Stabilizing effect of chitosan-poly vinyl alcohol complex on simvastatin loaded nanoformulation

Biopolymers are attractive new and general means of presenting more stable drug delivery system. This is accomplished by encapsulation of polymers to respective drug molecules which offer formation of bonds between them.  In this work, chitosan-coated simvastatin nanoformulation was formulated using a method named solvent evaporation technique, and various stability studies were performed. The steadiness of preparation was evaluated by accelerated stability method and forced degradation method. High-performance thin-layer chromatography (HPTLC) was utilized to detect the degradant present in formulation after subjecting it in different stress condition. Simulated annealing process for the prediction of nanoformulation stability was also performed. The accelerated stability study was performed at three altered temperature conditions, (i.e.) accelerated temperature (40 ± 2 °C/75 ± 5% RH), room temperature (25 ± 2 °C/60%) ± 5% RH, and freezing temperature (4°C) and change in drug content, solubility, % cumulative drug release, moisture content and molecular weight were calculated. Standard sample and nanoformulation were exposed to different stress conditions (thermal, base, acid, and light). Finally, the percentage of decomposition was calculated by HPTLC method. All stability studies, along with the simulation method, represented the stability of simvastatin in nanoformulation.  Establishment of adequate shelf life also was achieved. This work evidenced the extensive stability offered by chitosan polymers to the prodrug simvastatin. Also, give insight when the problem of poor stability of drug molecules limits its practical applicability.