Nano micelle mediated In-Vitro release kinetics of two Biopharmaceutical Classification System (BCS) class II drugs with varying hydrophobicity

This study investigates the in-vitro release kinetics of two BCS Class-II hydrophobic drugs, Irbesartan (IRB) and Lamotrigine (LAM), from nano micellar systems composed of Pluronic^® (P84, F108) and Tetronic^® (T1307) copolymers. Prior to release studies, drug solubilization efficiency and micelle size were evaluated using UV–Visible spectroscopy and Dynamic Light Scattering, both in the presence and absence of NaCl. Among the tested formulations, Pluronic^® P84 demonstrated superior solubilization for both drugs, enhancing IRB and LAM solubility by ~ 3.6/2.3 times compared to F108 and ~ 1.6/1.9 times compared to T1307 in 1 M NaCl. Additionally, P84 formed smaller (~ 15 to 16.5 nm), more stable micelles, indicating its potential for effective drug delivery. Drug release profiles were assessed over 24 h and fitted to various kinetic models-zero-order, first-order, Higuchi, Hixson-Crowell and Korsmeyer-Peppas-to elucidate the dominant release mechanisms. For IRB, release from aqueous and 1% P84 micellar systems followed the Hixson-Crowell model (99.8% and 96.7%), indicating surface area-dependent dissolution. Formulations with 1% P84 + 1 M NaCl (87.8%) and 1% T1307 (90.1%) adhered to the Higuchi model, suggesting diffusion-controlled release. The Korsmeyer-Peppas model best described IRB release from 1% T1307 + 1 M NaCl (82.0%), indicating combined diffusion and erosion mechanisms. In contrast, LAM release from all systems followed the Korsmeyer-Peppas model, reflecting a consistent anomalous transport behaviour. Overall, these results demonstrate the significant influence of micellar composition and ionic conditions on solubilization and drug release, providing guidance for the rational design of micellar drug delivery systems.

Graphical Abstract