Journal of Bioequivalence & Bioavailability

Abstract

Bioequivalence of Two Different Rivastigmine Hard Capsule Formulations of Two Different Strengths (1.5 mg and 6 mg) in Indian Healthy Human Adult Male Volunteers

Garg M, Naidu R, Iyer K and Jadhav R

Rivastigmine, a butyl- and acetylcholinesterase inhibitor, is approved for symptomatic treatment of Alzheimer's disease (AD). The aim of these studies was to determine the bioequivalence of test and reference formulations of Rivastigmine 1.5 mg and 6 mg Hard Capsule. Both studies were single dose, randomized, 2-period, 2-sequence, laboratory-blinded, crossover design. Rivastigmine 1.5 mg Hard Capsule study was conducted in 36 healthy adult Indian male volunteers under fasting conditions with a washout period of 5 days and Rivastigmine 6 mg Hard Capsule study was conducted in 40 healthy adult Indian male volunteers under fed conditions with a washout period of 7 days. For 1.5 mg study, blood samples for pharmacokinetic profiling were taken post-dose up to 10 h. For 6 mg study, blood samples for pharmacokinetic profiling were taken post-dose up to 12 h. Safety was evaluated through the assessment of adverse events, and laboratory tests. Plasma concentrations of Rivastigmine were determined with a validated LC-MS/MS method. Bioequivalence between the products was determined by calculating 90% confidence intervals (90% CI) for the ratio of Cmax, AUC0-t and AUC0-∞ values for the test and reference products, using logarithmic transformed data. The 90% CI of Rivastigmine were 89.63-113.68, 86.91-103.87 and 87.30-103.80 for Cmax, AUC0-t and AUC0-∞ respectively for Rivastigmine 1.5 mg Hard Capsule study. The 90% CI of Rivastigmine were 93.08-118.44, 94.14-104.46 and 93.77-104.12 for Cmax, AUC0-t and AUC0-∞ respectively for Rivastigmine 6 mg Hard Capsule study. Since the 90% CI for Cmax and AUC0-t were within the 80.00-125.00% interval, it was concluded that the test and reference formulations of Rivastigmine 1.5 mg and 6 mg Hard Capsule were bioequivalent in their rate and extent of absorption.