Development and Validation of a Liquid Chromatographic Method for the Simultaneous Analysis of Six Protease Inhibitors Using a Polymer Column

A liquid chromatographic method for the simultaneous determination of six human immunodeficiency virus (HIV) protease inhibitors, indinavir, saquinavir, ritonavir, amprenavir, nelfinavir and lopinavir, was developed and validated. Optimal separation was achieved on a PLRP-S 100 Å, 250 x 4.6 mm I.D. column maintained at 60 °C, a mobile phase consisting of tetrahydrofuran-potassium phosphate buffer (0.1M, pH 5.0)-tetrabutylammonium hydrogen sulphate (0.1M, pH 5.0)-water(35:30:10:25 %v/v) at a flow rate of 1.0 ml/min, with ultraviolet detection at 254 nm. The method was found to be linear over the ranges investigated with r2 values of 0.9997-0.9915 for the six drugs. The limit of quantitation for the six drugs was 0.16 to 5.12 μg, while the limit of detection was 0.08 to 2.12 μg. The intra-day and interday precision was within the ranges of 0.39 to 1.14% and 0.55 to 1.46%, respectively

Influence of manufacturing practices on quality of pharmaceutical products manufactured in Kenya

Objective: To establish the quality of pharmaceutical products manufactured by the respective industries in Kenya and determine the effect of manufacturing practices on the quality of these products. Design: Cross-sectional study. Setting: Industries examined are in Nairobi, Kenya. Laboratory analysis was carried out using available facilities at Kenya Medical Research Institute and University of Nairobi, Faculty of Pharmacy. Interventions: Structured Questionnaires were administered to examine how the code of good manufacturing practices has been used in the production of each pharmaceutical product by respective companies. Questionnaires designed to evaluate the distribution and carry out limited post-market surveillance study were administered to community pharmacy outlets. Drugs were sampled and analyzed for their quality according to the respective monographs. Main Outcome Measures: The questionnaires administered to the industry included the source of raw materials, quarantine procedure before and after manufacture, manufacturing procedure, quality audit, quality assurance procedure, equipment, and staff. That administered to the pharmacy outlet included availability, affordability and acceptability of locally manufactured pharmaceutical products. Quality analysis of products involved the establishment of the chemical content, dissolution profile, friability, uniformity of weight and identity. For antibiotic suspensions the stability after reconstitution was also determined. Results: There were 15 respondents and two non-respondents from the industry and six out of nine respondents from the pharmacy outlets. The ratio of qualified staff to product range produced seemed to influence product quality. Industries producing several products with only limited number of pharmaceutical staff had more products failing to comply with pharmacopoeia specifications compared to those producing only few products. Nevertheless, all companies are well equipped with quality control equipment, in accordance with type of product manufactured. Private pharmacies stocked few of the locally manufactured products. The reason, they said, was due to low doctor and/or patient acceptance. Compliance with quality specifications as set out in respective monographs was overall 76%. Conclusion: Although the local pharmaceutical industries have adopted good manufacturing practices leading to many good quality products currently in commerce, these manufacturing practices are not comprehensive and measures need to be taken to continue improving them. East African Medical Journal Vol.81(6) 2004: 287-29

Antiglycation and antioxidant properties of Momordica charantia

The accumulation of advanced glycation endproducts (AGEs) and oxidative stress underlie the pathogenesis of diabetic complications. In many developing countries, diabetes treatment is unaffordable, and plants such as bitter gourd (or bitter melon; Momordica charantia) are used as traditional remedies because they exhibit hypoglycaemic properties. This study compared the antiglycation and antioxidant properties of aqueous extracts of M. charantia pulp (MCP), flesh (MCF) and charantin in vitro. Lysozyme was mixed with methylglyoxal and 0–15 mg/ml of M. charantia extracts in a pH 7.4 buffer and incubated at 37°C for 3 days. Crosslinked AGEs were assessed using gel electrophoresis, and the carboxymethyllysine (CML) content was analyzed by enzyme-linked immunosorbent assays. The antioxidant activities of the extracts were evaluated using assays to assess DPPH (1,1-diphenyl-2-picryl-hydrazyl) and hydroxyl radical scavenging activities, metal-chelating activity and reducing power of the extracts. The phenolic, flavonol and flavonoid content of the extracts were also determined. All extracts inhibited the formation of crosslinked AGEs and CML in a dose-dependent manner, with MCF being the most potent. The antioxidant activity of MCF was higher than that of MCP, but MCP showed the highest metal-chelating activity. MCF had the highest phenolic and flavonoid contents, whereas MCP had the highest flavonol content. M. charantia has hypoglycaemic effects, but this study shows that M. charantia extracts are also capable of preventing AGE formation in vitro. This activity may be due to the antioxidant properties, particularly the total phenolic content of the extracts. Thus, the use of M. charantia deserves more attention, as it may not only reduce hyperglycaemia but also protect against the build-up of tissue AGEs and reduce oxidative stress in patients with diabetes