A stability indicating high performance liquid chromatographic assay of isradipine in pharmaceutical preparations

A high performance liquid chromatographic procedure has been developed for assay of isradipine in bulk form and tablet and capsule pharmaceutical preparations. The separation is achieved within 20 min on an octadecylsilane column at ambient temperature with a mobile phase of 60:40 v/v methanol - water, a flow rate of 1 mL/min, and detection at 325 nm. Degradation studies showed no peak interference between isradipine and degradation products. It was also determined that the excipients in the commercial tablet and capsule preparations did not interfere with the assay. The method was linear in the range 10-60 mu g/mL with accuracy and precision in the 0.40 - 1.53% range.