By Venkat Yadav, Adhikrao Yadav
In the present investigation, the enhancement of solubility, dissolution rate and other physicochemical properties of roxithromycin (RTM) were carried out by preparing the recrystallized agglomerates using solvent change technique with three solvents system. Based on the solubility of RTM in different organic solvents the best solvent (ethanol), non-solvent (distilled water) and bridging liquid (chloroform) were selected. The effect of different hydrophilic polymers like hydroxyl propyl methyl cellulose (HPMC), Polyethylene glycol (PEG) and polyvinyl pyrrolidone (PVP) were studied on the solubility, dissolution rate and other physicochemical properties. The optimized recrystallized agglomerates were evaluated for flowability, packability, wettability and compared to raw crystals of RTM. The agglomerates were also characterized by differential scanning calorimetry (DSC), powder X-ray diffraction (XRPD), Fourier transforms infrared spectroscopy (FTIR) and scanning electron microscopy (SEM).The recrystallized agglomerates showed improvement in solubility, dissolution rate and other physicochemical as compared to RTM crystals. The optimized recrystallized agglomerates with HPMC showed good sphericity as well as improvement in in vitro drug release comparative to agglomerates with other hydrophilic polymers. The improved compaction properties of the agglomerated crystals were due to their fragmentation during compression. The DSC showed a decrease in the melting enthalpy indicating disorder in the crystalline content. The XRD also revealed a characteristic decrease in crystallinity.FTIR study revealed that no chemical changes in prepared recrystallized agglomerates. It was concluded that the used hydrophilic polymers can be employed to prepare recrystallized agglomerates for enhancing the solubility and dissolution rate of RTM.
Key Words : Roxithromycin, solvent change technique, physicochemical properties, recrystallized agglomerates, packability, wettability.
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