CE as a technique suitable for developing countries and as a favorable candidate to include new research directions for the future. CE possesses numerous advantages compared to its counterparts and is open source (portable or not). CE systems offer a cost-affordable versatile separation tool; they require limited consumption of chemicals, and they have low power supply requirements, Figure 5.(A) Electropherogram of Truvada obtained with CZE: TD corresponds to tenofovir disproxil; FTC, emtricitabine. (B) H-point standard addition method applied to tenofovir disoproxil at three different wavelengths at 200, 210, and 254 nm. Reproduced with permission from ref79. Copyright 2020 John Wiley and Sons.
which further make them a sustainably economical solution.
CE also requires cost-friendly high-pressure components, has relatively very low detection limits and is at least sufficient to tackle the important issue of falsified and substandard quality control.
It is borne in mind that CE is, by nature, a miniaturized approach that is easily adjustable in a compact format. The quest for truly cost-friendly analytical equipment with life- saving impact in developing countries is more important than ever and can be resolved if chronic key problems are mitigated in addition to the ongoing technological advancements in analytical equipment. Mitigation measures include funding, climate, and power supply issues, workshops and training programs for technicians and researchers, as well as the development of databases for efficient management and information sharing. An action-oriented plan is essential from a higher level with the involvement of a variety of shareholders and country leaders to work on strategic policies, guidelines, and frameworks, which can be developed at institutional, regional, and national levels in developing countries. Block- chain databases, when combined and fully integrated with analytical approaches, offer an additional tool to strengthen the trust and monitoring quality in drug distribution chains and should be investigated further.
In addition to continuous improvements of the methodo- logical and technical aspects of the analytical device, online educational curriculum should also be developed and implemented (for example, with e-learning tools) to provide adequate initial and continuing as well as sustainable and readily deliverable training. Finally, although not directly related to the use of CE, academic players should support more intensive citizen science projects that collect information on medicines with devices that can be used by anyone (such as the use of smartphones to take pictures, geolocalize products, and create and curate databases). This approach is particularly attractive and complementary to chemical analysis because it involves all the layers of the population in the constant battle against falsified and substandard medicines.
■
AUTHOR INFORMATION Corresponding AuthorSerge Rudaz−Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, CH-1211 Geneva, Switzerland; orcid.org/0000-0002-4180-5417;
Phone: +41 22 37 96572; Email:[email protected] Author
Elena Tobolkina−Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, CH-1211 Geneva, Switzerland
Complete contact information is available at:
https://pubs.acs.org/10.1021/acs.analchem.1c00839
Notes
The authors declare no competingfinancial interest.
This perspective expresses only the authors’ views on the possibility of using CE instrumentation for medical applica- tions and falsified drug analysis/quality control in developing countries.
■
ACKNOWLEDGMENTSWe thank Víctor González-Ruiz for the help in elaborating the graphical abstract content.
■
(1) Hollein, L.; Kaale, E.; Mwalwisi, Y. H.; Schulze, M. H.;REFERENCES Holzgrabe, U.TrAC, Trends Anal. Chem.2016,76, 60−70.(2) Cervellini, A.; Vose, P. B.IAEA Bull.1983,25(2), 37−40.
(3) Solomon, T.; Åkerblom, M.; Thulstrup, E. W.Anal. Chem.2003, 75, 106 A−113 A.
(4) Martino, R.; Malet-Martino, M.; Gilard, V.; Balayssac, S.Anal.
Bioanal. Chem.2010,398, 77−92.
(5) Holzgrabe, U.; Malet-Martino, M.J. Pharm. Biomed. Anal.2011, 55(4), 679−87.
(6) Martino, R.; Malet-Martino, M.; Gilard, V.; Balayssac, S.Anal.
Bioanal. Chem.2010,398, 77−92.
(7) Deconinck, E.; Sacre, P.-Y.; Courselle, P.; De Beer, J. O. J.
Chromatogr. Sci.2013,51, 791−806.
(8) Le, T. B.; Hauser, P. C.; Pham, T. N.; Kieu, T. L.; Le, T. P.; Le, T. P.; Hoang, Q. A.; Le, D. C.; Nguyen, T. A.; Mai, T. C.
Electrophoresis2020,41, 1980−1990.
