Comparison between counterfeit and authentic medicines: A novel approach using differential scanning calorimetry and hierarchical cluster analysis

Gaussian process regression coupled with mRMR to predict adulterant concentration in cocaine

Street cocaine is often mixed with various substances that intensify its harmful effects. This paper proposes a framework to identify attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) intervals that best predict the concentration of adulterants in cocaine samples. Wavelengths are ranked according to their relevance through ReliefF and mRMR feature selection approaches, and an iterative process removes less relevant wavelengths based on the ranking suggested by each approach. Gaussian Process (GP) regression models are constructed after each wavelength removal and the prediction performance is evaluated using RMSE. The subset balancing a low RMSE value and a small percentage of retained wavelengths is chosen. The proposed framework was validated using a dataset consisting of 345 samples of cocaine with different amounts of levamisole, caffeine, phenacetin, and lidocaine. Averaged over the four adulterants, the GP regression coupled with the mRMR retained 1.07 % of the 662 original wavelengths, outperforming PLS and SVR regarding prediction performance.

Solid state 13C NMR spectroscopy as a tool for identification of counterfeit Viagra tablets and guide for develop new identification approach of falsified product

Counterfeit drugs are a global problem that is directly related to the safety and effectiveness of pharmacotherapy. The black market for counterfeit products is constantly growing and related to the wide availability through online shopping. Therefore, there is a constant need to develop analytical methods that would allow for the unambiguous identification of counterfeit products from the original ones. One of such techniques is solid-state NMR spectroscopy, which allows for direct registration and analysis of spectra of multicomponent solid forms of pharmaceutical formulations. The paper explores the possibility of using this technique in the identification of counterfeit Viagra tablets. In this study, solid-state NMR has been used to detect the non-pharmacopoeial cellulose present in the samples of counterfeit Viagra tablets. Besides, the NMR results allowed to develop a rapid dying technique that can be used to distinguish between the counterfeit and original drug. It has been shown that solid-state NMR spectroscopy allows for numerous analyses such as identification of counterfeit products, assessment of the composition of analyte, estimation of qualitative differences between the original and falsified product, and the development of simple analytical methods based on tablets composition differences.

Application of chemometrics using direct spectroscopic methods as a QC tool in pharmaceutical industry and their validation

This present review described the application of chemometrics using direct spectroscopic methods at the quality control (QC) laboratory of Pharmaceutical Industries. Using chemometrics methods, all QC assessments during the fabrication processes of the drug preparations can be well performed. Chemometrics methods have some advantages compared to the conventional methods, i.e., non-destructive, can be performed directly to intake samples without any extractions, unnecessary performing stability studies, and cost-effective. To achieve reliable results of analyses, all methods must be validated first prior to routine applications. According to the current Pharmacopeia, the validation parameters are specificity/selectivity, accuracy, repeatability, intermediate precision, range, detection limit, quantification limit and robustness. These validation data must meet the acceptance criteria, that have been described by the analytical target profile (ATP) of the drug preparations.

Identification of Enantiomers Using Low-Frequency Raman Spectroscopy

Distinguishing between d and l enantiomers is of important scientific interest, especially for the pharmaceutical industry. Enantiomeric differentiation in the solid form is repeatedly presented as a challenge in the research community. Raman spectroscopy is a nondestructive tool, widely used for the characterization of different materials by probing their vibrational modes. The low-frequency region of the Raman spectrum reveals lattice-level interactions and global fluctuations in the molecule. Lower frequencies correspond to vibrations arising from weaker bonds and long-range interactions and hence are very susceptible to polarization changes. This work presents low-frequency Raman (LFR) spectroscopy as a facile technique to identify enantiomers. The optical setup of conventional Raman spectroscopy is engineered such that the excitation and collection geometries use an asymmetrical focal cone. In addition, a half-wave retarder is added to the excitation path and a Glan-Taylor polarizer is added to the collection path, and these modifications allow us to select the polarization plane for both excitation and collection geometries. The asymmetry in the foci when using a polarized beam for excitation provides different intensities of the collected signal for each polarization plane. In a calibrated system, one can define the chirality of an analyte by comparing the intensity of the LFR signal along orthogonal sets of polarization planes. For nonchiral molecules, the spectral intensity is always higher in the co-polarized plane when compared to the orthogonally depolarized plane, as expected. This contrast in the intensity of Raman spectra serves as a distinct tool for identifying enantiomers.

Identifying the most relevant tablet regions in the image detection of counterfeit medicines

This paper proposes a novel image-based approach to detect counterfeit medicines and identify the most relevant regions of the tablet in the task of classification. Images of medicine tablets undergo an initial pre-processing step which (i) removes the background to find the region of interest, (ii) clusters individual pixels into super-pixels, and (iii) extracts features containing color and texture information. The classification relying on Support Vector Machine (SVM) defines the class the respective image will be inserted into. The task of identifying the relevant regions of the tablets for counterfeiting detection is performed using the concept of support vectors, generating a heat map that indicates the regions that contribute the most to the classification purpose. Two datasets containing images of authentic and counterfeit tablets of Cialis and Viagra were used to validate our propositions, achieving correct classification rates of 100% on both datasets. Regarding the task of identifying the most relevant regions, our proposition outperformed the traditional LIME (Local Interpretable Model-agnostic Explanations) method by yielding more robust explanations.

Facing Counterfeit Medications in Sexual Medicine. A Systematic Scoping Review on Social Strategies and Technological Solutions

Introduction

The counterfeit phenomenon is a largely under-reported issue, with potentially large burden for healthcare. The market for counterfeit drugs used in sexual medicine, most notably type 5 phosphodiesterase inhibitors (PDE5i), is rapidly growing.

