Determination of counterfeit medicines by Raman spectroscopy: Systematic study based on a large set of model tablets

Economic barriers to prevent the smuggling of health goods in Iran

INTRODUCTION

In recent years, smuggling of health goods has apparently increased in the country. Despite the preventive and regulatory measures taken to combat this problem, the outcomes seem to be undesirable. This study thus aims to identify and elucidate the role of economic barriers in the prevention of smuggling health goods in Iran.

METHOD

We conducted semistructured interviews with 29 purposefully identified key informants in the detection, prevention and control of health goods smuggling in different organisations, between May 2021-January 2022. An inductive data-driven thematic analysis approach was further adopted to identify patterns of meaning, using MAXQDA 2020 software to facilitate data management.

RESULTS

We identified four main themes representing the economic barriers to prevent the smuggling of health goods in Iran; Monetary and financial policy, which includes subthemes of financial rules and procedures, market regulation, economic incentives and imbalanced development; Behavioural patterns, consisting of consumer behaviour, the opportunism of smugglers, the behaviour of statesmen and politicians; Economic diplomacy, categorised into international relations and interactions, relations and interactions in the national arena, interaction with non-governmental organisations and Health economic monitoring and evaluation including transparency of statistics and economic information and supervision.

CONCLUSION

Smuggling health goods has become a concerning challenge in the health sector. It is, therefore, imperative to develop and implement appropriate policies and operations towards security and international cooperation, lobbying and coalition-building. Demonopolisation, creating competitive and dynamic markets, removal of rent-seeking layers at all levels, and the use of commercial diplomacy to reduce the burden of smuggling in the health sector of Iran, and perhaps beyond might be of sizeable use to combat such challenge.

Spectral insights: Navigating the frontiers of biomedical and microbiological exploration with Raman spectroscopy

Raman spectroscopy (RS), a powerful analytical technique, has gained increasing recognition and utility in the fields of biomedical and biological research. Raman spectroscopic analyses find extensive application in the field of medicine and are employed for intricate research endeavors and diagnostic purposes. Consequently, it enjoys broad utilization within the realm of biological research, facilitating the identification of cellular classifications, metabolite profiling within the cellular milieu, and the assessment of pigment constituents within microalgae. This article also explores the multifaceted role of RS in these domains, highlighting its distinct advantages, acknowledging its limitations, and proposing strategies for enhancement.

Overview of cocaine identification by vibrational spectroscopy and chemometrics

The use of non-destructive forensic methods for cocaine identification is of outstanding importance, given the amount of samples seized. Techniques such as ATR-FTIR, Raman, and NIR spectroscopy have become alternatives to circumvent this problem, as they allow fast, cheap analysis, and enable the reanalysis of samples. When combined with chemometrics, these spectroscopic methods can be used to determine and quantify cocaine samples, meaning that the limitations of existing techniques can be overcome. This review article covers spectroscopic techniques for identifying cocaine in different forms and matrices, such as food and textiles, which are materials used for smuggling. The chemometric identification of cocaine in oral fluid and water is also discussed. In addition, vibrational spectroscopy techniques using portable equipment are described. This work seeks to evaluate the main chemometric applications of spectroscopic data and to find new perspectives on the identification of cocaine using chemometrics.

A feasibility study on the use of a pocket-sized NIR spectrometer and multivariate algorithm to distinguish expired drugs from unexpired ones

An onsite technique for determining drug integrity in sub-Saharan Africa is needed to ensure drug integrity and enhance public health. This current study presents the application of handheld NIR spectroscopic and multivariate techniques for the accurate identification of unexpired drugs from expired ones. A total of 150 drugs comprising 75 drug samples each of antimalarial (40 unexpired and 35 expired) and antibiotics (40 unexpired and 35 expired) were used in the study. Principal component (PC) analysis was used to extract relevant information from the spectral fingerprint and pre-processed using different techniques comparatively to observe the best cluster trends. The performance of three multivariate algorithms: RF, SVM, and PLS-DA were compared after optimization by cross-validation. The results revealed that SVM and PLS-DA were superior with an identification rate for both antimalarial and antibiotic authenticity prediction above 98% at 5 PCs in both the prediction set and calibration set. For simultaneous prediction of expired and unexpired drugs, we achieved a 100% identification rate. Generally, the results show that handheld NIR spectrometers coupled with smartphone devices could successfully be used to identify unexpired antimalarial and antibiotic drugs from expired antimalarial and antibiotic drugs for effective quality assurance in poor-resource countries. This offers positive feasibility for an affordable and user-friendly approach to reducing drug fraud in Africa.

