Microbiological Quality of some Expired Drugs in Sokoto Metropolis, Nigeria

Abstract

Twenty eight samples of expired drugs were obtained from different medical stores including Sokoto State Medical Store in Sokoto Metropolis. The drugs included paracetamol, vitamin C (Ascorbic acid), Phenergan (promethazine), Chloroquine (A 4–aminoquinoline acid), flagyl (metronidazole), folic acid (Pteroylglutamic acid), tablets and vitamin A injection (Retinol). The tablets were ground into powder using sterile pestle and mortar. Powder of each tablet (0.2g) and 0.2ml vitamin A injection was dispensed into 9ml sterile nutrient broth. After incubation for 24 hours, a loopful from the growth was subcultured into nutrient agar and malt extract agar plates. The nutrient agar plates were incubated at 37^oC for 24 hours and the Malt Extract plates were incubated at 26^oC for 3-7 days After incubation, the organisms were identified using a combination of microscopy and biochemical tests. For each drug, the procedure was repeated four times. The frequency of occurrence of each organism was determined and found to be: Aspergillus niger 28(60%); Aspergillus flavus 28(32%); Penicillium spp. 28(14%); Scopulariopsis spp. 28(7%); Neurospora spp. 28(7%); Mucor sp. 28(4%); Enterococcus avium 28(35%); Staphylococcus aureus 28(29%); Enteococcus gallinarum 28(25%); Staphylococcus epidermidi, 28(17%); Enterococcus durans 28(14%) and Staphylococcus saccharolyticus 28(14%). The results demonstrated the involvement of pathogenic microorganisms; therefore, expired drugs should not be consumed no matter how neat they may appear.