Development of Different Separation Techniques for Impurity Profiling of Neostigmine Methylsulfate: A Comparative Study

Different separation techniques have been employed to resolve mixtures of multicomponent preparations over the last few decades. They could be efficiently applied for impurity profiling of active drug substances. Impurity profiling has become a critical procedure in pharmaceutical companies to comply with numerous regulatory standards. Isolation and characterization of impurities are crucial for obtaining data that proves biological safety and efficacy. In this contribution, different HPLC, capillary electrophoresis (CE) and TLC-densitometric methods were developed for the determination of neostigmine methylsulfate (NEO) along with 3-hydroxyphenyltrimethyl ammonium methylsulfate (3-HPA) and 3-dimethylaminophenol (DAP) as its impurities in the presence of citric acid. The linearity for NEO was attained in the range of 5-120 μg/mL and 10-60 μg/mL for the HPLC and CE methods, respectively. Regarding the impurities, linearity was obtained over the range of 10-30 μg/mL for 3-HPA and 5-30 μg/mL for DAP in the two proposed methods. For the TLC method, NEO and DAP were determined within the range of 1-11 μg/band, whereas 3-HPA was assayed over the range of 2-12 μg/band. The suggested methods can be securely utilized for routine analysis of the cited components in quality control laboratories.

Liquid chromatography-quadrupole orbitrap and liquid chromatography-tandem mass spectrometry system for rapid identification and quantitation of thirty nonsteroidal anti-inflammatory drugs and acetaminophen in illegal products

RATIONALE

As the public interest in healthcare increases, illegal dietary supplements, foods, and drugs containing unauthorized pharmaceutical ingredients, including nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen, have been identified. Excessive and unintentional consumption is toxic to the gastrointestinal tract, kidneys, and liver; therefore, these pharmaceuticals must be monitored using analytical methods.

METHODS

A rapid and reliable analysis system involving liquid chromatography-quadrupole orbitrap mass spectrometry (LC-Q-Orbitrap/MS) and liquid chromatography-tandem mass spectrometry (LC/MS/MS) was established and validated to identify and quantify 30 NSAIDs and acetaminophen. In addition, we obtained the MS² spectrum for each component with the proposed structure of the fragment ions.

RESULTS

The analytical method was applied to 505 samples of illicitly distributed dietary supplements, foods, and pharmaceuticals. Non-steroidal analgesics were detected in 126 samples. Carbamazepine (42.9%) and diclofenac (30.2%) were the most detected components in the samples; other pharmaceutical adulterants were also detected in some cases. Additionally, we present the identification of an unknown component, dexamethasone (799 μg/g), using LC-Q-Orbitrap/MS in a sample containing the unknown component with meloxicam (15.4 mg/g).

CONCLUSIONS

The developed analysis system, consisting of qualitative analysis using LC-Q-Orbitrap/MS and quantitative analysis using LC/MS/MS, can rapidly and accurately identify and quantify NSAIDs and acetaminophen while also identifying non-analytical components.

A NIR, 1H-NMR, LC-MS and chemometrics pilot study on the origin of carvedilol drug substances: a tool for discovering falsified active pharmaceutical ingredients

Falsification of drugs, entailing the use of drug substances from unknown unapproved suppliers, is one of the main concerns for the quality of medicines. Therefore, traceability of active ingredients represents an effective tool to fight the illegal trade of medicinal products. In this view, the present pilot study explores the profile of carvedilol active ingredients and possible differences related to the origin. Sixteen samples were examined by near-infrared spectroscopy (NIR), proton nuclear magnetic resonance (¹H-NMR spectrometry) and liquid chromatography mass spectrometry (LC-MS) Q-TOF and the data were analysed by principal component analysis (PCA), cluster analysis and PLSDA discriminant analysis. The results evidenced that the combined information from the three techniques gave good classification of the samples neatly distinguishing the APIs from European countries from the APIs manufactured out of Europe. In particular, NIR spectroscopy provided effective separation between European and non-European manufacturers and ¹H-NMR or LC-MS added specific information related to the separation. Concerning LC-MS Q-TOF, the analysis of multiple isobaric peaks proved to be highly predictive of the drug substance origin and emerged as a promising tool in the field of medicine traceability.

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.

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.

