Sulfadimidine is a sulfonamide antibacterial.The medicated premix is supplied as powdered form and administered orally after mixing with animal feed. The sulfadimidine analytical method described in United States Pharmacopoeia 23 cannot be used to carry out the stability study because of its lack of specificity for different degradation products. Therefore, a high-performance liquid chromatography method was developed to assay sulfadimidine. Suspensions of nonparenchymal cells did not metabolize sulfadimidine, sulfanilamide, or p-aminobenzoic acid during 4 hr, although such suspensions acted upon isoniazid to some degree. It was concluded that parenchymal rat liver cells may metabolize (acetylate) all four drugs tested, whereas nonparenchymal cells metabolize only isoniazid to any considerable extent.
-O657.gif)