Quality Attributes and In Vitro Bioequivalence of Amlodipine (5 mg) Tablets in Ica, Peru

Dissolution studies have evolved from quality control testing to being an indicator of biopharmaceutical performance and an alternative to in vivo bioequivalence and interchangeability studies in clinical practice. The critical quality attributes and in vitro bioequivalence of two generic formulations of amlodipine (5-mg tablets, A and B) were compared to the reference (Ref) drug. Amlodipine tablets available in Ica, Peru belong to class 1. The study evaluated weight, hardness, friability, and content of the tablets. USP apparatus 2 was used with 900 mL of dissolution medium at pH 1.2, 4.5, and 6.8. 5 (100 rpm, 37 ± 0.5 °C). Samples (5 mL) were withdrawn at 5, 10, 15, 20, 25, 30, 45, and 60 min and analyzed at 239 nm on a spectrophotometer. The dissolution percentages at pH 4.5 and 6.8 were less than 85% at 30 min for all three products; at pH 1.2, more than 85% was released in less than 15 min (Ref: 101.6%; A: 98.5%, B: 89.9%). The similarity factors were 51.2–64.3; dissolution efficiency was 84.5–96.5%, and mean dissolution time was 4.5–12.4 min. According to these parameters, generic formulations A and B demonstrated in vitro bioequivalence to the reference drug.