(9) Tohala, L.; Oukacine, F.; Ravelet, C.; Peyrin, E.Electrophoresis 2017,38, 1383−1390.
(10) Kanoatov, M.; Krylov, S. N.Anal. Chem.2016,88, 7421−7428.
(11) Voeten, R. L. C.; Ventouri, I. K.; Haselberg, R.; Somsen, G. W.
Anal. Chem.2018,90, 1464−1481.
(12) Vortmann-Westhoven, B.; Lurenbaum, C.; Winter, M.; Nowak, S.Electrophoresis2017,38, 540−546.
(13) Bernardo-Bermejo, S.; Sanchez-Lopez, E.; Castro-Puyana, M.;
Marina, M. L.TrAC, Trends Anal. Chem.2020,124, 115807.
(14) World Health Organization. Definitions of Substandard and Falsified (SF) Medical Products. https://www.who.int/medicines/
regulation/ssffc/definitions/en/(accessed 2020-02-09).
(15) WHO. Global Surveillance and Monitoring System for substandard and falsified medical products. https://www.who.int/
medicines/regulation/ssffc/publications/gsms-report-sf/en/ (ac- cessed 2021-02-03).
(16) Rahmat, S.; Cheong, C. B.; Hamid, M. S.Social and Behavioral Sciences2016,224, 445−451.
(17) Attaran, A.; Barry, D.; Basheer, S.; Bate, R.; Benton, D.;
Chauvin, J.; Garrett, L.; Kickbusch, I.; Kohler, J. C.; Midha, K.;
Newton, P. N.; Nishtar, S.; Orhii, P.; McKee, M.BMJ2012, 345, e7381.
(18) Wilson, B. K.; Kaur, H.; Allan, E. L.; Lozama, A.; Bell, D.Am. J.
Trop. Med. Hyg.2017,96(5), 1117−1123.
(19) Scafi, S. H.; Pasquini, C.Analyst2001,126, 2218−2224.
(20) Dégardin, K.; Guillemain, A.; Guerreiro, N. V.; Roggo, Y.J.
Pharm. Biomed. Anal.2016,128, 89−97.
(21) Ciza, P. H.; Sacré, P.-Y.; Waffo, C.; Coïc, L.; Avohou, H.;
Mbinze, J. K.; Ngono, R.; Marini, R. D.; Hubert, P.; Ziemons, E.
Talanta2019,202, 469−478.
(22) Wu, N.; Balayssac, S.; Danoun, S.; Malet-Martino, M.; Gilard, V.Molecules2020,25, 1193.
(23) Waffo Tchounga, C. A.; Sacre, P. Y.; Ciza, P.; Ngono, R.;
Ziemons, E.; Hubert, Ph.; Marini, R. D.J. Pharm. Biomed. Anal.2021, 194, 113761.
(24) Öman, C. B.; Gamaniel, K. S.; Addy, M. E.Anal. Chem.2006, 78(15), 5273−5276.
(25) World Health Organization. WHO list of prequalified quality control laboratories. 2020, https://extranet.who.int/pqweb/sites/
default/files/documents/PQ_QCLabsList_28.pdf (accessed 2021- 01-13).
(26) Kaale, E.; Risha, P.; Layloff, T.J. Chromatogr. A2011,1218 (19), 2732−2736.
(27) Jahnke, R.Manual Accompanying the GPHF-Minilab, a Concise Quality Control Guide on Essential Drugs and other Medicines, Vol.II on Thin Layer Chromatographic Tests; Global Pharma Health Fund e.V.:
Darmstadt, Germany, 2008.
(28) Kaale, E.; Manyanga, V.; Makori, N.; Jenkins, D.; Michael Hope, S.; Layloff, T.Trop. Med. Int. Health2014,19(6), 747−751.
(29) Kovacs, S.; Hawes, S. E.; Maley, S. N.; Mosites, E.; Wong, L.;
Stergachis, A.PLoS One2014,9(3), e90601.
Analytical Chemistry pubs.acs.org/ac Perspective
https://doi.org/10.1021/acs.analchem.1c00839 Anal. Chem.2021, 93, 8107−8115 8114
(30) Boone, C. M.; Waterval, J. C. M.; Lingeman, H.; Ensing, K.;
Underberg, W. J. M.J. Pharm. Biomed. Anal.1999,20(6), 831−863.
