Biotin dissolution from pharmaceutical dosage forms using an automated HPLC system

A novel, rapid, accurate, and sensitive automated high-performance liquid chromatographic assay was developed to determine biotin (BI) in pharmaceutical dosage forms and to follow its dissolution pattern. An efficient separation of BI was performed using a stainless steel Supelcosil LC-18 column (25 cm x 4.6 mm; 5 mum particle size) preceded by a Sentry guard column. The mobile phase consisted of an 80% aqueous solution (pH 2.5 adjusted with phosphoric acid) containing 20% acetonitrile delivered at a flow rate of 1.5 mL/min. The compound of interest was detected using a photodiode array detector at 190 nm. Under these conditions, the assay run time was 6 min since the retention time of BI was 3.8 +/- 0.2 min. The detector response was linear for BI in alkaline solution (r > 0.999) in the range of 0.01-2.00 mug/mL. The detection and the quantification limits for BI were 0.005 and 0.01 mug/mL, respectively. The dissolution data showed RSD% of 3.6-12.7% for all BI determined concentrations. No interferences were observed from the tablet's excipients. The drug content in each tablet ranged from 100 to 102.5%. The dissolution study of BIOTIN(R) tablets revealed that BI in USP media (pH 1.2) showed no dissolution up to 3 hr. However, a first order release kinetic, with dissolution T-50% of 14 +/- 1.3 min, was observed in USP media (pH 7.4).