In-silico evaluation of Malawi essential medicines and reactive metabolites for potential drug-induced toxicities.

BACKGROUND: Drug-induced toxicity is one of the problems that have negatively impacted on the well-being of populations throughout the world, including Malawi. It results in unnecessary hospitalizations, retarding the development of the country. This study assessed the Malawi Essential Medicines List (MEML) for structural alerts and reactive metabolites with the potential for drug-induced toxicities. METHODS: This in-silico screening study used StopTox, ToxAlerts and LD-50 values toxicity models to assess the MEML drugs. A total of 296 drugs qualified for the analysis (those that had defined chemical structures) and were screened in each software programme. Each model had its own toxicity endpoints and the models were compared for consensus of their results. RESULTS: In the StopTox model, 86% of the drugs had potential to cause at least one toxicity including 55% that had the potential of causing eye irritation and corrosion. In ToxAlerts, 90% of the drugs had the potential of causing at least one toxicity and 72% were found to be potentially reactive, unstable and toxic. In LD-50, 70% of the drugs were potentially toxic. Model consensus evaluation results showed that the highest consensus was observed between ToxAlerts and StopTox (80%). The overall consensus amongst the three models was 57% and statistically significant (p < 0.05). CONCLUSIONS: A large number of drugs had the potential to cause various systemic toxicities. But the results need to be interpreted cautiously since the clinical translation of QSAR-based predictions depends on many factors. In addition, inconsistencies have been reported between screening results amongst different models.

Prevalence of Substandard Amoxicillin Oral Dosage Forms in the National Capital District of Papua New Guinea.

Antibiotics are commonly reported as being substandard or falsified in low- to middle-income countries, having potential to contribute to the development of antimicrobial resistance and drug-resistant infections. Amoxicillin, used to treat a number of infections and listed by the WHO as an essential medicine, presented as a good drug candidate for this study. We aimed to measure the prevalence of substandard and falsified amoxicillin oral products (tablets, capsules, and suspensions) in the National Capital District of Papua New Guinea (PNG). These oral products were surveyed in 2018 and 2019 from retail pharmacies, private and public health facilities, and the Area Medical Store, representing more than 90% of licensed medicine outlets. The product packaging was visually inspected, and the samples were analyzed for amoxicillin content using a validated high-performance liquid chromatography method. Although no falsified products were identified, 15% of the 190 products analyzed contained substandard amounts of amoxicillin. Quality varied with the dosage form (P = 0.002), with capsules exhibiting the lowest incidence of substandard content (4% in 2019) and tablets collected in 2018 experiencing the highest failure rate (50%). Suspension (40%) quality was compromised by failure to achieve homogeneity on reconstitution. A higher incidence of substandard content (P = 0.002) was associated with one major retail group. Routine testing of medicines by resource-poor countries is often unachievable, leading to the circulation of poor quality drugs, which is a global public health concern. Our study highlighted that substandard amoxicillin oral products are indeed prevalent in the NCD of PNG.

Essential Medicinal Chemistry of Essential Medicines.

Since 1977, the World Health Organization publishes a list of essential medicines, i.e., those that satisfy the priority health care needs of the population and are selected with regard to disease prevalence and public health relevance, evidence of clinical efficacy, and safety, as well as comparative costs and cost-effectiveness. The Essential Medicines List (EML) is an invaluable tool for all countries to select those medicines that have an excellent risk/benefit ratio and that are reputed to be of pivotal importance to health. In the present perspective, we describe the chemical composition and the main features of the small molecules that are included in the EML, spanning from their origin, to their stereochemistry and measure of drug-likeness. Most and foremost, we wish to disseminate the importance of the EML, which can be both a helpful teaching tool in an ever-expanding world of medicines and an inspiration for those involved in pharmaceutical R&D.

Aplicación del Sistema de Clasificación Biofarmacéutica al Cuadro Básico de Medicamentos de Cuba: ¿bioequivalencia in vivo o disolución in vitro? / Application of the Biopharmaceutical Classification System to the Basic Table of Medicines of Cuba: bioequivalence in vivo or dissolution in vitro?

El siguiente trabajo tiene como objetivos clasificar los ingredientes farmacéuticos activos (IFAs) de los sólidos orales de liberación inmediata del Cuadro Básico de Medicamentos de Cuba (CBM) que son producidos nacionalmente, según el Sistema de Clasificación Biofarmacéutica (SCB), y proponer aquellos que podrían demostrar su intercambiabilidad terapéutica a través de ensayos de disolución in vitro. Para ello se utilizó el listado de medicamentos del CBM de Cuba del 2019 y se realiza una clasificación biofarmacéutica provisional consenso, a partir de diferentes clasificaciones biofarmacéuticas publicadas y de una extensiva revisión de la literatura. Se identificó que aproximadamente el 48% de los IFAs del CBM presentan polimorfismo y que el 12,3% de las formas sólidas orales del CBM de Cuba tienen un estrecho margen terapéutico, por lo que no pueden ser bioexonerados mediante estudios de bioequivalencia in vitro basados en el SCB. Se constató que un 50,8% de los IFAs de formas sólidas orales de liberación inmediata del CBM de Cuba han sido clasificados según el SCB por la OMS. La aplicación conjunta de diversas metodologías de clasificación biofarmacéutica permitió clasificar provisionalmente todos los IFAs de las formas sólidas orales del CBM, demostrando que el 66,1% pertenece a las clases I, III y I/III del SCB, por lo que podrían ser bioexonerados de ensayos de bioequivalencia in vivo en humanos

