Reliable low-cost capillary electrophoresis device for drug quality control and counterfeit medicines

Advancements in portable instruments based on affinity-capture-migration and affinity-capture-separation for use in clinical testing and life science applications

The shift from testing at centralized diagnostic laboratories to remote locations is being driven by the development of point-of-care (POC) instruments and represents a transformative moment in medicine. POC instruments address the need for rapid results that can inform faster therapeutic decisions and interventions. These instruments are especially valuable in the field, such as in an ambulance, or in remote and rural locations. The development of telehealth, enabled by advancements in digital technologies like smartphones and cloud computing, is also aiding in this evolution, allowing medical professionals to provide care remotely, potentially reducing healthcare costs and improving patient longevity. One notable POC device is the lateral flow immunoassay (LFIA), which played a major role in addressing the COVID-19 pandemic due to its ease of use, rapid analysis time, and low cost. However, LFIA tests exhibit relatively low analytical sensitivity and provide semi-quantitative information, indicating either a positive, negative, or inconclusive result, which can be attributed to its one-dimensional format. Immunoaffinity capillary electrophoresis (IACE), on the other hand, offers a two-dimensional format that includes an affinity-capture step of one or more matrix constituents followed by release and electrophoretic separation. The method provides greater analytical sensitivity, and quantitative information, thereby reducing the rate of false positives, false negatives, and inconclusive results. Combining LFIA and IACE technologies can thus provide an effective and economical solution for screening, confirming results, and monitoring patient progress, representing a key strategy in advancing diagnostics in healthcare.

Characterization of the Interaction of Polymeric Micelles with siRNA: A Combined Experimental and Molecular Dynamics Study

The simulation of large molecular systems remains a daunting challenge, which justifies the exploration of novel methodologies to keep computers as an ideal companion tool for everyday laboratory work. Whole micelles, bigger than 20 nm in size, formed by the self-assembly of hundreds of copolymers containing more than 50 repeating units, have until now rarely been simulated, due to a lack of computational power. Therefore, a flexible amphiphilic triblock copolymer (mPEG45-α-PLL10-PLA25) containing a total of 80 repeating units, has been emulated and synthesized to embody compactified nanoconstructs of over 900 assembled copolymers, sized between 80 and 100 nm, for siRNA complexing purposes. In this study, the tailored triblock copolymers containing a controlled number of amino groups, were used as a support model to address the binding behavior of STAT3-siRNA, in the formation of micelleplexes. Since increasingly complex drug delivery systems require an ever more optimized physicochemical characterization, a converging description has been implemented by a combination of experimentation and computational simulations. The computational data were advantageous in allowing for the assumption of an optimal N/P ratio favoring both conformational rigidifications of STAT3-siRNA with low competitive phenomena at the binding sites of the micellar carriers. These calculations were consistent with the experimental data showing that an N/P ratio of 1.5 resulted in a sufficient amount of complexed STAT3-siRNA with an electrical potential at the slipping plane of the nanopharmaceuticals, close to the charge neutralization.

Capillary Electrophoresis Instruments for Medical Applications and Falsified Drug Analysis/Quality Control in Developing Countries

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.

Low-cost and open-source strategies for chemical separations

In recent years, a trend toward utilizing open access resources for laboratory research has begun. Open-source design strategies for scientific hardware rely upon the use of widely available parts, especially those that can be directly printed using additive manufacturing techniques and electronic components that can be connected to low-cost microcontrollers. Open-source software eliminates the need for expensive commercial licenses and provides the opportunity to design programs for specific needs. In this review, the impact of the "open-source movement" within the field of chemical separations is described, primarily through a comprehensive look at research in this area over the past five years. Topics that are covered include general laboratory equipment, sample preparation techniques, separations-based analysis, detection strategies, electronic system control, and software for data processing. Remaining hurdles and possible opportunities for further adoption of open-source approaches in the context of these separations-related topics are also discussed.

Counterfeit formulations: analytical perspective on anorectics

Purpose

This paper examines the scope of anorectics in counterfeit weight-reducing formulations and provides insight into the present state of research in determining such adulterants. Analytical techniques utilised in profiling adulterants found in slimming products, including limitations and mitigation steps of these conventional methods are also discussed. The current legal status of the anorectics and analogues routinely encountered in non-prescription slimming formulations is also explored.

