Effect of polymer excipient on crystallization and film formulation in vitro release and in vivo evaluation

Abstract

xvi newlineABSTRACT newlineCrystallization is a process of organizing atoms and molecules into a particular newlinestructure called a crystal. There are certain methods like cooling crystallization and newlineevaporative crystallization. The nature of the resulting crystal depends largely on factors newlinelike air pressure, temperature, and time of fluid evaporation. Co-processing of ibuprofen newlinewith SMCC was carried out by solid-state ball milling, and aqueous state equilibration newlinefollowed by freeze-drying to investigate the effect of silicified-microcrystalline cellulose newlineon the ligand. The binding energy between MCC and SiO2, and ibuprofen and SMCC newlinewere found as 1.11 and 1.73 kcal/mol respectively. The hydrogen bond lengths were newlinevarying from 2.028 to 2.056 and#506;. Interaction of Si atom of SMCC molecule with Pi- newlineOrbital of ibuprofen has shown the bond length of 4.263 and#506;. Significant improvement in newlinethe dissolution of ibuprofen has been observed as a result of the interaction. newlineCrystalline product of lamotrigine-salicylic acid was prepared at 1:1, 2:1, 3:1 newlinemolar ratios by the solvent evaporation method. The in-vitro drug release of the newlinecrystalline products was carried out in 0.1 M HCl (pH 1.2). The presence of newlinecharacteristic peaks for peptides in the experimental crystalline products in Fourier newlinetransform infrared spectroscopy (FTIR) spectra indicated the formation of a strong newlinecovalent bond between LG and SA. In the DSC thermograms, the melting endotherm of newlinethe formulations showed different melting points than pure LG. X-ray diffraction (XRD) newlinedata depicted sharp peaks for the formulations, which further justified the successful newlineformation of a new crystalline phase. The crystal product, L1S1 (at 1:1 molar ratio) newlineexhibited higher strain and dislocation value compared to other formulations. The newlinedissolution profile of L1S1 in the simulated gastric fluid was also higher rather than that newlineof the pure drug and other formulations. newlineIBU crystal products were produced in presence of the selected polymers. Results newlineshowed that in presence of polymers; the crystallization yield of IBU was higher th newline