(31) Houbart, V.; Fillet, M. Advances in Low Volume Sample Analysis Using Microfluidic Separation Techniques. In Advances in Microfluidics−New Applications in Biology, Energy, and Materials Sciences; InTechOpen, 2016;DOI: 10.5772/64952.
(32) Jorgenson, J. W.; Lukacs, K. D. Anal. Chem. 1981, 53 (8), 1298−1302.
(33) Heiger, D. N.High Performance Capillary Electrophoresis: An Introduction. Hewlett-Packard, Waldbronn, Germany, 1992, 101.
(34) Kautenburger, R.; Sander, J. M.; Hein, C.Electrophoresis2017, 38, 930−937.
(35) Sato, Y.; Hoshino, H.; Iki, N.J. Inorg. Biochem.2016,161, 122−
127.
(36) Matczuk, M.; Legat, J.; Scaletti, F.; Messori, L.; Timerbaev, A.
R.; Jarosz, M.J. Chromatogr. A2017,1499, 222−225.
(37) Fu, X.; Xiao, H. T.; Liang, S.; Bao, J. J.; Li, T. X.; Zhang, Y.
Analyst2016,141, 305−310.
(38) Nkuipou-Kenfack, E.; Schanstra, J. P.; Bajwa, S.; Pejchinovski, M.; Vinel, C.; Dray, C.; Valet, P.; Bascands, J. L.; Vlahou, A.; Koeck, T.; Borries, M.; Busch, H.; Bechtel-Walz, W.; Huber, T. B.; Rudolph, K. L.; Pich, A.; Mischak, H.; Zurbig, P. PLoS One 2017, 12 (2), e0166875.
(39) Rossing, K.; Bosselmann, H. S.; Gustafsson, F.; Zhang, Z. Y.;
Gu, Y. M.; Kuznetsova, T.; Nkuipou-Kenfack, E.; Mischak, H.;
Staessen, J. A.; Koeck, T.; Schou, M. PLoS One 2016, 11 (6), e0157167.
(40) Cela, A.; Madr, A.; Glatz, Z.J. Chromatogr. A2017,1499, 203−
210.
(41) Bernardo-Bermejo, S.; Sanchez-Lopez, E.; Castro-Puyana, M.;
Marina, M. L.TrAC, Trends Anal. Chem.2020,124, 115807.
(42) Krait, S.; Konjaria, M.-L.; Scriba, G. K. E.Electrophoresis2021, DOI: 10.1002/elps.202000359.
(43) Yamamoto, H.; Sasaki, K.Electrophoresis2017,38, 1053−1059.
(44) Saavedra, I.; García, A.; Barbas, C.J. Chromatogr. A2000,881, 395−401.
(45) Navarro-Pascual-Ahuir, M.; Lerma-García, M. J.; Simó-Alfonso, E. F.; Herrero-Martínez, J. M.Food Anal. Methods2017,10, 3991− 4002.
(46) Pont, L.; Barbosa, J.; Benavente, F.Microchem. J.2020,158, 105204.
(47) Mantovani, V.; Galeotti, F.; Maccari, F.; Volpi, N. Electro- phoresis2018,39, 179−189.
(48) Wang, X.; Li, K.; Yao, L.; Wang, C.; Van Schepdael, A. J.
Pharm. Biomed. Anal.2018,147, 278−287.
(49) Kubáň, P.; Dvořák, M.; Kubáň, P.Anal. Chim. Acta2019,1075, 1−26.
(50) van Tricht, E.; Geurink, L.; Backus, H.; Germano, M.; Somsen, G. W.; Sanger-van de Griend, C. E.Talanta2017,166, 8−14.
(51) Bettonville, V.; Nicol, J. T. J.; Thelen, N.; Thiry, M.; Fillet, M.;
Jacobs, N.; Servais, A. C.Electrophoresis2016,37(4), 579−586.
(52) Pearce, J. M.Phys. Teach.2007,45(3), 164−167.
(53) Kubáň, P.; Foret, F.; Erny, G.Electrophoresis2019,40(1), 65−
78.
(54) Furter, J. S.; Boillat, M.-A.; Hauser, P.Electrophoresis2020,41, 2075−2082.