Methods

All reviewed literature was extracted from Scopus, Web of Science, PubMed, and Google Scholar databases using relevant search terms, such as, ‘counterfeit drugs’, ‘weight loss drugs’, ‘weight-reducing drugs’, ‘slimming drugs’, ‘anorectic agents’, and ‘counterfeit anorexics’. Legislation related to anorectics was obtained from the portals of various government and international agencies.

Results

Anorectics frequently profiled in counterfeit slimming formulations are mostly amphetamine derivatives or its analogues. Five routinely reported pharmacological classes of adulterants, namely anxiolytics, diuretics, antidepressants, laxatives, and stimulants, are mainly utilised as coadjuvants in fake weigh-reducing formulations to increase bioavailability or to minimise anticipated side effects. Liquid and gas chromatography coupled with mass spectrometric detectors are predominantly used techniques for anorectic analysis due to the possibility of obtaining detailed information of adulterants. However, interference from the complex sample matrices of these fake products limits the accuracy of these methods and requires robust sample preparation methods for enhanced sensitivity and selectivity. The most common anorectics found in counterfeit slimming medicines are either completely banned or available by prescription only, in many countries.

Conclusions

Slimming formulations doped with anorectic cocktails to boost their weight-reducing efficacy are not uncommon. Liquid chromatography combined with mass spectrometry remains the gold standard for counterfeit drug analysis, and requires improved preconcentration methods for rapid and quantitative identification of specific chemical constituents. Extensive method development and validation, targeted at refining existing techniques while developing new ones, is expected to improve the analytical profiling of counterfeit anorectics significantly.

Determination of antiretroviral drugs for buyers' club in Switzerland using capillary electrophoresis methods

Human immunodeficiency virus-acquired immunodeficiency syndrome continues to be a major global public health issue, having claimed almost 33 million lives to date. Due to the high cost of antiretroviral treatment, access to these drugs remains difficult for vulnerable populations, such as migrants and people living in prisons, who often do not have health insurance. These factors lead to poorer health outcomes and higher transmission rates. The personal importation scheme for unapproved generics from foreign countries is one option to access affordable human immunodeficiency virus treatment. However, the risk of importing falsified medicine remains high, and the quality control of unapproved drugs is lacking. In this context, three CE methods for the analysis of nine antiviral drugs found in commercial pharmaceutical formulations were evaluated. The selected compounds were emtricitabine, tenofovir disoproxil, tenofovir alafenamide, rilpivirine, efavirenz, raltegravir, dolutegravir, abacavir, and lamivudine. The developed methods were successfully applied to determine the active pharmaceutical ingredients of commercial formulations and unapproved generics. The quality control of unapproved generics by CE is an attractive approach due to its good standard of quality, low cost, ecofriendliness, and ease of implementation.

Protein NMR of biologicals: analytical support for development and marketed products

Application of NMR spectroscopy to derive in-depth characterization of structure and dynamical properties of biomolecules is well established nowadays in many laboratories. Most of these methods rest on the availability of protein labeled with stable isotopes like ¹³C and ¹⁵N. In this report examples are presented on the application of NMR spectroscopic methods to characterize biopharmaceutical proteins in cases no isotope labeled material are available. This is typically found in protein samples used in the development of formulations and production processes. Another important focus of this report is the application of NMR methodology in the field of counterfeit drugs of biologicals and biosimilars. Especially here, NMR does offer relevant structural and quantitative data due to the high versatility of the NMR equipment. An excurse regarding the high medical relevance for a detailed spectroscopic analysis of counterfeits will be presented.

Low-cost automated capillary electrophoresis instrument assembled from commercially available parts

A CE instrument that can be assembled from commercially available components with minimal construction effort is described. Except for the electronic control circuitry no specially made parts are required. It is based on a flexible design of microfluidic, electropneumatic, and electronic sections and different configurations can easily be implemented. Automated injection into the capillary is performed hydrodynamically by the application of a pressure for a controlled length of time. The performance of the device was tested with a contactless conductivity detector by separating different metal ions. In addition, nine metal cations related to the quality of honey were separated in 2.3 min and four honey samples were analysed quantitatively to demonstrate the applicability of the method.