Research Progress of Raman Spectroscopy and Raman Imaging in Pharmaceutical Analysis

The analytical investigation of the pharmaceutical process monitors the critical process parameters of the drug, beginning from its development until marketing and postmarketing, and appropriate corrective action can be taken to change the pharmaceutical design at any stage of the process. Advanced analytical methods, such as Raman spectroscopy, are particularly suitable for use in the field of drug analysis, especially for qualitative and quantitative work, due to the advantages of simple sample preparation, fast, nondestructive analysis speed, and effective avoidance of moisture interference. Advanced Raman imaging techniques have gradually become a powerful alternative method for monitoring changes in polymorph distribution and active pharmaceutical ingredient distribution in drug processing and pharmacokinetics. Surface-enhanced Raman spectroscopy (SERS) has also solved the inherent insensitivity and fluorescence problems of Raman, which has made good progress in the field of illegal drug analysis. This review summarizes the application of Raman spectroscopy and imaging technology, which are used in the qualitative and quantitative analysis of solid tablets, quality control of the production process, drug crystal analysis, illegal drug analysis, and monitoring of drug dissolution and release in the field of drug analysis in recent years.

Raman Imaging as a powerful tool to elucidate chemical processes in a matrix: Medicated chewing gums with nicotine

Extruded medicated chewing gum is a convenient but complex drug delivery system. Description of gum ingredient distribution and interactions in literature is sparse, but fundamental in product characterization and stability prediction. Although Raman spectroscopy has been used for such characterization of numerous dosage forms, its applicability to medicated chewing gum has not been studied until now. The objective was to investigate the applicability of confocal Raman imaging on chewing gum for identification and distribution of excipients and the model drug nicotine, including changes occurring during shelf life. A sample preparation protocol was composed to present an even surface of a gum cross section without altering the gum matrix texture. High-resolution Raman maps were obtained by Non Negative Least Squares (NNLS) analysis for a reference gum and gums stored for 6 months at mild (25 °C/60% RH) and accelerated (40 °C/75% RH) conditions. Additional Empty Modelling™ analysis confirmed the results of NNLS. The NNLS analysis located nicotine and the following excipients: gum base, calcium carbonate, sorbitol, xylitol, sodium carbonate, sodium bicarbonate and talc in distinct domains of the reference sample. Changes of the sample stored at accelerated conditions was discovered as sodium carbonate was not observed in this sample. Additionally, stereo light microscopy showed changes in product appearance and high-performance liquid chromatography confirmed formation of the oxidation product nicotine-1'-N-oxide in this sample. The gum formulation and its ingredients displayed characteristic Raman spectra, proving Raman imaging as a useful method for characterizing medicated chewing gums, including changes occurring during stability testing.

Raman Imaging of Pathogenic Candida auris: Visualization of Structural Characteristics and Machine-Learning Identification

Invasive fungal infections caused by yeasts of the genus Candida carry high morbidity and cause systemic infections with high mortality rate in both immunocompetent and immunosuppressed patients. Resistance rates against antifungal drugs vary among Candida species, the most concerning specie being Candida auris, which exhibits resistance to all major classes of available antifungal drugs. The presently available identification methods for Candida species face a severe trade-off between testing speed and accuracy. Here, we propose and validate a machine-learning approach adapted to Raman spectroscopy as a rapid, precise, and labor-efficient method of clinical microbiology for C. auris identification and drug efficacy assessments. This paper demonstrates that the combination of Raman spectroscopy and machine learning analyses can provide an insightful and flexible mycology diagnostic tool, easily applicable on-site in the clinical environment.

