Mucoadhesive lyophilized wafers loaded with nano-spanlastic felodipine formulation: development and characterization

Felodipine (FDP) is used to treat hypertension and angina pectoris. FDP has an oral bioavailability of approximately 15% in humans, primarily due to its poor water solubility and extensive first-pass metabolism in the liver and gut wall. The study aimed to develop and evaluate a lyophilized buccal wafer containing felodipine-loaded nano-spanlastics to enhance solubility, permeability, and therapeutic efficacy. FDP-loaded nano-Spanlastics (FDP-SL) using a 2³ factorial design. The developed SL formulations were physiochemically characterized. In vitro permeation studies assessed trans-buccal delivery, while FDP-SL7 was incorporated into CMC wafers for mucoadhesive application. In vivo investigations evaluated the effects of the formulations. Histopathological assessment further contrasted the protective effects of the SL-7 wafer with those of Plendil on cardiac tissues. DLS studies of the modified SL-7 indicated particle size, PDI, and zeta potential values, followed by the assessment of EE (95.38 ± 0.96%), deformability index (12.46 ± 0.46 g), flux (28.51 ± 0.21 g/cm²/h), and stability, collectively demonstrating a 4.72-fold enhancement. The drug release data indicates Q24h values of 63-66% for SL formulations compared to the quick release of the suspension. Additionally, the ex vivo permeability results demonstrate that SL7 exhibits a flux of 28.51 ± 0.21 µg/cm²/hr, reflecting a 4.72-fold boost over the drug suspension. In vivo studies showed significant improvements in blood pressure. Encapsulating FDP in Tween 80-based SL and delivering it via mucoadhesive buccal wafers significantly enhances its bioavailability and therapeutic efficacy. This non-invasive approach offers a promising strategy for improved hypertension management.