The goals of the present work are to classify the active pharmaceutical ingredients (APIs) of the oral solids of immediate release of the Essential List of Medicines of Cuba (CBM) that are produced nationally, according to the Biopharmaceutical Classification System (BCS), and to propose those that could demonstrate their therapeutic interchangeability through in vitro dissolution tests. For this was used the Cuban CBM drug list of 2019, and a provisional consensus biopharmaceutical classification is proposed, based on different published biopharmaceutical classifications and an extensive review of the literature. It was identified that approximately 48% of the CBM IFAs present polymorphism and that 12.3% of the oral solid forms of CBM in Cuba have a narrow therapeutic margin, for which reason they cannot be bioexonerated through in vitro bioequivalence studies based on BCS. It was found that 50.8% of the oral solid forms of CBM in Cuba have been classified according to SCB by WHO. The joint application of diverse methodologies of biopharmaceutical classification allowed to provisionally classify all the IFAs of the oral solid forms of CBM, demonstrating that 66.1% belongs to classes I, III and I/III of the SCB, reason why they could be biowaivered from in vivo bioequivalence assays in humans

Statistics on BCS classification of generic drug products approved between 2000 and 2011 in the USA.

The Biopharmaceutics Classification system (BCS) classifies drug substances based on aqueous solubility and intestinal permeability. The objective of this study was to use the World Health Organization Model List of Essential Medicines to determine the distribution of BCS Class 1, 2, 3, and 4 drugs in Abbreviated New drug Applications (ANDA) submissions. To categorize solubility and intestinal permeability properties of generic drugs under development, we used a list of 61 drugs which were classified as BCS 1, 2, 3, and 4 drugs with certainty in the World Health Organization Model List of Essential Medicines. Applying this list to evaluation of 263 ANDA approvals of BCS drugs during the period of 2000 to 2011 indicated 110 approvals (41.8%) for Class 1 drugs (based on both biowaiver and in vivo bioequivalence studies), 55 (20.9%) approvals for Class 2 drugs, 98 (37.3%) approvals for Class 3 drugs, and no (0%) approvals for Class 4 drugs. The present data indicated a trend of more ANDA approvals of BCS Class 1 drugs than Class 3 or Class 2 drugs. Antiallergic drugs in Class 1, drugs for pain relief in Class 2 and antidiabetic drugs in Class 3 have received the largest number of approvals during this period.

In vitro evaluation of the quality of essential drugs on the Tanzanian market.

We evaluated the in vitro availability and its stability under simulated tropical conditions of various formulations of four essential drugs marketed in Tanzania. We obtained 22 formulations (containing paracetamol, acetylsalicylic acid, chloroquine or sulphadoxine/pyrimethamine) from wholesale pharmacies in Dar es Salaam and the Medical Stores Department (Tanzania). The drug content, in vitro availability (dissolution) and its stability under simulated tropical conditions were determined using methods specified in the United States Pharmacopoeia (USP) 24 monograph of the respective drugs. All formulations passed the pharmacopoeia requirements for the drug content. However, seven formulations (three acetylsalicylic acid, two sulphadoxine/pyrimethamine and two paracetamol) failed to meet the USP 24 tolerance limits for dissolution. Another five formulations (three paracetamol and two chloroquine) failed to meet the dissolution tolerance limits after being subjected to an accelerated stability test under simulated tropical conditions (75% RH/40 degrees C) for 6 months. The study has demonstrated the presence on the Tanzanian market of essential drug formulations that met potency requirements and yet had unsatisfactory in vitro availability as they were not robust enough to withstand storage under simulated tropical conditions.

[Access for all to quality drugs]. / Accès pour tous aux médicaments de qualité.

The implementation of essential drugs policies and widespread use of generic products in humanitarian programs has ensured access to medication for poverty-stricken populations. However rigorous drug selection according to origin is necessary to guarantee quality. A drug is more than a mixture of chemical components, it depends on a complex balance that can be affected by numerous factors. To be beneficial to the patient, a drug must be manufactured, purchased, distributed and administered in a strictly professional and responsible manner. An obvious danger for drugs such as antibiotics is that use of poor quality products producing insufficient bioavailability will promote development of microbial resistance. This could become a worldwide public health problem with particularly dramatic consequences for the treatment of tuberculosis and retroviruses.