چكيده لاتين :
Purpose of this study was to investigate the effect of the presence of the water
soluble polymers viz HPMC, PVP and PEG 6000 on aqueous solubility and
complexation abilities of felodipine with or without presence of ~-cyclodextrin (~CD)
and HP~CD by phase solubility studies . The data revealed the initial increase in drug
solubility followed by plateau in the presence of relatively low polymer concentration
i.e. 0.25-0.5 %w/v. Phase solubility diagrams of felodipine in ternary system
showed similar behaviour to binary system without ~CD. Addition of water soluble
polymer to ~CD solution improved ~CD solubilizing efficiency due to increase in
~CD complexing power toward felodipine. In binary system solubility was found
2.5 to about 10 time s higher than in water which was further improved in the
presence of 0.25% w/v water soluble polymer. Ternary systems with ~CD showed
highest increments in solubility towards felodipine, with 78.8 %, 81.8% and 74%
improvement after the addition of 0.25% w/v HPMC, PVP and PEG6000,
respectively. Our study confirmed that addition of small amounts of hydrophilic
polymer is useful strategy for improving the solublization and complexing abilit ies
of cyclodextrins thus allowing less cyclodextrin to be needed to solubilize given
amount of drug . This offers economic advantage. All the polymers under study
showed synergistic effect on felodipine cyclodextrin solublization by increasing
complexation efficiency.The highest solubility improvement up to 81.8% was
obtained for ~CD ternary system when 0.25% w/v of PVP was used.
