ABSTRACT
The effect of varying the concentration of polycarbophil and particle size on its physical characteristics viz swelling, flowability and compressibility was investigated. The effect of using polycarbophil, in different concentrations of varying particle sizes, on the characteristics of indomethacin tablets prepared by direct compression was also studied. The swelling of polycarbophil increased as its particle size increased from <0.063 to 1 mm. The particles having particle size range 0.5-0.8, 0.8-1.0 and >1 mm showed excellent flowability. The amount of indomethacin released was found to decrease as the polycarbophil concentration and the particle size increase. The effect of polycarbophil particle size on the dissolution of indomethacin was more pronounced at 5% concentration. 20% polycarbophil, of particle size 0.18-0.8 mm, could be a useful additive in tablet formulation as disintegrant to its bioadhesive character
Subject(s)
Pharmacokinetics , TabletsABSTRACT
Inclusion complexation of khellin and beta cyclodextrin [beta CD], gamma cyclodextrin [gamma CD] and hydroxypropyl beta cyclodextrin [HP beta CD] in water and in solid state were studied by the solubility method, UV spectrophotometry, differential scanning calorimetry [DSC], X-ray diffractometry, IR-spectroscopy and dissolution study. Solubility of khellin in water increased with the addition of cyclodextrins. The complex system formed had 1: 1 stoichiometric ratio with beta, gamma and HP beta CD. The apparent 1: 1 stability constant of khellin complexes with beta, gamma and HPBCD were 27.71 M-1, 66.67 M-1, 32.46 M-1 respectively. Phase solubility studies revealed 14, 24 and 35 fold increase in the solubility of khellin in the presence of cyclodextrins. More evidence of complex formation was obtained from the analysis of UV, IR, DSC and X-ray diffraction studies. The dissolution rate of khellin was significantly enhanced by complexation with cyclodextrins