Comparative microbial contamination levels in wet granulation and direct compression methods of tablet production

Raw materials used for tablet production were assessed for their microbiological quality. Tablets were produced by wet granulation and direct compression methods and assessed for compliance with B.P. specifications. Samples from the production stages in the two tabletting processes were assessed for microbial levels and for absence from designated microbial species- E.coli, Ps.aeruginosa, S.aureus and salmonella species. The effect of the microbial levels of the raw materials and the formulation technology on the microbial levels of the produced tablets were also investigated. Results indicated that the microbial levels of the tablets were influenced by the microbial quality of the starting raw materials, the production environment and the method of production. Generally, tablets produced by direct compression method gave lower microbial levels than those of the wet granulation method. The compaction process exert lethal effect on the survival of microorganisms.