Abstract
Objective: This study aimed to formulate and evaluate solid dispersions of acyclovir using Polyethylene Glycol (PEG) polymers (PEG 3350, PEG 4000, and PEG 6000) in varying ratios to improve their oral bioavailability.
Methods: Solid dispersions of acyclovir with PEG 3350, PEG 4000, and PEG 6000 were prepared at different weight ratios (1:5, 1:20, and 5:1) using the solvent evaporation method. Physical mixtures were also prepared for comparison purposes. Characterization involved Differential Scanning Calorimetry (DSC) to study thermal behavior, X-ray powder Diffraction (XRPD) to assess the crystalline state, Fourier Transform Infrared Spectroscopy (FTIR) for molecular interactions, and dissolution studies using USP apparatus type 2 to evaluate drug release profiles.
Results: Among the tested formulations, the solid dispersion of acyclovir with PEG 4000 at a 20:1 ratio demonstrated the most favourable dissolution profile, with over 50% drug release within the first 10 min. DSC analysis indicated a significant reduction in the crystallinity of acyclovir within the solid dispersions, particularly with PEG 4000. XRPD confirmed the transformation of acyclovir to an amorphous state, while FTIR spectroscopy revealed molecular interactions between acyclovir and PEG, indicative of enhanced solubility. Dissolution studies further corroborated the superior performance of the 20:1 PEG 4000 formulation, which showed a remarkable increase in solubility compared to other ratios and physical mixtures. Mathematical modeling using the Weibull and Logistic models suggested controlled and predictable release kinetics for the optimized formulation.
Conclusion: Overall, this study underscores the potential of solid dispersion formulations, particularly the 20:1 ratio of PEG 4000 to acyclovir, in enhancing the oral bioavailability of poorly water-soluble drugs, such as acyclovir, offering valuable insights for pharmaceutical formulations and drug delivery systems.
Publisher
Innovare Academic Sciences Pvt Ltd