Aim To investigate the combined effect of hydroxypropyl-β-cyclodextrin （HP-β-CD） and media pH on the solubility of prostaglandin E1 （PGE1） and construct a theoretical equation for the drug solubility as a functi...Aim To investigate the combined effect of hydroxypropyl-β-cyclodextrin （HP-β-CD） and media pH on the solubility of prostaglandin E1 （PGE1） and construct a theoretical equation for the drug solubility as a function of HP-β-CD concentration and media pH. Methods The solubility of PGE1 under different pH conditions was determined. Then, the drug solubility in different concentrations of HP-β-CD acidic or pH neutral solutions was measured, respectively. Finally, a theoretical solubility equation for the drug as a function of HP-β-CD concentration and media pH was deduced and confirmed in experiment. Results PGEs was solubilized by HP-β-CD or by increasing media pH. The drug solubility as a function of HP-β-CD concentration was found to follow the AL-type complexation model in acidic or neutral pH media, suggesting that both the ionized and neutral drugs form 1：1 molecular ratio complexes. Conclusions The solubility of PGE1 may be improved by increasing media pH or by using HP-β-CD as a solubilizer. HP-β-CD and media pH can produce combined effect on the solubility of PGE1. The deduced equation for the drug solubility in this study effectively characterizes the roles of HP-β-CD and media pH in determining total solubility of the drug.展开更多
Aim To study the effect of complexation with hydroxylpropyl-β-cyclodextrin(HP-β-CD) on the solubility, dissolution rate and chemical stability of prostaglandin E_1 (PGE_1) ,thereby providing a basis for preparing a ...Aim To study the effect of complexation with hydroxylpropyl-β-cyclodextrin(HP-β-CD) on the solubility, dissolution rate and chemical stability of prostaglandin E_1 (PGE_1) ,thereby providing a basis for preparing a stable solid or aqueous preparation of PGE_1 formulatedwith HP-β-CD. Methods The effect of HP-β-CD on the solubility of PGE_1 was studied by phasesolubility method. The formation of inclusion complexes of PGE_1 with HP-β-CD in the aqueoussolution was confirmed by UV spectra, circular dichroism spectroscopy, and that in the solid stateby IR spectra and X-ray diffractome-try. An solid inclusion complex of PGE_1 with HP-β-CD wasprepared by lyophilization. The dissolution rate and stability of the inclusion complex weredetermined and compared with those of PGE_1 alone. Meanwhile, the stability of PGE_1 aqueoussolutions in the presence of HP-β-CD was studied under different pH conditions. Results Thesolubility of PGE_1 increased linearly with increasing HP-β-CD concentration in various pH bufferedsolutions, showing typical A_L-type phase solubility diagrams. The stability and dissolution rateof the solid inclusion complex of PGE_1 were significantly increased, compared with those of purePGE_1 . The stability of PGE_1 in HP-β-CD solutions was also obviously improved under acidic andbasic conditions, but the stabilizing effect was absent under neutral conditions. Conclusions Thesolubility,dissolution rate and chemical stability of PGE_1 are markedly improved by complexationwith HP-β-CD: It is quite possible to prepare a stable PGE_1 inclusion complex-containing soliddosage forms, but almost impossible to obtain a stable aqueous preparation of PGE_1 formulated withHP-β-CD.展开更多
文摘Aim To investigate the combined effect of hydroxypropyl-β-cyclodextrin （HP-β-CD） and media pH on the solubility of prostaglandin E1 （PGE1） and construct a theoretical equation for the drug solubility as a function of HP-β-CD concentration and media pH. Methods The solubility of PGE1 under different pH conditions was determined. Then, the drug solubility in different concentrations of HP-β-CD acidic or pH neutral solutions was measured, respectively. Finally, a theoretical solubility equation for the drug as a function of HP-β-CD concentration and media pH was deduced and confirmed in experiment. Results PGEs was solubilized by HP-β-CD or by increasing media pH. The drug solubility as a function of HP-β-CD concentration was found to follow the AL-type complexation model in acidic or neutral pH media, suggesting that both the ionized and neutral drugs form 1：1 molecular ratio complexes. Conclusions The solubility of PGE1 may be improved by increasing media pH or by using HP-β-CD as a solubilizer. HP-β-CD and media pH can produce combined effect on the solubility of PGE1. The deduced equation for the drug solubility in this study effectively characterizes the roles of HP-β-CD and media pH in determining total solubility of the drug.
文摘Aim To study the effect of complexation with hydroxylpropyl-β-cyclodextrin(HP-β-CD) on the solubility, dissolution rate and chemical stability of prostaglandin E_1 (PGE_1) ,thereby providing a basis for preparing a stable solid or aqueous preparation of PGE_1 formulatedwith HP-β-CD. Methods The effect of HP-β-CD on the solubility of PGE_1 was studied by phasesolubility method. The formation of inclusion complexes of PGE_1 with HP-β-CD in the aqueoussolution was confirmed by UV spectra, circular dichroism spectroscopy, and that in the solid stateby IR spectra and X-ray diffractome-try. An solid inclusion complex of PGE_1 with HP-β-CD wasprepared by lyophilization. The dissolution rate and stability of the inclusion complex weredetermined and compared with those of PGE_1 alone. Meanwhile, the stability of PGE_1 aqueoussolutions in the presence of HP-β-CD was studied under different pH conditions. Results Thesolubility of PGE_1 increased linearly with increasing HP-β-CD concentration in various pH bufferedsolutions, showing typical A_L-type phase solubility diagrams. The stability and dissolution rateof the solid inclusion complex of PGE_1 were significantly increased, compared with those of purePGE_1 . The stability of PGE_1 in HP-β-CD solutions was also obviously improved under acidic andbasic conditions, but the stabilizing effect was absent under neutral conditions. Conclusions Thesolubility,dissolution rate and chemical stability of PGE_1 are markedly improved by complexationwith HP-β-CD: It is quite possible to prepare a stable PGE_1 inclusion complex-containing soliddosage forms, but almost impossible to obtain a stable aqueous preparation of PGE_1 formulated withHP-β-CD.
