Development and Evaluation of a Baicalin-Loaded Phytosomal Transdermal Patch for Type 2 Diabetes Mellitus

Type 2 diabetes management remains challenging because of low bioavailability, side effects, and poor compliance with oral therapies. Transdermal delivery methods offer a non-invasive therapeutic approach with sustained delivery, which avoids first-pass metabolism.

A total of 207 different phytochemicals were virtually screened using i-dock against the diabetic target, PPAR-γ. Subsequently, three matrix-type transdermal patches were developed: a patch containing pure baicalin, a standard patch containing metformin, and a baicalin-loaded phytosomal patch. Phytosomes loaded with baicalin were optimized by using Central Composite Design and evaluated for their physicochemical properties, drug content, physical strength, in vitro, and ex vivo studies. In vivo antidiabetic efficacy was also studied in diabetic Wistar rats over 21 days, followed by a comparison of all formulations, including histopathological analysis of pancreatic tissue.

Molecular docking studies showed promising results; baicalin has a high binding affinity for PPAR-γ (-9.8 kcal/mol). The optimized phytosomal patch confirmed a uniform drug content (91.4 ± 0.12 %) and showed sustained release over 12 hours. The ex vivo permeation study showed a significantly higher skin flux for the phytosomal patch (83.6%). In vivo studies confirmed that baicalin-loaded phytosomal patches showed significant blood glucose reductions (223 ± 0.32 to 96 ± 0.38 levels by Day 21), a comparable efficacy to standard metformin patches (224 ± 0.37mg/dL to 94 ± 0.34 mg/dL by Day 21).

The enhanced skin permeation, penetration, and sustained-release exhibited by the phytosomal transdermal patch can be explained by the phospholipid-based shell structure, leading to better affinity with the skin, facilitating retention of the drug. The comparable glycemic control observed with metformin indicates that baicalin-loaded phytosomal transder-mal patches can achieve effective therapeutic concentrations via transdermal delivery, which is corroborated across two studies. These observations are consistent with previous literature documenting improved solubility and bioavailability of plant-derived actives utilizing phyto-some-based systems, which have applicability for chronic metabolic diseases such as T2DM.

The developed phytosomal transdermal patch showed sustained release, better permeation, and potent antidiabetic activity; thus, it offers an alternative to conventional T2DM therapies.