Voltage control for microchip capillary electrophoresis analyses

This paper presents an inexpensive and easy-to-implement voltage sequencer instrument for use in microchip capillary electrophoresis (MCE) actuation. The voltage sequencer instrument takes a 0-5 V input signal from a microcontroller and produces a reciprocally proportional voltage signal with the capability to achieve the voltages required for MCE actuation. The unit developed in this work features four independent voltage channels, measures 105 × 143 × 45 mm (width × length × height), and the cost to assemble is under 60 USD. The system is controlled by a peripheral interface controller and commands are given via universal serial bus connection to a personal computer running a command line graphical user interface. The performance of the voltage sequencer is demonstrated by its integration with a fluorescence spectroscopy MCE sensor using pinched sample injection and electrophoretic separation to detect ciprofloxacin in samples of milk. This application is chosen as it is particularly important for the dairy industry, where fines and health concerns are associated with the shipping of antibiotic-contaminated milk. The voltage sequencer instrument presented represents an effective low-cost instrumentation method for conducting MCE, thereby making these experiments accessible and affordable for use in industries such as the dairy industry.

Quantitative CE analysis of punicalagin in Combretum aculeatum extracts traditionally used in Senegal for the treatment of tuberculosis

Mycobacterium tuberculosis is the causative agent of tuberculosis, an infectious bacterial disease, which most commonly affects the lungs. In the search for novel active compounds or medicines against tuberculosis, an ethnopharmacological survey combined with a host-pathogen assay has recently highlighted the potency of an aqueous extract of Combretum aculeatum. C. aculeatum is used in traditional medicine and has demonstrated a significant in vitro antimycobacterial activity. Punicalagin, an ellagitannin, was isolated and found to be related to the biological activity of the extract. An analytical method for the evaluation of punicalagin in C. aculeatum was developed by capillary electrophoresis. After method optimization, the quantification of punicalagin was achieved for the evaluation of various plant extracts to determine the content of punicalagin related to the extraction modes and conditions, origin of the plant material, and harvesting period. The developed method demonstrated that the leaves presented the highest punicalagin content compared to the seeds and stems. A decoction of 30 min in boiling water was found to be the best extraction mode of C. aculeatum.

A Cross-Sectional Investigation for Verification of Globalization of Falsified Medicines in Cambodia, Indicated by Tablets of Sildenafil Citrate

Medicine falsification is a global issue. Viagra, an erectile dysfunction therapeutic (EDT) medicine consisting primarily of sildenafil citrate, is the most commonly falsified medicine worldwide. Recently falsified EDTs have been reported multiple times in developing countries. The globalization of falsified EDTs has become a concern. In the present study, we selected sildenafil citrate tablets as an indicator and examined samples from a developing country, Cambodia, to investigate the availability of falsified sildenafil tablets in Cambodia and verify the current globalization status of falsified medicines from the standpoint of a developing country. Six samples of the originator Viagra, and 68 samples of generic sildenafil products were purchased from private drug outlets and wholesalers in Phnom Penh, Svay Rieng, and Battambang. The samples’ manufacturers were contacted to authenticate the samples. The quantities and dissolution rates of active ingredients were measured by a high-performance liquid chromatography system with photodiode array. Five generic samples were strongly suspected to be falsified medicines because of their extremely low quality; however, there was little distribution and no falsified medicine alleged to be produced by the originator of Viagra, which charges high prices. That finding indicates that falsification reflects local economic circumstances.

Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR) Combined with Chemometrics Methods for the Classification of Lingzhi Species

Due to the existence of Lingzhi adulteration, there is a growing demand for species classification of medicinal mushrooms by various techniques. The objective of this study was to explore a rapid and reliable way to distinguish between different Lingzhi species and compare the influence of data pretreatment methods on the recognition results. To this end, 120 fresh fruiting bodies of Lingzhi were collected, and all of them were analyzed by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR). Random forest (RF), support vector machine (SVM) and partial least squares discriminant analysis (PLS-DA) classification models were established for raw and pretreated second derivative (SD) spectral matrices to authenticate different Lingzhi species. The results of multivariate statistical analysis indicated that the SD preprocessing method displayed a higher classification ability, which may be attributed to the analysis of powder samples that requires removal of overlapping peaks and baseline shifts. Compared with RF, the results of the SVM and PLS-DA methods were more satisfying, and their accuracies for the test set were both 100%. Among SVM and PLS-DA, the training set and test set accuracy of PLS-DA were both 100%. In conclusion, ATR-FTIR spectroscopy data pretreated by SD combined with PLS-DA is a simple, rapid, non-destructive and relatively inexpensive method to discriminate between mushroom species and provide a good reference to quality assessment.

