Bioequivalency of Two Brands of Cephalothin Sodium

Abstract In order to assess the bioequivalency of two USA commercially available brands of cephalothin sodium, neutral, USP, a double-blind, single-dose, human crossover study was conducted. Serum and urinary samples were tested by HPLC assay, and pharmacokinetic parameters were determined by computer analysis. The results revealed that both products are bioequivalent, and support a submission to the FDA for a claim of "aqueous bioequivalency" of the new Seffin™ (Glaxo) brand vs. the standard. Hospital cost-containment programs, such as the recent Diagnostic Related Group (DRG) legislation, necessitates that Pharmacy & Therapeutic Committees evaluate competitive brands of identical drugs in order to realize cost savings but without sacrificing quality. Where generic equivalents are concerned, the major basis of comparison rests on clinical pharmacokinetic studies. Cephalothin sodium for injection, USP (Neutral) has been available in the USA since 1975, but only as a single source product (Keflin®/ Lilly). An equivalent produced by Glaxo (Seffin®) has been marketed in 19 countries for over a decade. The Glaxo product is now available for marketing in the U.S.A. by Glaxo Inc. under the same tradename 'Seffin™'. The purpose of this double-blind, single-dose, human crossover study was to compare the pharmacokinetic characteristics and bioequivalency of both cephalothin products.