Studies on the Microbial Degradation of Some preservatives used in pharmaceutical Preparation

A total of 439 bacterial, 7 2 mould and 23 yeast strains isolated from non- sterile pharmaceutical articles and from their manufacturing environment were screened for their ability to grow on nutrient agar media supple merited with various preservatives at concentrations com¬monly employed for the preservation of pharmaceutical preparations. The preservatives used are propylparaben, metliylparaben , cetrimide, phenylmercuric nitrate, chorocresol and chlorbutol.Microbial isolates showing; distinct resistance to any of the selected preservatives, were subjected to further screening to determine the. ability of these iso¬lates to utilize the indicated preservatives for growth in mineral salts media. The results obtained show that13 bacterial isolates (2.9%) were able to grow in the, presence of 0,05% chlorocreaol in nutrient agar; only one of them (7.6 %) , the isolate No . 439 iden¬tified as Pseudomonas aeruginosa , was able to utilize this preservative as a sole source of carbon and energy