Quality control of herbal medicines

The use of traditional and herbal medicines is gaining recognition globally. To safeguard the patient, there are legitimate demands that all medicines be safe, efficacious and of good quality. The required parameters for their quality evaluation include assessment for inorganic matter (dust), absence of adulteration, microbial load, identification and profile of contents and where possible quantitation of the active compound or marker compounds. Also of importance are heavy metals, pesticides and product stability. The mixture of portions of herbs in traditional medicines complicates the quality control tests of these preparations. The content profile becomes difficult to replicate from batch to batch, while quantification of the active compound(s) in such multi-component products would require prior processing to isolate and identify the chemical compounds. Keywords: herbal medicines quality control The East and Central African Journal of Pharmaceutical Sciences Vol. 8(2) 2005: 27-3

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

Liquid Chromatographic Separation of Isoniazid, Pyrazinamide and Rifampicin on a Reversed-Phase Silica Column

A gradient liquid chromatographic method which can separate isoniazid, pyrazinamide and rifampicin is described. A Hypersil C18, 5 mm, 250 mm x 4.6 mm internal diameter column was maintained at 40°C. The method was developed by systematic evaluation of the influence of the buffer concentration, column temperature and the mobile phase pH. The method proposed uses isocratic elution with potassium phosphate buffer (pH 6.0; 0.05 M) for 10 min, followed by linear gradient to potassium phosphate buffer (pH 6.0; 0.05 M)-methanol (40:60, v/v) in 5 min, isocratic elution at the same composition for a further 15 min and then linear gradient back to potassium phosphate buffer (pH 6.0; 0.05 M) in 5 min. The flow-rate was 1 ml/min and UV detection was at 254 nm. The method was validated and it has been used for routine analysis of tablets containing isoniazid, pyrazinamide and rifampicin. Analysis time is 35 minutes. (E & C Afr Jnl Pharm Sci: 2002 5(1): 8-14

Constituents of the stem bark of Dombeya rotundifolia Hochst

Two compounds isolated from Dombeya rotundifolia chloroform stem bark extract were identified as lupeol and β-sitosterol using infra red, nuclear magnetic resonance and mass spectrometry. The East and Central African Journal of Pharmaceutical Sciences Vol. 8(2) 2005: 40-4

Traditional herbal medicine in national healthcare in Kenya

Herbal medicine is becoming increasingly popular all over the world. There are studies suggesting that herbal therapies can be effective in treating certain conditions. This has been confirmed by the classic randomized, placebo-controlled, double blind well-designed clinical trials. With reliable information on herbal medicine, it is easier to integrate these therapies with the mainstream medicine. It is unlikely that patients will completely abandon use of era I medical interventions but rather in a more pragmatic manner will choose to integrate other interventions as a part of their overall armamentarium of medical interventions. Can herbal medicine be integrated with mainstream medicine in Kenya and what are the challenges? This paper discusses these and other questions in respect of herbal medicine. The East and Central African Journal of Pharmaceutical Sciences Vol. 8(2) 2005: 22-2

Anti-Inflammatory and Anti-Diarrhoeal Activities of a Steroidal Indoxyl

The anti-inflammatory and antidiarrhoeal activities of 3β-Hydroxy-16, 17-seco-16-nor-5-androsten-15-(2-indoxyliden)-17-oic acid (I) are reported. After intraperitoneal administration, compound (I) gave an ED50 of 9.5 mg/kg using the carrageenan induced rat paw oedema anti-inflammatory assay method. Indomethacin had an ED50 of 5.8 mg/kg in this assay. Compound (I) and indomethacin caused comparable and dose-dependent varying degrees of delay in diarrhoea and also significantly reduced net colonic water flux into the colon of rats induced by castor oil. Key words: Steroidal Indoxyl, Anti-Inflammatory, Antidiarrhoeal. East and Central African Journal of Pharmaceutical Sciences Vol.6(2) 2003: 26-2

Antimicrobial Activity and Bioactive Constituents of Alectra sessiliflora (Vahl) Kuntze Methanol Extract

Alectra sessiliflora (Vahl) Kuntze (Scrophulariaceae) is traditionally used in western Kenya in the management of microbial infections. The water, chloroform and methanol extracts of A. sessiliflora whole plant exhibited antimicrobial activity against a range of bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Shigella dysenteriae and Bacillus pumilus) and fungi (Candida albicans, Aspergillus niger and Cryptococcus neoformans). The methanol extract exhibited the highest activity with minimum inhibitory concentration (MIC) of 3.13-6.25 and 3.13-12.5 mg/ml for bacteria and fungi, respectively. Chromatographic fractionation of the methanol extract through non-polar D101 macroporous resin beads yielded three bioactive compounds: two phenolic compounds, p-coumaric acid and 3,4-dihydroxybenzoic acid, and a flavonoid, luteolin. The compounds exhibited appreciable activities against tested bacteria and fungi with MIC values ranging from 0.13 to 0.25 and 0.13 to 0.50 mg/ml, respectively. These constituents might be responsible either individually or collectively for the traditional use of the plant to manage bacterial and fungal ailments. The in vitro antimicrobial activity and isolation of bioactive compounds from this plant are being reported for the first time.Key words: Alectra sessiliflora, ethnomedicine, antibacterial and antifungal activity, bioactive constituent

Quality of Amoxycillin Preparations on the Kenyan Market

East and Central African Journal of Pharmaceutical Sciences Vol.6(3) 2003: 57-6

Phytosterols from the stem bark of Combretum fragrans F. Hoffm

Two sterols, β-sitosterol and stigmasterol, were isolated from the stem bark of Combretum fragrans. The identity of these compounds was established by spectral analysis

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