Sylvester O. Eraga

Background: Artemether-lumefantrine (AL) is the first-line treatment for uncomplicated malaria throughout Nigeria. The rise of substandard and falsified medicines endangers patient safety, effective treatment, and antisubstitution for decreased susceptibility to effective treatment. This study evaluated in-vitro pharmaceutical quality of artemether￾lumefantrine brands that are marketed in Benin City. Methods: Sixteen (16) brands of artemether-lumefantrine tablets were procured from Patented and Proprietary Medicine Vendors (PPMVs) and retail pharmacies licensed through NAFDAC throughout Benin City. Samples were evaluated based on pharmacopoeial standards of visual/organoleptic packaging and tablet assessment, weight uniformity, tablet hardness, friability, disintegration time, in-vitro dissolution and assay for % purity of active pharmaceutical ingredients. Results: All 16 brands were NAFDAC-approved and presently active. All samples passed critical evaluative tests associated with weight uniformity, dissolution (all >80% in 60 min), and % purity (assay) with all brands within pharmacopoeial standards of 90.0% - 110.0% meaning active pharmaceutical ingredients are accounted for. However, significant quality concerns were raised as 1 brand (Biolumefar) failed the friability test (3.00% weight loss) due to compromised mechanical integrity. 1 brand (Contrine plus) failed disintegration time analysis as the average time elapsed was >30 min according to pharmacopoeial standards. Finally, a statistically significant difference was found in tablet hardness across all brands (range: 6.50 LP to 11.33 kP). xi
Conclusion: Overall, findings present inconsistent quality. While it is a positive outcome that no brands failed the assay for content of active ingredients, the failure of two brands in the most critical physical assessments - one for friability and one for disintegration -indicates inferior manufacturing processes and quality control standards. Therefore, there is a continued need for post-market surveillance from NAFDAC to ensure all AL products in circulation are quality compliant to avoid malarial treatment failures secondary to drug resistance

Background: Diclofenac is a widely used non-steroidal anti-inflammatory drug (NSAID) prescribed for the management of pain and inflammatory disorders such as arthritis. Despite its therapeutic effectiveness, conventional immediate-release diclofenac formulations are often associated with frequent dosing and increased risk of gastrointestinal irritation due to rapid absorption and elimination. Sustained-release matrix tablet systems have been developed to address these limitations by providing prolonged drug action, reducing dosing frequency, and minimizing adverse effects. The selection and optimization of excipient blends, especially
hydrophilic polymers, play a pivotal role in achieving a desirable sustained-release profile and robust tablet quality.
Objective: This study investigates the effect of polymer blends, specifically hydroxypropyl methylcellulose (HPMC) and maize starch mucilage, in combination with Eudragit RL-100 and
polyethylene glycol (PEG), on the physical properties and drug release characteristics of sustained-release diclofenac sodium matrix tablets. Method: Matrix tablets were manufactured by direct compression, utilizing varying proportions of HPMC and maize starch mucilage as hydrophilic polymer binders within systems also containing Eudragit RL-100 and PEG. All formulations were evaluated for tablet hardness, friability, and disintegration time using standardized pharmacopeial procedures, with an emphasis on comparing physical integrity and sustained-release performance across ten distinct batches

Background: Amlodipine is a third-generation dihydropyridine antihypertensive that blocks calcium on calcium channels used frequently in hypertension and angina. It has even been listed by WHO as an Essential Medicine. Although very practical, it belongs to the Biopharmaceutical Classification System (BCS Class) II - the drug is very permeable across the intestinal wall but very low water solubility. Even the low solubility is the slowest step in absorption which may lead to the release of tablets being not fully done, inconsistent bioavailability between different patients and reliance on food. Consequently, by enhancing solubility of amlodipine we desire to make the administration of amlodipine more effective orally.
Purpose: The purpose of this work was the development, characterization, and testing of solid dispersions (SDs) of amlodipine with Polyvinylpyrrolidone (PVP K30). We thought that the method would help us to change the drug which is not soluble in large quantities but exists as crystals to a high- energy, highly soluble amorphous one. The research rigorously investigated system of varying drug- polymer ratios and characterized the optimally dispersed system completely, as a solubility was demonstrated and the in-vitro rate of solubility was significantly increased.
Material and Methods: Amlodipine solid dispersions through solvent evaporation method were prepared by us. A common organic solvent (ethanol) was used to dissolve the drug as well as the hydrophilic carrier, PVP K30. A rotary evaporator was then used to remove the solvent under reduced pressure leaving a mass of solid. This mass was dried, ground and sieved. Five ratios of drug-polymer weight were made: 1:1, 1: 2, 1:3, 1:4 and 1:5. Lastly, all Solid dispersion had their apparent aqueous solubility determined. And lastly we pressed this optimized powder into tablet form and compared the drug release of this tablet in in-vitro with that of a normal tablet in a dissolution experiment. Results: There was distinct polymer-dose-dependent increase in aqueous solubility of Mamlodipine in the solid dispersions relative to pure, unprocessed amlodipine drug. This ratio was the best solubility enhancer with the highest level of 1:5 (drug: polymer), and it was determined to completely analyze. FTIR of 1:5 Solid dispersion showed the typical peaks of the amlodipine and PVP K30, and no new peak or significant change, meaning strong chemical interaction. The most important was the Differentiated Scanning Calorimetry (DSC) thermogram, which indicated the total loss of the sharp endothermic melting point of crystalline amlodipine, which confirmed the drug had been transformed to a molecularly dispersed or amorphous form. Most importantly, the 1:5 solid dispersion to tablets discharged the drug far quicker and more certainly in-vitro when compared to the control tablets to the pure drug.
Conclusion: This experiment proves the application of PVP30 as a hydrophilic carrier in a solvent evaporation solid-dispersion method is an efficient approach to increase the solubility and dissolution rate of the poorly water-soluble amlodipine drug. The 1:4 optimization resulted in the drug being altered to a stable and amorphous form, thus a significantly better release profile. This method presents a good avenue towards the generation of novel oral dosage shapes of amlodipine that may confer improved bioavailability and dependable therapeutic results