The health consequences of falsified medicines- A study of the published literature

OBJECTIVES

To analyse and present the literature describing the health consequences of falsified medicines, focusing on mortality and morbidity, as well as the scale of the issue, the geographic extent, the medicines affected, and the harm caused at both the individual and population levels.

METHODS

We searched for articles in PubMed, using pre-optimized keywords '(counterfeit OR fake OR bogus OR falsified OR spurious) AND (medicine OR drug)'. Searches up to February 2017 yielded 2006 hits, of which 1791 were full-length articles in English. Among them, we found 81 papers that qualitatively or quantitatively described 48 incidents in which falsified medicines caused patients to suffer serious adverse effects, injury, symptoms or death.

RESULTS

The distribution of incidents was examined according to the economic status of the countries involved, regional location in the world, therapeutic category of the medicines, number of incidents and victims by year, and characteristics of the falsified medicines. Among the 48 reported incidents, 27 (56.3%) occurred in developing countries and 21 (43.7%) in developed countries. These incidents involved a total of approximately 7200 casualties including 3604 deaths.

CONCLUSIONS

Despite the poor quality of much of the reported data, the results of this study indicate that all types of medications have been targeted for falsification, and falsified medicines have had a serious impact on the health of both adults and children worldwide, with similar numbers of incidents in developing and developed countries.

Recent advances in the capillary electrophoresis analysis of antibiotics with capacitively coupled contactless conductivity detection

This review describes briefly the high rate of counterfeiting of antimicrobial drugs with focus upon its immediate health consequences. The major part of this review encompasses accounts of the improvements achieved in the domain of miniaturization of capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C⁴D). The application of this principle into the development of portable devices as well as its application to counter the health-system-crippling phenomenon of counterfeit antibiotic formulations, are discussed in the context of developing countries.

Species Adulteration in the Herbal Trade: Causes, Consequences and Mitigation

The global economy of the international trade of herbal products has been increasing by 15% annually, with the raw material for most herbal products being sourced from South and Southeast Asian countries. In India, of the 8000 species of medicinal plants harvested from the wild, approximately 960 are in the active trade. With increasing international trade in herbal medicinal products, there is also increasing concern about the widespread adulteration and species admixtures in the raw herbal trade. The adverse consequences of such species adulteration on the health and safety of consumers have only recently begun to be recognised and documented. We provide a comprehensive review of the nature and magnitude of species adulteration in the raw herbal trade, and identify the underlying drivers that might lead to such adulteration. We also discuss the possible biological and chemical equivalence of species that are used as adulterants and substitutes, and the consequences thereof to consumer health and safety, and propose a framework for the development of a herbal trade authentication service that can help regulate the herbal trade market.

Unveiling the Peril of Substandard and Falsified Medicines to Public Health and Safety in Africa: Need for All-Out War to End the Menace

The peril of substandard and falsified medicines (SFM) risk complete failure of the United Nations Sustainable Development Goals on access to safe, effective, quality, and affordable essential medicines in African countries. The global market volume of SFM could be up to US$200 billion, and up to 70% of the total medicines in circulation could be SFM in some parts of Africa. This dominance in the region is a clear sign of SFM proliferation, which continues to cause avoidable health hazards leading to severe adverse effects and devastating loss of human lives, by compromising treatment of chronic, infectious, and life-threatening diseases, such as malaria, cancer, pneumonia, tuberculosis, and diabetes. Besides these consequences to public health and safety, the economic and societal detriments are also grave. Although the recent advancement in detection technology coupled with increased collaborative efforts among some African drug regulatory agencies has led to a considerable success in countering the SFM pandemic, there is need to amplify and intensify such efforts in order to curb or totally eradicate the menace. Here, we provide an overview of the detrimental impact of SFM on the healthcare system in African countries and highlight various strategies for curbing the menace in order to arrest its hazardous consequence to the public.

Fighting falsified medicines: The analytical approach

Given the harm to human health, the fight against falsified medicines has become a priority issue that involves numerous actors. Analytical laboratories contribute by performing analyses to chemically characterise falsified samples and assess their hazards for patients. A wide range of techniques can be used to obtain individual information on the organic and inorganic composition, the presence of an active substance or impurities, or the crystalline arrangement of the formulation's compound. After a presentation of these individual techniques, this review puts forward a methodology to combine them. In order to illustrate this approach, examples from the scientific literature (products used for erectile dysfunction treatment, weight loss and malaria) are placed in the centre of the proposed methodology. Combining analytical techniques allows the analyst to conclude on the falsification of a sample, on its compliance in terms of pharmaceutical quality and finally on the safety for patients.

