Microbiological Assessment of Oral Liquid Formulations Manufactured in Dar-Es-Salaam, Tanzania

M P Kinyawa; M Justin-Temu; E F Lyamuya; C Makwaya

M P Kinyawa Faculty of Pharmacy, 'Faculty of Medicine, 3lnstitute of Public Health, Muhimbili University College of Health Sciences, P.O. Box 65005, University of Dar es Salaam, Tanzania.
M Justin-Temu Faculty of Pharmacy, 'Faculty of Medicine, 3lnstitute of Public Health, Muhimbili University College of Health Sciences, P.O. Box 65005, University of Dar es Salaam, Tanzania.
E F Lyamuya Faculty of Pharmacy, 'Faculty of Medicine, 3lnstitute of Public Health, Muhimbili University College of Health Sciences, P.O. Box 65005, University of Dar es Salaam, Tanzania.
C Makwaya Faculty of Pharmacy, 'Faculty of Medicine, 3lnstitute of Public Health, Muhimbili University College of Health Sciences, P.O. Box 65005, University of Dar es Salaam, Tanzania.

Abstract

The aim of the study was to determine the microbiological quality of locally manufactured oral liquid pharmaceutical preparations in Dar es Salaam. Seven hundred and twenty drug formulations comprising of 320 (44.4%) syrups and 400 (55.6%) mixtures collected from retail pharmacies and drug stores were analyzed for the total viable aerobic count by the plate count method. Microorganisms isolated from the samples were identified with use of routine microbiological and biochemical identification tests.
Results obtained revealed microbial growth in 49.0% of the mixtures and 42.8% of the syrup preparations, but the difference was not statistically significant (p0.05). Different organisms were identified from the two formulations and their distribution pattern was found to be significantly different. Gram-negative rods were isolated only from mixtures. Potential pathogens isolated, including Pseudomonas spp. and yeasts were found more in mixtures (10.5%) than in syrups (0.3%) and this difference was statistically significant (p<0.005). Mixtures of Magnesium trisilicate, Kaolin and Belladona, contained more potential pathogens compared to the rest of the mixtures. Water used during manufacturing of the formulations was considered to be the main source of contamination.
From these findings, strict criteria for issuing licenses for drug manufacturing in Tanzania are recommended, and adherence to Good Manufacturing Practice should be emphasized. The study findings provide baseline information, which may be of use in an attempt to improve the quality of pharmaceutical products and in setting up local standards in Tanzania.