Enhancement of Valsartan Solubility by Amorphous solid Dispersion Ternary System: An Optimization and Characterization

Valsartan has poor water solubility, particularly at a pH below 5 due to its pH-dependent solubility. This limits its bioavailability. To enhance the solubility and dissolution rate of valsartan solid dispersion, we prepared it using the spray drying technique in a ternary system. Kollidon VA64 and Kolliphor P407 were utilized in various ratios for its preparation. Drug solubility, crystallography, and dissolution of Val-ASD were evaluated to examine the effect of formulation on its physicochemical characteristics. The molecular interactions between the drug, polymer, and surfactant, as well as amorphization, were analysed using FTIR, DSC, and XRD. Optimisation was conducted utilising the full factorial design approach with a confidence level of 95%. Valsartan was prepared as a solid dispersion that showed a 39-fold increase in solubility compared to its pure form. Furthermore, the formulation was found to accelerate the rate of dissolution. The X-ray diffraction (XRD) and differential scanning calorimetry (DSC) profiles indicated complete amorphization, while the Fourier transform infrared (FTIR) profile displayed hydrogen bonding and hydrophobic interactions between the drug and matrix, which collectively contribute to its enhanced characteristics. Solubility and dissolution were improved in a dependent manner with respect to Kollidon VA64 and Kolliphor P407.