In vitro and in vivo evaluation of clarithromycin solid dispersion prepared by spray-drying

Abstract
The aim of this study was to develop solid dispersions (SDs) of Clarithromycin (CLA) using hydrophilic polymer hydroxypropyl- methylcellulose (HPMC) and Xanthan Gum (XNG) as drug carrier. The in vitro dissolution study was performed in dissolution media of pH 6.8 and compared with that of standard drugs. In vivo pharmacokinetic studies were carried out on animal model (rabbits).The thermal behavior of each SDs formulation was studied by differential scanning calorimetry (DSC) analysis. The results concluded that crystalline nature of CLA has been transformed to amorphous form in SDs. Pharmacokinetic parameters were observed to be improved in HPMC as well as XNG based SDs than that of standard drugs. Additionally, powder X-ray diffraction (PXRD) analysis also confirmed the phase transition (crystalline to amorphous) of drug present in SDs. The higher values of Cmax, were found in case of HPMC based SDs, whereas, tmax values were prolonged in SDs based on XNG. Additionally, enhanced half-life values predicted that SDs would have potential to achieve once daily dose and improved patient compliance of drugs. Hence, the formulated SDs of poorly soluble drug, based on HPMC and XNG as carriers, exhibited more hydrophilic nature with enhanced aqueous solubility and therefore improved bioavailability as compared to that of standard drug.