Spectroscopic techniques combined with chemometrics for fast on-site characterization of suspected illegal antimicrobials

The threats of substandard and falsified (SF) antimicrobials, posed to public health, include serious adverse drug effects, treatment failures and even development of antimicrobial resistance. Next to these issues, it has no doubt that efficient methods for on-site screening are required to avoid that SF antimicrobials reach the patient or even infiltrate the legal supply chain. This study aims to develop a fast on-site screening method for SF antimicrobials using spectroscopic techniques (mid infrared, benchtop near infrared, portable near infrared and Raman spectroscopy) combined with chemometrics. 58 real-life illegal antimicrobials (claiming 18 different antimicrobials and one beta-lactamase inhibitor) confiscated by the Belgian Federal Agency for Medicines and Health Products (FAMHP) and 14 genuine antimicrobials were analyzed and used to build and validate models. Two types of models were developed and validated using supervised chemometric tools. One was used for the identification of the active pharmaceutical ingredients (APIs) by applying partial least squares-discriminant analysis (PLS-DA) and another one was used for the detection of non-compliant (overdosed or underdosed) samples by applying PLS-DA, k-nearest neighbors (k-NN) and soft independent modelling by class analogy (SIMCA). The best model capable of identifying amoxicillin and clavulanic acid (co-amoxiclav), azithromycin, co-trimoxazole and amoxicillin was based on the mid-infrared spectra with a correct classification rate (ccr) of 100%. The optimal model capable of detecting non-compliant samples within the combined group of amoxicillin and co-amoxiclav via SIMCA showed a ccr for the test set of 88% (7/8) using mid infrared or benchtop near infrared spectroscopy. The best model for detecting non-compliant samples within the group of amoxicillin via SIMCA was obtained using mid-infrared or Raman spectra, resulting in a ccr of 80% for the test set (4/5) and a ccr for calibration of 100%. For the group of co-amoxiclav, the optimal models showed a ccr of 100% for the detection of non-compliant samples by applying mid-infrared, benchtop near infrared or portable near infrared spectroscopy. Taken together, the obtained models, hyphenating spectroscopic techniques and chemometrics, enable to easily identify suspected SF antimicrobials and to differentiate non-compliant samples from compliant ones.

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.

Evaluating Low-Cost Optical Spectrometers for the Detection of Simulated Substandard and Falsified Medicines

Distribution of substandard and falsified (SF) medicines is on the rise, and its impact on public health, particularly in low-resource countries, is becoming increasingly significant. Portable, nondestructive screening devices can support regulatory authorities in their defense against the spread of SF medicines. Vibrational spectroscopy is an ideal candidate due to its sampling ease and speed. In this work, five portable, among which four are considered low-cost, spectroscopic devices based on near-infrared (NIR), Raman, and mid-infrared (MIR) were evaluated to quantify active pharmaceutical ingredients (APIs) and formulation accuracy within simulated authentic, falsified, and substandard medicines. Binary sample mixtures containing a typical API in antimalarial, antiretroviral, or anti-tuberculosis medicines were assessed. In both univariate and multivariate analyses, the API quantification performance of the digital light processing (DLP) NIR spectrometer and a handheld Raman device consistently matched or exceeded that of the other NIR spectrometers and a scientific grade MIR spectrometer. In the formulation accuracy tests, data from all devices, other than the silicon photodiode array NIR spectrometer, were able to create regression models with less than 6% error. From this exploratory study, we conclude that certain portable NIR devices hold significant promise as cost-effective screening tools for falsified and potentially substandard medicines, and they warrant further investigation and development.

Materials and Technologies to Combat Counterfeiting of Pharmaceuticals: Current and Future Problem Tackling

The globalization of drug trade leads to the expansion of pharmaceutical counterfeiting. The immense threat of low quality drugs to millions of patients is considered to be an under-addressed global health challenge. Analytical authentication technologies are the most effective methods to identify active pharmaceutical ingredients and impurities. However, most of these analytical testing techniques are expensive and need skilled personnel. To combat counterfeiting of drugs, the package of an increasing number of drugs is being protected through advanced package labeling technologies. Though, package labeling is only effective if the drugs are not repackaged. Therefore "in-drug labeling," instead of "drug package labeling," may become powerful tools to protect drugs. This review aims to overview how advanced micro- and nanomaterials might become interesting markers for the labeling of tablets and capsules. Clearly, how well such identifiers can be integrated into "solid drugs" without compromising drug safety and efficacy remains a challenge. Also, incorporation of tags has so far only been reported for the protection of solid drug dosage forms. No doubts that in-drug labeling technologies for "liquid drugs," like injectables which contain expensive peptides, monoclonal antibodies, vaccines, dermal fillers, could help to protect them from counterfeiting as well.

