Design and Evaluation of a Novel Gas Formation-Based Multiple-Unit Gastro-Retentive Floating Drug Delivery System for Quetiapine Fumarate

Purpose: To develop a gastro-retentive formulation of quetiapine fumarate in the form of floating minitablets.
Methods: The system consisted of core units prepared by direct compression process, which were coated with three successive layers, namely, an inner seal coat, effervescent layer and an outer polymeric layer of polymethacrylates.
Results: Mini-tablets coated with Eudragit RS 30D (5, 7.5 and 10%) released ≤ 85% of the drug after 12 h, while those coated with Eudragit RL 30D (5, 7.5 and 10%) released ≥ 85% drug within the same period. Drug release kinetic studies showed that drug diffusion fitted best to zero order and Higuchi models, indicating that drug release was anomalous non-Fickian transport. In vivo gastric residence time results indicate that the units remained in the stomach for about 6 h (n = 3). There was no significant change in dissolution profiles before and after storage at 40°C and 75% RH for 6 months.
Conclusion: The developed floating mini-tablets of quetiapine fumarate exhibit prolonged release for ≥12 h, and thus may improve bioavailability and minimize fluctuations in plasma drug concentrations.

Keywords
Mini-tablets; Floating delivery system; Effervescence; Polymeric membrane; Controlled release; Quetiapine fumarate