Checking counterfeiting of pharmaceutical products by attenuated total reflection mid-infrared spectroscopy

Pharmaceutical products serve as the cornerstone of our healthcare system. Product quality is of paramount importance to safety and efficacy of the patients. The success of pharmaceuticals has led to attempts by dubious manufacturers to gain via counterfeiting of the products, while risking the lives of the billions of patients that depend on these products. As a result, there is critical need for an analytical tool that is simple to operate, is robust and lends itself to yielding a rapid fingerprint of a pharmaceutical. In this paper we suggest use of attenuated total reflection (ATR) mid-infrared spectroscopy as a tool for rapid fingerprinting of pharmaceuticals. Antibiotics have been used as a case study to demonstrate the utility of this approach. ATR mid-infrared spectra obtained from powdered solid pharmaceutical products were classified using multivariate data analysis. A partial least-squares discriminant analysis model was developed and tested using 57 pharmaceutical products (27 antibiotics). The model was able to predict antibiotic present in pharmaceutical formulation irrespective of brand or manufacturing process with a classification accuracy of 87.3%. This indicated that the model is robust with respect to variability in pharmaceutical formulations. In addition, the brand/manufacturing company of an antibiotic could be predicted by training a principal component analysis model for specific antibiotic to a classification accuracy of 90%. The results demonstrate the utility of the proposed approach, which can be used by the appropriate authorities for checking on counterfeiting of pharmaceutical products.

Current challenges in the detection and analysis of falsified medicines

Falsified medicines affect public health all around the globe. Complex distribution routes, illegal online webshops and reuse of packaging materials make them hard to detect. In order to tackle this problem, detection methods for the recognition of suspicious medicines and subsequent confirmation of falsification by analytical techniques is required. In this review, we focus on the developments and challenges that existed in the last five years (2015-2020) in the detection and analysis of falsified medicines. These challenges might have not been solved yet or arisen with new types of falsifications, new analytical techniques or detection strategies. Detection of suspicious medicines starts with visual inspection of packaging materials. However, re-use of packaging materials and high-quality imitations complicate visual inspection. Recent developments in the analysis of packaging by microscopic and spectroscopic techniques such as optical microscopy, X-ray fluorescence, infrared spectroscopy and Raman spectroscopy or microscopy, in combination with multivariate analysis show promising results in the detection of falsified medicines. An ongoing big challenge in the analysis of falsified medicines is the affordability of analytical devices. Yet, recent reports showed that lower cost devices, such as Counterfeit Drug Indicator or Counterfeit Detection device version 3 show promising use in the detection of falsified medicines. Furthermore, combining the outcomes of different low-cost analytical techniques, such as Minilab, colorimetry and Counterfeit Drug Indicator significantly increased selectivity and sensitivity in the detection of falsified medicines. Also, recent developments make it possible to link a low-cost technique, such as TLC, to mobile phones. Proper training of personnel has shown room for improvement and remains a challenge, even for relatively simple techniques. With an increased use of analytical fingerprints, an upcoming challenge is the accessibility of the growing pool of data. There is also the need of validated reference libraries on both national and international levels. Developments of the last few years bring us a step closer in the fight against falsified medicines, however challenges remain in the worldwide accessibility of affordable, easily operable and sensitive techniques.

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.

The silent development of counterfeit medications in developing countries - A systematic review of detection technologies

Drug counterfeiting detection is very important for the safety of patients around the world. Counterfeit pharmaceutical products can be referred to the production and distribution of mislabeled medications in which the identity, authenticity, and/or effectiveness is altered. Drugs are often counterfeited to reduce manufacture costs, while still marketing it at as an authentic product. Increased incidence of drug counterfeiting is most noticeable in developing countries, which may not have the resources to supply counterfeit detection devices at a large scale. It is important to consider the direct problems that it may cause and to propose options for controlling and reducing the prevalence of counterfeit medications. Certain counterfeit detection devices have been successfully used for qualitative and quantitative assessment to differentiate counterfeit medications from the reference product. Different technologies are needed to identify the chemical properties of a questioned drug product, which can then be used to determine its authenticity. This review examines the implications of counterfeit medications and the current technological approaches that are able to detect counterfeited pharmaceuticals.