SERS-Active Substrate with Collective Amplification Design for Trace Analysis of Pesticides

Health risks posed by the exposure to trace amounts of pesticide residue in agricultural products have gained a lot of concerns, due to their neurotoxic nature. The applications of surface-enhanced Raman Scattering (SERS) as a detection technique have consistently shown its potential as a rapid and sensitive means with minimal sample preparation. In this study, gold nanoparticles (Au NPs) in elliptical shapes were collected into a layer of ordered zirconia concave pores. The porous zirconia layer (pZrO₂) was then deposited with Au NPs, denoted as Au NPs (x)/pZrO₂, where x indicates the deposition thickness of Au NPs in nm. In the concave structure of pZrO₂, Au-ZrO₂ and Au-Au interactions provide a synergistic and physical mechanism of SERS, which is anticipated to collect and amplify SERS signals and thereafter improve the enhancement factor (EF) of Au NPs/pZrO₂. By taking Rhodamine 6G (R6G) as the test molecule, EF of Au NPs/pZrO₂ might reach to 7.0 × 10⁷. Au NPs (3.0)/pZrO₂ was then optimized and competent to detect pesticides, e.g., phosmet and carbaryl at very low concentrations, corresponding to the maximum residue limits of each, i.e., 0.3 ppm and 0.2 ppm, respectively. Au NPs (3.0)/pZrO₂ also showed the effectiveness of distinguishing between phosmet and carbaryl under mixed conditions. Due to the strong affinities of the phosphoric groups and sulfur in phosmet to the Au NPs (3.0)/pZrO₂, the substrate exhibited selective detection to this particular pesticide. In this study, Au NPs (3.0)/pZrO₂ has thus demonstrated trace detection of residual pesticides, due to the substrate design that intended to provide collective amplification of SERS.

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.

Surface enhanced Raman spectroscopy: A review of recent applications in forensic science

Surface enhanced Raman spectroscopy has many advantages over its parent technique of Raman spectroscopy. Some of these advantages such as increased sensitivity and selectivity and therefore the possibility of small sample sizes and detection of small concentrations are invaluable in the field of forensics. A variety of new SERS surfaces and novel approaches are presented here on a wide range of forensically relevant topics.

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.

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.

Chromatographic fingerprinting as a strategy to identify regulated plants in illegal herbal supplements

Erectile dysfunction (ED) is a sexual disorder characterized by the inability to achieve or maintain a sufficiently rigid erection. Despite the availability of non-invasive oral treatment options, many patients turn to herbal alternatives. Furthermore, herbal supplements are increasingly gaining popularity in industrialized countries and, as a consequence, quality control is a highly important issue. Unfortunately, this is not a simple task since plants are often crushed and mixed with other plants, which complicates their identification by usage of classical approaches such as microscopy. The aim of this study was to explore the potential use of chromatographic fingerprinting to identify plants present in herbal preparations intended for the treatment of ED. To achieve this goal, a HPLC-PDA and a HPLC-MS method were developed, using a full factorial experimental design in order to acquire characteristic fingerprints of three plants which are potentially beneficial for treating ED: Epimedium spp., Pausinystalia yohimbe and Tribulus terrestris. The full factorial design demonstrated that for all three plant references a C8 column (250mm×4.6mm; 5µm particle size) is best suited; methanol and an ammonium formate buffer (pH 3) were found to be the best constituents for the mobile phase. The suitability of this strategy was demonstrated by analysing several self-made triturations in three different botanical matrices, which mimic the influential effects that could be expected when analysing herbal supplements. To conclude, this study demonstrates that chromatographic fingerprinting could provide a useful means to identify plants in a complex herbal mixture.