Review: DNA Barcoding and Chromatography Fingerprints for the Authentication of Botanicals in Herbal Medicinal Products

In the last two decades, there has been a tremendous increase in the global use of herbal medicinal products (HMPs) due to their claimed health benefits. This has led to increase in their demand and consequently, also, resulted in massive adulteration. This is due to the fact that most of the traditional methods cannot identify closely related species in a process product form. Therefore the urgent need for simple and rapid identification methods resulted in the discovery of a novel technique. DNA barcoding is a process that uses short DNA sequence from the standard genome for species identification. This technique is reliable and is not affected by external factors such as climates, age, or plant part. The difficulties in isolation of DNA of high quality in addition to other factors are among the challenges encountered using the DNA barcoding in the authentication of HMP. These limitations indicated that using DNA barcoding alone may ineffectively authenticate the HMP. Therefore, the combination of DNA barcoding with chromatographic fingerprint, a popular and generally accepted technique for the assessment and quality control of HMP, will offer an efficient solution to effectively evaluate the authenticity and quality consistency of HMP. Detailed and quality information about the main composition of the HMPs will help to ascertain their efficacy and safety as these are very important for quality control.

Chemometrics and the identification of counterfeit medicines-A review

This review article provides readers with a number of actual case studies dealing with verifying the authenticity of selected medicines supported by different chemometric approaches. In particular, a general data processing workflow is discussed with the major emphasis on the most frequently selected instrumental techniques to characterize drug samples and the chemometric methods being used to explore and/or model the analytical data. However, further discussion is limited to a situation in which the collected data describes two groups of drug samples - authentic ones and counterfeits.

Microfluidic Breadboard Approach to Capillary Electrophoresis

A breadboard approach for electrophoretic separations with contactless conductivity detection is presented. This is based on miniature off-the-shelf components such as syringe pumps, valves, and pressure controllers which could be set up in a very compact overall arrangement. It has a high flexibility for different tasks at hand, and the common operations of hydrodynamic injection and capillary flushing are automated. For demonstration of the versatility of the proposition, several very diverse configurations and modes of electrophoresis were successfully implemented, namely, standard capillary zone electrophoresis, pressure assisted zone electrophoresis, the simultaneous separation of cations and anions by dual-capillary zone electrophoresis, the separation of cationic amino acids by isotachophoresis, as well as the separation of small carboxylic acids by gradient elution moving boundary electrophoresis. The system also allows fast separations, as demonstrated by the analysis of six inorganic cations within 35 s. The approach addresses respective limitations of either conventional capillary electrophoresis instruments as well as electrophoretic lab-on-chip devices, while maintaining a performance in terms of detection limits and reproducibility comparable to standard instrumentation.

An authenticity survey of herbal medicines from markets in China using DNA barcoding

Adulterant herbal materials are a threat to consumer safety. In this study, we used DNA barcoding to investigate the proportions and varieties of adulterant species in traditional Chinese medicine (TCM) markets. We used a DNA barcode database of TCM (TCMD) that was established by our group to investigate 1436 samples representing 295 medicinal species from 7 primary TCM markets in China. The results indicate that ITS2 barcodes could be generated for most of the samples (87.7%) using a standard protocol. Of the 1260 samples, approximately 4.2% were identified as adulterants. The adulterant focused on medicinal species such as Ginseng Radix et Rhizoma (Renshen), Radix Rubi Parvifolii (Maomeigen), Dalbergiae odoriferae Lignum (Jiangxiang), Acori Tatarinowii Rhizoma (Shichangpu), Inulae Flos (Xuanfuhua), Lonicerae Japonicae Flos (Jinyinhua), Acanthopanacis Cortex (Wujiapi) and Bupleuri Radix (Chaihu). The survey revealed that adulterant species are present in the Chinese market, and these adulterants pose a risk to consumer health. Thus, regulatory measures should be adopted immediately. We suggest that a traceable platform based on DNA barcode sequences be established for TCM market supervision.