Aims

To report the health risks associated with the use of counterfeit medications, the reasons driving their use, and the strategies enacted to contain this phenomenon.

Methods

A systematic scoping review of the literature regarding counterfeit PDE5i was carried between January and June 2021, then updated in August 2021.

Main Outcome Measure

We primarily aimed to clarify the main drivers for counterfeit PDE5i use, the health risks associated, and the currently available strategies to fight counterfeiters.

Results

One hundred thirty-one records were considered for the present scoping review. Production of fake PDE5i is highly lucrative and the lacking awareness of the potential health risks makes it a largely exploitable market by counterfeiters. Adulteration with other drugs, microbial contamination and unreliable dosages make counterfeit medications a cause of worry also outside of the sexual medicine scope. Several laboratory techniques have been devised to identify and quantify the presence of other compounds in counterfeit medications. Strategies aimed at improving awareness, providing antitampering packaging and producing non-falsifiable products, such as the orodispersible formulations, are also described.

Clinical implications

Improving our understanding of the PDE5i counterfeit phenomenon can be helpful to promote awareness of this issue and to improve patient care.

Strengths & Limitations

Despite the systematic approach, few clinical studies were retrieved, and data concerning the prevalence of counterfeit PDE5i use is not available on a global scale.

Conclusion

The counterfeit phenomenon is a steadily growing issue, with PDE5i being the most counterfeited medication with potentially large harmful effects on unaware consumers.

Sansone A, Cuzin B, and Jannini EA. Facing Counterfeit Medications in Sexual Medicine. A Systematic Scoping Review on Social Strategies and Technological Solutions. Sex Med 2021;9:100437.

Combining wavelength importance ranking to the random forest classifier to analyze multiclass spectral data

Near Infrared (NIR) is a type of vibrational spectroscopy widely used in different areas to characterize substances. NIR datasets are comprised of absorbance measures on a range of wavelengths (λ). Typically noisy and correlated, the use of such datasets tend to compromise the performance of several statistical techniques; one way to overcome that is to select portions of the spectra in which wavelengths are more informative. In this paper we investigate the performance of the Random Forest (RF) classifier associated with several wavelength importance ranking approaches on the task of classifying product samples into categories, such as quality levels or authenticity. Our propositions are tested using six NIR datasets comprised of two or more classes of food and pharmaceutical products, as well as illegal drugs. Our proposed classification model, an integration of the χ² ranking score and the RF classifier, substantially reduced the number of wavelengths in the dataset, while increasing the classification accuracy when compared to the use of complete datasets. Our propositions also presented good performance when compared to competing methods available in the literature.

Proof-of-Concept of Detection of Counterfeit Medicine through Polymeric Materials Analysis of Plastics Packaging

The detection of counterfeit pharmaceuticals is always a major challenge, but the early detection of counterfeit medicine in a country will reduce the fatal risk among consumers. Technically, fast laboratory testing is vital to develop an effective surveillance and monitoring system of counterfeit medicines. This study proposed the combination of Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) and Differential Scanning Calorimetry (DSC) for the quick detection of counterfeit medicines, through the polymer analysis of blister packaging materials. A sample set containing three sets of original and counterfeit medicine was analyzed using ATR-FTIR and DSC, while the spectra from ATR-FTIR were employed as a fingerprint for the polymer characterization. Intending to analyze the polymeric material of each sample, DSC was set at a heating rate of 10 °C min^-l and within a temperature range of 0- 400 °C, with nitrogen as a purge gas at a flow rate of 20 ml min^-an. The ATR-FTIR spectra revealed the chemical characteristics of the plastic packaging of fake and original medicines. Further analysis of the counterfeit medicine's packaging with DSC exhibited a distinct difference from the original due to the composition of polymers in the packaging material used. Overall, this study confirmed that the rapid analysis of polymeric materials through ATR-FTIR and comparing DSC thermograms of the plastic in their packaging effectively distinguished counterfeit drug products.

Forensic analysis of anabolic steroids tablets composition using attenuated total reflection Fourier transform infrared microspectroscopy (µATR-FTIR) mapping

The use of falsified and unregistered drugs is a worldwide public health problem. Because these global market products usually do not follow the Good Manufacturing Practices required by health legislation, its composition may be completely different from the original or may contain relevant concentrations of impurities and toxic contaminants. Since anabolic steroids are among the main irregular therapeutic classes seized in Brazil, here we propose a new methodology for analyzing these products, in tablets form, using Attenuated Total Reflection Fourier Transform Infrared Microspectroscopy (µATR-FTIR) mapping. Spectra were acquired from solid tablets by attenuated total reflection, through point mapping methodology. In data processing, a characteristic absorption band for each Active Pharmaceutical Ingredient (API) was integrated and plotted to create its distribution map. This technique was applied in an unprecedented way for the forensic analysis of anabolic steroids and proved to be effective in distinguishing falsified products based on the detection of their APIs. It was possible to detect APIs in 26 out of 30 samples, five of which were classified as falsified only through µATR-FTIR analysis. We were able to create distribution maps of the detected substances associating the microspectroscopic results with characteristic band integration method, which can be used to detect substances and to study samples' homogeneity. We concluded that this methodology is promising for the analysis of anabolic steroid tablets, and can be used in a complementary way with techniques already consolidated in forensic laboratory routine for a better classification of questioned samples between authentic and falsified ones.

Interpol review of controlled substances 2016-2019

This review paper covers the forensic-relevant literature in controlled substances from 2016 to 2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/content/download/14458/file/Interpol%20Review%20Papers%202019.pdf.