Counterfeit medicines in Peru: a retrospective review (1997-2014)

OBJECTIVE

To consolidate and assess information on counterfeit medicines subject to pharmaceutical alerts issued by the Peruvian Medicines Regulatory Authority over 18 years (1997-2014) of health monitoring and enforcement.

DESIGN

A retrospective review of drug alerts.

SETTING

A search of the website of the General Directorate of Medicines, Supplies and Drugs (DIGEMID) of the Ministry of Health of Peru for drug alerts issued between 1997 and 2014.

ELIGIBILITY CRITERIA

Drug alerts related to counterfeit medicines.

RESULTS

A total of 669 DIGEMID alerts were issued during the study period, 354 (52.91%) of which cover 1738 cases of counterfeit medicines (many alerts deal with several cases at a time). 1010 cases (58.11%) involved pharmaceutical establishments and 349 (20.08%) involved non-pharmaceutical commercial outlets. In 126 cases (7.25%), counterfeit medicines were seized in an unauthorised trade (without any marketing authorisation); in 253 cases (14.56%) the type of establishment or business associated with the seized product was not identified.

CONCLUSIONS

Counterfeit medicines are a serious public health problem in Peru. A review of the data cannot determine whether counterfeit medicines in Peru increased during the study period, or if monitoring by different government health agencies highlighted the magnitude of the problem by providing more evidence. The problem is clearly structural, since the majority of cases (58.11% of the total) were detected in legitimate supply chains. Most counterfeit medicines involve staple pharmaceutical products and common dosage forms. Considerable work remains to be done to control the serious problem of counterfeit medicines in Peru.

Development and validation of an UHPLC method for the determination of betamethasone valerate in cream, gel, ointment and lotion

An ultra high performance liquid chromatographic method has been developed and validated for the determination of betamethasone valerate (BMV) in topical dermatologic formulations. For the development of the method, response surface methodology based on a three-level full factorial design was used. The eluent composition, the column dimension and the flow rate were chosen as relevant experimental parameters to investigate. The response surface plots revealed an optimum separation by using a RP column (30 mm × 2 mm i.d., 2.2 μm particle size), at 30 °C; isocratic mobile phase consisting of acetonitrile:water (60:40) at a flow rate of 0.2 mL min(-1) and a wavelength set at 254 nm. The proposed method was validated for four types of matrices according to ICH guidelines requirements. Dexamethasone acetate (DMA) was used as internal standard. Linearity was studied in the range of 5-200 μg mL(-1) for BMV in spiked matrix samples. Recoveries were in the range of 95-105% and precision was better than 5% for both analytes, either in cream, gel, ointment, or lotion formulations, when using simple sample preparation. Retention times were 0.95 min for DMA and 1.40 min for BMV, demonstrating a short method run time. The method was successfully applied for routine analysis of dermatological formulations containing betamethasone valerate.

Testing of complementarity of PDA and MS detectors using chromatographic fingerprinting of genuine and counterfeit samples containing sildenafil citrate

Counterfeit medicines are a global threat to public health. High amounts enter the European market, which is why characterization of these products is a very important issue. In this study, a high-performance liquid chromatography-photodiode array (HPLC-PDA) and high-performance liquid chromatography-mass spectrometry (HPLC-MS) method were developed for the analysis of genuine Viagra®, generic products of Viagra®, and counterfeit samples in order to obtain different types of fingerprints. These data were included in the chemometric data analysis, aiming to test whether PDA and MS are complementary detection techniques. The MS data comprise both MS1 and MS2 fingerprints; the PDA data consist of fingerprints measured at three different wavelengths, i.e., 254, 270, and 290 nm, and all possible combinations of these wavelengths. First, it was verified if both groups of fingerprints can discriminate between genuine, generic, and counterfeit medicines separately; next, it was studied if the obtained results could be ameliorated by combining both fingerprint types. This data analysis showed that MS1 does not provide suitable classification models since several genuines and generics are classified as counterfeits and vice versa. However, when analyzing the MS1_MS2 data in combination with partial least squares-discriminant analysis (PLS-DA), a perfect discrimination was obtained. When only using data measured at 254 nm, good classification models can be obtained by k nearest neighbors (kNN) and soft independent modelling of class analogy (SIMCA), which might be interesting for the characterization of counterfeit drugs in developing countries. However, in general, the combination of PDA and MS data (254 nm_MS1) is preferred due to less classification errors between the genuines/generics and counterfeits compared to PDA and MS data separately.