Absorbance detector for capillary electrophoresis based on light-emitting diodes and photodiodes for the deep-ultraviolet range

A new absorbance detector for capillary electrophoresis featuring relatively high intensity light-emitting diodes as radiation sources and photodiodes for the deep-UV range was developed. The direct relationship of absorbance values and concentrations was obtained by emulating Lambert-Beer's law with the application of a beam splitter to obtain a reference signal and a log-ratio amplifier circuitry. The performance of the cell was investigated at 255 nm with the detection of sulfanilic, 4-nitrobenzoic, 4-hydroxybenzoic and 4-aminobenzoic acid and the indirect detection of acetate, propionate, butyrate and caproate using benzoate as the displacement dye molecule. Vanillic acid, L-tyrosine and DL-tryptophan as well as the sulfonamides sulfamerazine, sulfathiazole and sulfamethazine were determined at 280 nm. Good linearities over 3 orders of magnitude were obtained. The noise level recorded was as low as 50 μAU and the drift typically <200 μAU/5 min.

Analytical devices based on light-emitting diodes--a review of the state-of-the-art

A general overview of the development of the uses of light-emitting diodes in analytical instrumentation is given. Fundamental aspects of light-emitting diodes, as far as relevant for this usage, are covered in the first part. The measurement of light intensity is also discussed, as this is an essential part of any device based on light-emitting diodes as well. In the second part, applications are discussed, which cover liquid and gas-phase absorbance measurements, flow-through detectors for chromatography and capillary electrophoresis, sensors, as well as some less often reported methods such as photoacoustic spectroscopy.

Counterfeit drugs and medical devices in developing countries

The World Health Organization has reported that counterfeit medicines potentially make up more than 50% of the global drug market, with a significant proportion of these fake products being encountered in developing countries. This occurrence is attributed to a lack of effective regulation and a weak enforcement capacity existing in these countries, with an increase in this trade resulting from the growing size and sophistication of drug counterfeiters. In addition, due to both cost and lack of availability of medicines, consumers in developing countries are more likely to seek out these inexpensive options. The World Health Organization is mindful of the impact of counterfeit drugs on consumer confidence in health care systems, health professionals, the supply chain, and genuine suppliers of medicines and medical devices. Antibiotics, antituberculosis drugs, and antimalarial and antiretroviral drugs are frequently targeted, with reports of 60% of the anti-infective drugs in Asia and Africa containing active pharmaceutical ingredients outside their pharmacopoeial limits. This has obvious public health implications of increasing drug resistance and negating all the efforts that have already gone into the provision of medicines to treat these life threatening conditions in the developing world. This review, while focusing on counterfeit medicines and medical devices in developing countries, will present information on their impact and how these issues can be addressed by regulation and control of the supply chain using technology appropriate to the developing world. The complexity of the problem will also be highlighted in terms of the definition of counterfeit and substandard medicines, including gray pharmaceuticals. Although this issue presents as a global public health problem, outcomes in developing countries where counterfeit drugs to treat malaria, tuberculosis, and human immunodeficiency virus/acquired immunodeficiency syndrome not only result in drug resistance, but a number of deaths from the untreated disease, is in stark contrast with the developed world, where lifestyle drugs such as sildenafil (Viagra®) are most commonly counterfeited.

Technologies for detecting falsified and substandard drugs in low and middle-income countries

Falsified and substandard drugs are a global health problem, particularly in low- and middle-income countries (LMIC) that have weak pharmacovigilance and drug regulatory systems. Poor quality medicines have important health consequences, including the potential for treatment failure, development of antimicrobial resistance, and serious adverse drug reactions, increasing healthcare costs and undermining the public's confidence in healthcare systems. This article presents a review of the methods employed for the analysis of pharmaceutical formulations. Technologies for detecting substandard and falsified drugs were identified primarily through literature reviews. Key-informant interviews with experts augmented our methods when warranted. In order to aid comparisons, technologies were assigned a suitability score for use in LMIC ranging from 0-8. Scores measured the need for electricity, need for sample preparation, need for reagents, portability, level of training required, and speed of analysis. Technologies with higher scores were deemed the most feasible in LMICs. We categorized technologies that cost $10,000 USD or less as low cost, $10,000-100,000 USD as medium cost and those greater than $100,000 USD as high cost technologies (all prices are 2013 USD). This search strategy yielded information on 42 unique technologies. Five technologies were deemed both low cost and had feasibility scores between 6-8, and an additional four technologies had medium cost and high feasibility. Twelve technologies were deemed portable and therefore could be used in the field. Many technologies can aid in the detection of substandard and falsified drugs that vary from the simplest of checklists for packaging to the most complex mass spectrometry analyses. Although there is no single technology that can serve all the requirements of detecting falsified and substandard drugs, there is an opportunity to bifurcate the technologies into specific niches to address specific sections within the workflow process of detecting products.

