THE EFFECT OF POLYANILINE ON THE CHARACTERIZATION OF ALGINATE/CARRAGEENAN/POLYANILINE FILM LOADED WITH LOVASTATIN

Abstract

Lovastatin (Lov), a potent inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, has limited clinical utility because of its poor aqueous solubility and suboptimal pharmacokinetics, characterized by low oral bioavailability (<5%) and a short elimination half-life. To overcome these limitations, a novel pH-responsive drug delivery system was developed by integrating the conductive polymer polyaniline (PANi) into a natural biopolymer matrix of sodium alginate (Alg) and κ-carrageenan (Carr). A series of Lov-loaded alginate/carrageenan/polyaniline/lovastatin (ACPL) biocomposite films containing different PANi content (3–15% w/w) were prepared by in situ oxidative polymerization and solvent casting. Structural and thermal characterization through Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy, and differential scanning calorimetry confirmed that lovastatin was successfully stabilized within the ternary matrix through an intermolecular network of hydrogen bonding and van der Waals interactions, effectively preserving its chemical integrity while disrupting its crystalline lattice. Morphological analysis revealed that the incorporation of PANi significantly refined the drug's particle size from a micro-scale (10–60 μm) to a sub-micron dispersion (0.05–0.20 μm), with the ACPL5–alginate/carrageenan/polyaniline/lovastatin formulation, incorporating 5% polyaniline relative to the alginate/carrageenan polymer matrix, exhibiting the most homogeneous distribution. In vitro release studies demonstrated superior site-specific performance; all formulations provided robust gastric protection at pH 2.0 (release <10%), while ACPL5 achieved a near-quantitative sustained release of 97.53% at pH 7.4 within 30 h. These results demonstrate that the Alg/Carr/PANi composite, particularly at a 5% PANi loading, is a highly effective vehicle for modulating release kinetics and potentially enhancing the therapeutic efficacy of hydrophobic statins.