The presence of microorganisms in some common excipients used in tablet formulation.

Strict measure on the need to control microbial contamination in the formulation of solid dosage forms such as tablets and capsules are not usually in place as is done in other pharmaceutical preparations. The presence of microorganisms in some common excipients such as starch and lactose powders, and distilled water used in tablet formulation was investigated in this study. Organisms isolated were Geotrichuim and Aspergillus spp as well as two strains of Staphylococcus aureus. Lactose tablets were further formulated using 5% starch as binder. Some of the isolated organisms were, in turn, inoculated into these tablets and stored over a period of several weeks. The physical properties of these tablets were determined at various time intervals. Marked increases in the disintegration times of these tablets were observed, while there was a decrease in the hardness property for both the fungi and bacteria. These observed effects have serious implications in the overall bioavailability of drugs such as tablets formulated from contaminated excipients.