Integrated precipitation and solidification strategies for fast-dissolving amorphous valsartan nanocomposites

Poor aqueous solubility and nanoparticle instability remain key challenges in the development of solid oral formulations for BCS class II drugs. In this study, valsartan nanoparticles were prepared by reverse liquid antisolvent precipitation and stabilized using drying- and carrier-mediated strategies. Crystalline valsartan Form E was first prepared and characterized, and solvent screening was performed to select an appropriate precipitation medium. In the presence of Pluronic F-127, stable nanosuspensions with an average particle size of approximately 30 nm and a narrow size distribution (PDI ≈ 0.196) were obtained. Spray drying and freeze drying with AEROSIL^® 200 produced solid amorphous formulations, as confirmed by PXRD and DSC. Both dried nanosystems released more than 80% of valsartan within 10 min, whereas spray-dried micronized valsartan required approximately 60 min to reach a comparable dissolution level. Montmorillonite K10 functionalized with protamine sulfate was further used for nanoparticle recovery and stabilization. The optimized VMP nanocomposite containing 40% valsartan and 3 mg protamine sulfate per gram of carrier showed enhanced initial dissolution. Overall, controlled antisolvent precipitation combined with carrier surface engineering provides an effective strategy for improving the dissolution performance of poorly water-soluble drug nanoparticles.