Portable and benchtop Raman spectrometers coupled to cluster analysis to identify quinine sulfate polymorphs in solid dosage forms and antimalarial drug quantification in solution by AuNPs-SERS with MCR-ALS

This paper proposes for the first time: (a) a qualitative analytical method based on portable and benchtop backscattering Raman spectrometers coupled to hierarchical cluster analysis (HCA) and multivariate curve resolution - alternating least-squares (MCR-ALS) to identify two polymorphs of antimalarial quinine sulfate in commercial pharmaceutical tablets in their intact forms and (b) a quantitative analytical method based on gold nanoparticles (AuNPs) as active substrates for surface-enhanced Raman scattering (SERS) in combination with MCR-ALS to quantify quinine sulfate in commercial pharmaceutical tablets in solution. The pure concentration and spectral profiles recovered by MCR-ALS proved that both formulations present different polymorphs. These results were also confirmed by two clusters observed in the HCA model, according to their similarities within and among the samples that provided useful information about the homogeneity of different pharmaceutical manufacturing processes. AuNPs-SERS coupled to MCR-ALS was able to quantify quinine sulfate in the calibration range from 150.00 to 200.00 ng mL-1 even with the strong overlapping spectral profile of the background SERS signal, proving that it is a powerful ultrahigh sensitivity analytical method. This reduced linearity was validated throughout a large calibration range from 25.00 to 175.00 μg mL-1 used in a reference analytical method based on high performance liquid chromatography with a diode array detector (HPLC-DAD) coupled to MCR-ALS for analytical validation purposes, even in the presence of a coeluted compound. The analytical methods developed herein are fast, because second-order chromatographic data and first-order SERS spectroscopic data were obtained in less than 6 and 2 min, respectively. Concentrations of quinine sulfate were estimated with low root mean square error of prediction (RMSEP) values and a low relative error of prediction (REP%) in the range 1.8-4.5%.

Raman spectroscopy and mapping technique for the identification of expired drugs

As expired medical products can be repackaged and sold by unscrupulous counterfeiters, it is essential to find a rapid and convenient method for distinguishing expired and unexpired drugs. Standard detection methods such as high-performance liquid chromatography (HPLC) and thin-layer chromatography are complex, time-consuming, and require organic solvents (that are environmentally unfriendly). Additionally, the Pharmacopoeia publications do not include information about identifying expired drugs. In this study, we proposed a novel method for identifying expired medications based on Raman spectra and verified it using >20 types of expired (Old) and unexpired (New) drugs, each type from the same manufacturer. A portable Raman spectrometer was used to collect Raman spectra of all samples and the similarities between the Old and New drugs (S_N-O) were evaluated. Drugs with S_N-O values <0.9 were classified directly as expired drugs. For drugs with S_N-O values >0.9, the content of active pharmaceutical ingredient (API) might be so low (below or around 10 wt%) that its Raman signal is largely obscured by that of the excipients. In such cases, changes in the API content are undetectable using the portable instrument. Therefore, we adopted Raman mapping technology and established a virtual imaging map to locate areas of high API content. The similarities between the Old or New spectrum and that of the API (S_O-A and S_N-A, respectively) were calculated after removing the signal from the excipients. Our novel methods provide a precise, rapid, convenient, and environmentally friendly way to identify expired drugs that is more effective than the standard HPLC assay.

Comparing the qualitative performances of handheld NIR and Raman spectrophotometers for the detection of falsified pharmaceutical products

Over the last decade, the growth of the global pharmaceutical market has led to an overall increase of substandard and falsified drugs especially on the African market (or emerging countries). Recently, several methods using handheld/portable vibrational spectroscopy have been developed for rapid and on-field drug analysis. The objective of this work was to evaluate the performances of various NIR and Raman handheld spectrophotometers in specific brand identification of medicines through their primary packaging. Three groups of drug samples (artemether-lumefantrine, paracetamol and ibuprofen) were used in tablet or capsule forms. In order to perform a critical comparison, the analytical performances of the two analytical systems were compared statistically using three methods: hierarchical clustering algorithm (HCA), data-driven soft independent modelling of class analogy (DD-SIMCA) and hit quality index (HQI). The overall results show good detection abilities for NIR systems compared to Raman systems based on Matthews's correlation coefficients, generally close to one. Raman systems are less sensitive to the physical state of the samples than the NIR systems, it also suffers of the auto-fluorescence phenomenon and the signal of highly dosed active pharmaceutical ingredient (e.g. paracetamol or lumefantrine) may mask the signal of low-dosed and weaker Raman active compounds (e.g. artemether). Hence, Raman systems are less effective for specific product identification purposes but are interesting in the context of falsification because they allow a visual interpretation of the spectral signature (presence or absence of API).