(55) Drevinskas, T.; Kaljurand, M.; Maruška, A.Electrophoresis2014, 35, 2401−2407.
(56) Stojkovic, M.; Schlensky, B.; Hauser, P. C.Electroanalysis2013, 25(12), 2645−2650.
(57) Takeuchi, M.; Li, Q. Y.; Yang, B. C.; Dasgupta, P. K.; Wilde, V.
E.Talanta2008,76(3), 617−620.
(58) Quero, R. F.; Bressan, L. P.; da Silva, J. A. F.; de Jesus, D. P.
Sens. Actuators, B2019,286, 301−305.
(59) Tan, M. L.; Zhang, M.; Li, F.; Maya, F.; Breadmore, M. C.J.
Chromatogr. A2019,1595, 215−220.
(60) Cabot, J. M.; Breadmore, M. C.; Paull, B. Anal. Chim. Acta 2018,1000, 283−292.
(61)http://pharmelp.ch(accessed 2021-02-11).
(62) Lewis, A. P.; Cranny, A.; Harris, N. R.; Green, N. G.; Wharton, J. A.; Wood, R. J.; Stokes, K. R.Meas. Sci. Technol.2013,24, 042001.
(63) Sastre Torano, J.; Ramautar, R.; de Jong, G.J. Chromatogr. B:
Anal. Technol. Biomed. Life Sci.2019,1118−1119, 116−136.
(64) Remínek, R.; Foret, F.Electrophoresis2021,42(1−2), 19−37.
(65) Gregus, M.; Foret, F.; Kubáň, P.J. Chromatogr. A2016,1427, 177−185.
(66) Mai, T.; Pham, T.; Pham, H.; Saiz, J.; Ruiz, C.; Hauser, P.Anal.
Chem.2013,85(4), 2333−2339.
(67) Pan, J.-Z.; Fang, P.; Fang, X.-X.; Hu, T.-T.; Fang, J.; Fang, Q.
Sci. Rep.2018,8, 1791.
(68) Staub, A.; Rudaz, S.; Veuthey, J.-L.; Schappler, J.J. Chromatogr.
A2010,1217, 8041−8047.
(69) Kubáň, P.; Nguyen, H.; Macka, M.; Haddad, P.; Hauser, P.
Electroanalysis2007,19, 2059−2065.
(70) Drevinskas, T.; Maruska, A.; Girdauskas, V.; Duda, G.;
Gorbatsova, J.; Kaljurand, M.Anal. Methods2020,12, 4977−4986.
(71)https://www.arduino.cc/(accessed 2021-02-10).
(72)https://www.raspbaerrypi.org/(accessed 2021-02-10).
(73) Dubsky, P.; Ordogova, M.; Maly, M.; Riesova, M. J.
Chromatogr. A2016,1445, 158−165.
(74) Jaros, M.; Soga, T.; van de Goor, T.; Gas, B.Electrophoresis 2005,26(10), 1948−1953.
(75) https://web.natur.cuni.cz/gas/simul.html (accessed 20.04.2021).
(76)https://github.com(accessed 2021-04-20).
(77) Marini, R. D.; Rozet, E.; Montes, M. L. A.; Rohrbasser, C.;
Roht, S.; Rhème, D.; Bonnabry, P.; Schappler, J.; Veuthey, J.-L.;
Hubert, Ph.; Rudaz, S.J. Pharm. Biomed. Anal.2010,53, 1278−1287.
(78) Sarr, S.; Diop, E.; Diop, A.; Atouni, A.; Ndiaye, S.; Wafo Tchounga, C.; Gueye, R.; Thiam, K.; Wane, T.; Sarr, A.; Ndiaye, B.;
Rudaz, S.; Diop, Y.Int. J. Mod. Anal. Sep. Sci.2016,5, 1−11.
(79) Guichard, N.; Tobolkina, E.; El Morabit, L.; Bonnabry, P.;
Vernaz, N.; Rudaz, S.Electrophoresis2021,42, 708−718.
(80)http://portasap.eu/(accessed 2021-02-01).
(81) Ryvolová, M.; Macka, M.; Ryvolová, M.; Preisler, J.; Macka, M.
TrAC, Trends Anal. Chem.2010,29(4), 339−353.