Understanding and fighting the medicine counterfeit market

Medicine counterfeiting is a serious worldwide issue, involving networks of manufacture and distribution that are an integral part of industrialized organized crime. Despite the potentially devastating health repercussions involved, legal sanctions are often inappropriate or simply not applied. The difficulty in agreeing on a definition of counterfeiting, the huge profits made by the counterfeiters and the complexity of the market are the other main reasons for the extent of the phenomenon. Above all, international cooperation is needed to thwart the spread of counterfeiting. Moreover effort is urgently required on the legal, enforcement and scientific levels. Pharmaceutical companies and agencies have developed measures to protect the medicines and allow fast and reliable analysis of the suspect products. Several means, essentially based on chromatography and spectroscopy, are now at the disposal of the analysts to enable the distinction between genuine and counterfeit products. However the determination of the components and the use of analytical data for forensic purposes still constitute a challenge. The aim of this review article is therefore to point out the intricacy of medicine counterfeiting so that a better understanding can provide solutions to fight more efficiently against it.

Flexibility and applicability of β-expectation tolerance interval approach to assess the fitness of purpose of pharmaceutical analytical methods

An innovative versatile strategy using Total Error has been proposed to decide about the method's validity that controls the risk of accepting an unsuitable assay together with the ability to predict the reliability of future results. This strategy is based on the simultaneous combination of systematic (bias) and random (imprecision) error of analytical methods. Using validation standards, both types of error are combined through the use of a prediction interval or β-expectation tolerance interval. Finally, an accuracy profile is built by connecting, on one hand all the upper tolerance limits, and on the other hand all the lower tolerance limits. This profile combined with pre-specified acceptance limits allows the evaluation of the validity of any quantitative analytical method and thus their fitness for their intended purpose. In this work, the approach of accuracy profile was evaluated on several types of analytical methods encountered in the pharmaceutical industrial field and also covering different pharmaceutical matrices. The four studied examples depicted the flexibility and applicability of this approach for different matrices ranging from tablets to syrups, different techniques such as liquid chromatography, or UV spectrophotometry, and for different categories of assays commonly encountered in the pharmaceutical industry i.e. content assays, dissolution assays, and quantitative impurity assays. The accuracy profile approach assesses the fitness of purpose of these methods for their future routine application. It also allows the selection of the most suitable calibration curve, the adequate evaluation of a potential matrix effect and propose efficient solution and the correct definition of the limits of quantification of the studied analytical procedures.

Capillary electrophoresis for the assay of fixed-dose combination tablets of artesunate and amodiaquine

Background

Quality control of drugs in formulations is still a major challenge in developing countries. For the quality control of artesunate and amodiaquine tablets in fixed-dose combination, only liquid chromatographic methods have been proposed in the literature. There are no capillary electrophoretic methods reported for the determination of these active substances, although this technique presents several advantages over liquid chromatography (long lifetime, low price of the capillary, low volumes of electrolyte consumption) in addition to simplicity. In this paper, a reliable capillary electrophoresis method has been developed and validated for the quality control of these drugs in commercial fixed-dose combination tablets.

Methods

Artesunate and amodiaquine hydrochloride in bilayer tablets were determined by micellar electrokinetic capillary chromatography (MEKC). Analytes were extracted from tablets by sonication with a solvent mixture phosphate buffer pH 7.0-acetonitrile containing benzoic acid as internal standard. Separation was carried out on Beckman capillary electrophoresis system equipped with fused silica capillary, 30 cm long (20 cm to detector) × 50 μm internal diameter, using a 25 mM borate buffer pH 9.2 containing 30 mM sodium dodecyl sulfate as background electrolyte, a 500 V cm⁻¹ electric field and a detection wavelength of 214 nm.

Results

Artesunate, amodiaquine and benzoic acid were separated in 6 min. The method was found to be reliable with respect to specificity,linearity of the calibration line (r² > 0.995), recovery from synthetic tablets (in the range 98–102%), repeatability (RSD 2–3%, n = 7 analytical procedures). Application to four batches of commercial formulations with different dosages gave content in good agreement with the declared content.

Conclusion

The MEKC method proposed is reliable for the determination of artesunate and amodiaquine hydrochloride in fixed-dose combination tablets. The method is well-suited for drug quality control and detection of counterfeit or substandard medicines.