Formulation And In-Vitro Characterization of Co-Loaded Kaempferol and Quercetin Polymeric Transdermal Patches for Enhanced Glucose Uptake Activity

Transdermaldrugdeliverysystems(TDDS)haveemergedasasignificanttherapeuticalternative toconventionaloralhypoglycemicagents, primarilyduetotheir abilityto bypasshepatic first-pass metabolism, maintain stable plasma drug concentrations, and eliminate gastrointestinal adverse effects. Given the therapeutic efficacy of natural antioxidants in long-term metabolic control, integrating isolatedbioactivecompoundsintotransdermalmatricesoffersacontrolled systemicapproachforbloodglucoseregulation.Theprimaryobjectiveofthisinvestigationwas to formulate, systematically characterize, and evaluate the biopharmaceutical performance of matrix-type transdermal patches co-loaded with the isolated flavonoids Kaempferol and Quercetin,utilizingoptimizedpolymericblendsforenhancedin-vitroglucoseuptake.Thematrix-typetransdermalpatches(designatedasFormulationsF1throughF3)were fabricated using the solventcastingtechnique.HydroxypropylMethylcellulose(HPMCE5)served asthe structural film-forming polymer matrix. Polyethylene Glycol-400 (PEG-400) was incorporated as the plasticizertoimpart structuralflexibility, whilePropyleneGlycolwasutilized as the chemical permeation enhancer to optimize patch diffusivity. The physical compatibility between the active phytoconstituents and the polymeric excipients was rigorously evaluated and verified using Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) spectroscopy. Physicochemicalcharacterizationofthefabricated filmswascarriedout bymeasuringthickness, weight variation, folding endurance, and tensile strength. In-vitro drug release profiles were monitored over a 24-hour period across a Franz diffusion cell setup. Biocompatibility and functional antidiabetic efficacy were established via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide(MTT)cytotoxicityassaysandquantitativeglucoseuptakestudies using Human Hepatoma (HepG2) cell lines, evaluated via the Dinitrosalicylic Acid (DNS) spectrophotometric method.The physicochemical evaluation demonstrated that the optimized polymeric transdermal films possessed excellent mechanical integrity, exhibiting a thickness range0.21 ± 0.01 mm to 0.25 ± 0.02 mm and an exceptional tensile strength of 4.08 MPa, significantly exceedingthestandardbenchmark valueof2.54 MPa. Thefolding enduranceprofile remained optimal (>170), indicating superb elasticity and structural resistance to mechanical stress.In-vitroskinpermeationmodelsfollowedacontrolled,matrix-drivenreleasepatternover24 hours. Formulation F3 demonstrated the highest cumulative drug release, achieving a maximum release percentage 95.60%for Kaempferoland 83.03% for Quercetin. The in-vitrocelllinemodelsconfirmed the safetyandpharmacodynamicpotentialofthepatchmatrix. The MTT cytotoxicityassay on HepG2 cell lines revealed an exceptional cell viabilityrate of 97.59%, verifying the formulations as highly biocompatibleandnon-toxic.Furthermore, the functional pharmacodynamic analysis demonstrated a profound increase in cellular glucose utilization, as evidenced by a substantial decline in the remaining external glucose concentrations froman initialcontrol levelof 0.10 mg/mLdownto0.04mg/mL}inthepatch-treated domain.The experimental findings conclusively demonstrate that the co-loaded Kaempferol and Quercetin matrix-type transdermal patches successfully maintain structural integrity, deliver uniform sustained drug release over extended periods, and significantly stimulate peripheral glucose uptake in-vitro. This deliveryplatformrepresents a highly stable, safe, and efficacious therapeutic modality for non-invasive, chronic diabetic management.