Dosage unit uniformity and dissolution testing of extended-release pharmaceutical products marketed in the U.S.

An international sampling study yielded 69 samples of extended-release prescription pharmaceuticals for legal sale in the U.S. Samples included 29 lots of innovator and 40 lots of generic solid oral extended-release drugs manufactured at 16 different facilities and containing 6 different active ingredients. Dosage unit uniformity and dissolution were tested for each lot. All samples met the relevant testing criteria for dosage unit uniformity and dissolution. There were no indications that manufacturer or region impacted a product's acceptability for use by patients. The variability of attributes was used to calculate a process performance index (Ppk) for each facility. Higher Ppk values suggest less variability relative to specification limits. Only two manufacturers fell below a 4-sigma manufacturing benchmark Ppk of 1.33 for dosage unit uniformity: a European manufacturer of a brand drug and an Asian manufacturer of a generic drug. Conversely, all but four manufacturers fell below a 4-sigma benchmark for the minimum Ppk across their product's dissolution timepoints: generic drug manufacturers in India (two), the U.S., and Canada. Compared to the immediate-release products of a previous study, Ppks were generally lower for extended-release products. A retrospective analysis found that manufacturers performing below median Ppks submitted more Field Alert Reports after the end of the sampling period.