Liquid chromatographic assays for barbiturate injections.

Precise, rugged, stability-indicating HPLC assays were developed for phenobarbital, pentobarbital, and secobarbital sodium injections. Degradation products of the three barbiturates were prepared and chromatographed to demonstrate method specificity. The degradation products were also used to demonstrate specificity of official GC methods for pentobarbital and secobarbital sodium capsules. The acetylurea degradation products of pentobarbital and secobarbital were characterized following the separation of their diastereoisomers by HPLC.