Effect of compression pressure, preservative, and storage with potassium chloride on the microbiological quality of tablets formulated with Terminalia randii Gum (Combretaceae).

Gums are used as binders in tablets and also as emulsion stabilisers, suspending agents and thickeners in syrups. The need for other natural gums apart from the conventional gums to be employed as binding agents in tablets formulation led to this study. A gum obtained from the incised trunk of Terminalia randii (Combretaceae) was evaluated for the effect of compression pressure, methyl paraben preservative and storage with potassium chloride, on the microbial load of tablets formulated with the gum. The microbial load was determined by surface spread method on the processed gum at suitable dilutions, and tablets formulated from the gum at different compression pressures. The formulated tablets were evaluated for microbial load, also when stored in potassium chloride for 8 and 12 weeks with and without preservation with 1% Methyl Paraben. In each case the compressed tablets were incubated in 0.1% peptone water as control. The microbial load recorded reflected generally, reduction in microbial counts in tablets formulated with the gum as a binder both in terms of compression at different pressures and when the different compression pressures were associated with or without 1% methyl paraben in the presence of potassium chloride. Comparatively, the processed gum showed higher microbial load than the pressure compressed tablets. Besides the different compression pressures, duration of storage was also found to cause reduction of microbial load, particularly in the formulated tablets compressed with methyl paraben stored in potassium chloride such that after 8 weeks, the microbial load was zero. The studies showed that compression pressures and duration of storage caused marked reduction in microbial load of the tablets formulated with the processed gum of Terminalia randii as a binder.