The use of dynamic thermal analysis to distinguish between genuine and counterfeit drugs

WHO estimates that 10% of drugs are falsified. Economic and health factors arising from the use of counterfeit drugs lead to the development of new methods for distinguishing genuine medicines from falsified ones. The purpose of this study was to develop a new, fast, and inexpensive method to distinguish between original and fake drugs. 10 counterfeit Viagra(®) tablets were compared to 4 original pills (Pfizer). The drugs - both original and fake - were heated to 60°C and then the dynamics of their temperature changes at ambient conditions was tested using a thermal imaging camera. The time constants τ showing the dynamics of temperature changes for Viagra(®) and the falsified drug were determined. The thermokinetic parameters of drugs were determined in the temperature range of 60-22.2°C. Both original and counterfeit tablets had different time constants: 171.44 ± 4.62s and 182.71 ± 4.05 s, respectively. Differences in the dynamics of temperature changes as a function of time are particularly pronounced in the range of t+2 to t+7 min. The comparison of the time constants τ enables to distinguish between genuine and counterfeit drugs. The proposed new method which uses dynamic thermal analysis is an effective, cheap and fast technique to distinguish genuine drugs from counterfeit ones.

Identification of (antioxidative) plants in herbal pharmaceutical preparations and dietary supplements

The standard procedures for the identification, authentication, and quality control of medicinal plants and herbs are nowadays limited to pure herbal products. No guidelines or procedures, describing the detection or identification of a targeted plant or herb in pharmaceutical preparations or dietary supplements, can be found. In these products the targeted plant is often present together with other components of herbal or synthetic origin. This chapter describes a strategy for the fast development of a chromatographic fingerprint approach that allows the identification of a targeted plant in herbal preparations and dietary supplements. The strategy consists of a standard chromatographic gradient that is tested for the targeted plant with different extraction solvents and different mobile phases. From the results obtained, the optimal fingerprint is selected. Subsequently the samples are analyzed according to the selected methodological parameters, and the obtained fingerprints can be compared with the one obtained for the pure herbal product or a standard preparation. Calculation of the dissimilarity between these fingerprints will result in a probability of presence of the targeted plant. Optionally mass spectrometry can be used to improve specificity, to confirm identification, or to identify molecules with a potential medicinal or antioxidant activity.

Using the liquid-chromatographic-fingerprint of sterols fraction to discriminate virgin olive from other edible oils

A method to discriminate virgin olive oil from other edible vegetable oils such as, sunflower, pomace olive, rapeseed, canola, corn and soybean, applying chemometric techniques to the liquid chromatographic representative fingerprint of sterols fraction, is proposed. After a pre-treatment of the LC chromatogram data - including baseline correction, smoothing signal and mean centering - different unsupervised and supervised pattern recognition procedures, such as principal component analysis (PCA), hierarchical cluster analysis (HCA), and partial least squares-discriminant analysis (PLSDA), have been applied. From the information obtained from PCA and HCA, two groups can be clearly distinguished (virgin olive and the rest of vegetable oils tested) which have been used to discriminate between two defined classes by means of a PLSDA model. Five latent variables (LVs) explained 76.88% of X-block variance and 95.47% of the defined classes block (γ-block) variance. A root mean square error for calibration and cross validation of 0.10 and 0.22 respectively, confirmed these results and a root mean square error for prediction of 0.15 evidences that the classification model proposed presents an adequate prediction capability. The contingency table also shows the good performance of the model, proving the capability of the LC-R-FpM, to discriminate virgin olive from other vegetable edible oils.

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.

Comparative dissolution study on counterfeit medicines of PDE-5 inhibitors

Counterfeit medicines are a growing problem in both developing and industrialised countries. In general the evaluation of these medicines is limited to the identification and the dosage of the active ingredients. In this study in vitro dissolution tests were conducted on two sets of counterfeit medicines containing PDE-5 inhibitors (sildenafil citrate and tadalafil). The dissolution profiles were statistically compared to the ones of the genuine products using the f₂-method and a comparison at each time point using the Cochran test.

The results showed low equivalences between counterfeit and genuine products as well as higher variations around the mean dissolution value at the different time points for the counterfeit products.