Solid Dispersion Preparation of a Macrolide Drug Using Natural and Synthetic Polymers to Enhance its Solubility and Bioavailability: A Pharmacokinetics Application

Abstract

. To enhance the solubility of azithromycin, natural and synthetic hydrophilic polymers were
used through mini spray drying technique. Solid dispersions were characterized by various techniques like
UV/Visible spectroscopy, FTIR, thermal analysis, SEM analysis and powder XRD. In vitro and in vivo analysis were carried out at pH 6.0 and in animal models, respectively. Solid dispersions show enhanced aqueous
solubility as compared to standard drug. FTIR, Thermal studies, SEM analysis and powder XRD analysis
reveals about the enhanced solubility and stability of solid dispersions. The pharmacokinetics parameters
were calculated from the plasma concentration vs time curve, by using a validated HPLC method. The value
of all pharmacokinetics parameters of solid dispersions were 1.2-1.7 times greater than the commercially
available azithromycin tablets with enhanced value of tmax. This clearly indicates the enhancement in the
solubility of azithromycin after solid dispersion preparation using mini spray drying technique.