Dapagliflozin Loaded Bilosomes Gel for Transdermal Delivery: Formulation, Optimization, Physicochemical...

Diabetes mellitus (Type 2, DM) is a metabolic disorder characterized by elevated blood glucose levels. Dapagliflozin (DZ) is a recently developed antidiabetic drug, but its oral use is challenged by permeability-limited absorption and first-pass metabolism, primarily via glucuronidation. The present study aims to formulate DZ-loaded bilosomes (BLS) gel for transdermal delivery to increase drug permeation and therapeutic efficacy. The DZ-BLS was formulated using the thin-film hydration method and optimized using BBD. Optimized DZ-BLS (DZ-BLS13) showed 124.2 nm of vesicle size (VS), 0.389 of PDI, 40.9 (negative) of zeta potential, and 90.76% of drug entrapment efficiency (EE). The DZ-BLS13 formulation was incorporated into chitosan gel and evaluated for various in vitro and in vivo studies. The optimized DZ-BLS13 gel formulation (DZ-BLS13G2) demonstrated favorable physicochemical properties, including an appropriate viscosity (764 ± 20.00 cP), good spreadability (228.33 ± 2.88%), and compatibility with the physiological pH (6.03 ± 0.23) of the skin. Additionally, the formulation demonstrated a sustained drug-release profile (95.17 ± 5.23%) for up to 24 h. Moreover, DZ-BLS13G2 exhibits significantly higher ex vivo rat skin permeation (1.69 ± 0.62-fold higher flux) than DZ conventional gel (DZ-G). Histopathology on excised rat skin revealed no sign of irritation. The pharmacokinetic study of DZ-BLS13G2 revealed improved bioavailability (1.88-fold and 1.48-fold) and prolonged plasma drug levels compared with DZ conventional gel and oral DZ-dispersion. Additionally, DZ-BLS13G2 exhibited significantly higher antidiabetic activity than DZ conventional gel and oral DZ-dispersion. From the findings, it can be concluded that BLS gel is a novel carrier for transdermal drug delivery to enhance therapeutic efficacy.