An optimized method for the simultaneous determination of vitamins B1, B6, B12 in multivitamin tablets by high performance liquid chromatography.

A simple, precise, rapid and selective HPLC-RP method has been developed for the simultaneous determination of thiamine hydrochloride (B(1)) 150 mg, pyridoxine hydrochloride (B(6)) 150 mg, and hydroxocobalamine chloride (B(12)) 0.150 mg in multivitamin tablets. The method uses a Hypersil-BDS C(18) reversed phase column and gradient elution. The aqueous mobile phase contained 0.015% triethylamine adjusted to pH 2.7 with 1 N sulfuric acid and acetonitrile. Separation and quantitation was achieved by changing the proportion of the system linearly with a time-schedule programme. Detection was carried out using a dual-beam UV detector set at 280, 350 nm. Good linearity was observed between the concentration of the analytes and peak area (r=0.9999, 0.9998). Sample preparation was relatively simple whereas excipients present in the dosage forms did not interfere with the peaks of interest. Recovery of the compound from the B(1), B(6), B(12) was quantitative.