White powder identification using broadband coherent light in the molecular fingerprint region

We show that a variety of white powder samples, including painkillers, amino acids, stimulants and sugars are readily discriminated by diffuse reflectance infrared spectroscopy involving no preparation of the sample and no physical contact with it. Eleven powders were investigated by illuminating each sample with broadband coherent light in the 8-9-µm band from an OPGaP femtosecond optical parametric oscillator. The spectra of the scattered light were obtained using Fourier-transform spectroscopy. Similarities between different spectra were quantified using Pearson's correlation coefficient, confirming that spectral features in the 8-9-µm wavelength region were sufficient to discriminate between all eleven powders evaluated in the study, offering a route to simple and automated non-contact chemical detection.

Quantitative screening of the pharmaceutical ingredient for the rapid identification of substandard and falsified medicines using reflectance infrared spectroscopy

The World Health Organization suggests that approximately 10% of medicines worldwide are either falsified or substandard with higher figures in low and middle income countries. Such poor quality medicines can seriously harm patients and pose a threat to the economy worldwide. This study investigates attenuated total reflectance-fourier transform infrared (ATR-FTIR) spectroscopy as a simple and rapid method for determination of drug content in tablet dosage forms. Paracetamol was used as the model pharmaceutical ingredient. Spectra of standard mixtures of paracetamol with different excipients formed the basis for multivariate PLS based quantitative analysis of simulated tablet content using different selected infrared absorbance bands. Calibration methods using ATR-FTIR were compared with the ATR-FTIR and conventional ultraviolet spectroscopic analyses of real tablet samples and showed that the paracetamol/microcrystalline cellulose mixtures gave optimum results for all spectral bands tested. The quantitative data for band 1524-1493cm-1 was linear (R2 ˃ 0.98; LOQ ≥ 10%w/w tablet). Global examples of paracetamol tablets were tested using this protocol and 12% of the tablet samples examined was identified as substandard. Each sample analysis was completed in just a few minutes. ATR-FTIR can therefore be used in the rapid screening of tablet formulations. The simplicity of the proposed method makes it appropriate for use in low and middle income countries where analytical facilities are not available.

Infrared spectroscopy and spectroscopic imaging in forensic science

Infrared spectroscopy and spectroscopic imaging, are robust, label free and inherently non-destructive methods with a high chemical specificity and sensitivity that are frequently employed in forensic science research and practices. This review aims to discuss the applications and recent developments of these methodologies in this field. Furthermore, the use of recently emerged Fourier transform infrared (FT-IR) spectroscopic imaging in transmission, external reflection and Attenuated Total Reflection (ATR) modes are summarised with relevance and potential for forensic science applications. This spectroscopic imaging approach provides the opportunity to obtain the chemical composition of fingermarks and information about possible contaminants deposited at a crime scene. Research that demonstrates the great potential of these techniques for analysis of fingerprint residues, explosive materials and counterfeit drugs will be reviewed. The implications of this research for the examination of different materials are considered, along with an outlook of possible future research avenues for the application of vibrational spectroscopic methods to the analysis of forensic samples.

Innovative Strategy for Counterfeit Analysis

Currently, counterfeit medicine is a significant issue for the pharmaceutical world, and it targets all types of therapeutic areas. The health consequences are appalling, since counterfeit medicines can contain impurities and the wrong chemical composition, and can be manufactured and/or stored in dreadful conditions. The provision of fast and reliable analytical tools can contribute to an efficient fight against this phenomenon. In this paper, an analytical strategy based on mobile and forensic laboratories is presented. The mobile equipment, composed of handheld x-ray fluorescence, Raman, infrared, and near-infrared spectrometers, and a handheld microscope, can be used as a first screening tool to detect counterfeits. The counterfeits can then be confirmed in a forensic-dedicated lab in which the chemical composition of the counterfeits is determined to evaluate the danger encountered by the patients. Relevant links with former counterfeit cases then can be revealed based on the analytical data, and can be interpreted from a forensic intelligence perspective in order to provide additional information for law enforcement.