Rapid dissolving microneedle patch integrated with benidipine-loaded nanotransfersomes for transdermal drug delivery: optimization, characterizations, and preclinical bioavailability assessment

Benidipine hydrochloride (BEN) is widely prescribed for managing hypertension; however, its clinical efficacy is limited by poor oral bioavailability. This study introduces an innovative delivery approach, incorporating BEN-loaded nanotransfersomes (BEN-TF) into a rapid dissolving microneedles (DMNs) patch for transdermal administration. The nanotransfersomal formulation was optimised via a Box-Behnken design following preparation using a thin-film hydration method. The optimised formulation exhibited favourable characteristics, including a vesicle size of 124.9 ± 1.49 nm, high entrapment efficiency (98.12 ± 0.18%), and transdermal flux of 9.74 ± 0.53 μg/cm²/hr. DSC, ATR-FTIR, and XRD analyses confirmed the amorphous state of BEN. Imaging via FESEM and HRTEM demonstrated spherical, uniform nanosized vesicles. Confocal microscopy revealed deep skin penetration. The integration of BEN-TF into DMNs (BEN-TF-DMNs) resulted in efficient skin insertion, rapid dissolution, and good mechanical strength. Ex-vivo results indicated superior permeation compared to BEN-TF or BEN-DMNs alone, while the in-vivo study confirmed improved bioavailability versus both oral tablets and BEN-DMNs. This hybrid delivery platform offers a promising strategy for improving the systemic delivery of BEN.