A comparative study of the quantitative analysis of barbiturates and related drugs in pharmaceutical formulations by nuclear magnetic resonance and high pressure liquid chromatography

Barbiturates, a common class of prescription drugs, are usually analysed for quality control by means of high pressure liquid chromatography (HPLC) which requires a pure standard of the drug for preparation of a standard curve. We have used nuclear magnetic resonance (NMR) to analyse the prescription drugs amobarbital, secobarbital, phenobarbital, pentobarbital, phenytoin and glutethimide using a single internal standard (3 - trimethylsilyl - 1 -propanesulfonic acid) and have compared this method with the HPLC technique. We found that both techniques are equally good for the quantitative analysis of barbiturates in tablets and capsules. Statistical analysis showed that there is no significant difference in the results obtained by using HPLC or NMR. NMR analysis was much faster than HPLC