Hydrolysis and determination of meprobamate

Most pharmacopoeial methods for meprobamate are based on acid hydrolysis, followed by determination of the ammonia formed. In order to find optimum conditions the hydrolysis was studied with the aid of TLC. Various types and concentrations of acid were tested. Refluxing with 25% (wt/vol) HCl for two hours proved to be sufficient to achieve complete hydrolysis (99.4 +/- 1%). This method is less time-consuming than that of the European Pharmacopoeia and the hydrolysate does not turn brown as is the case with high concentrations of H2SO4.