The potentiality of interaction of folic acid with Beta-cyclo-dextrin [Beta-Cy D] and hydroxypropyl Beta-cyclodextrin [HP-Beta-Cy D] was investigated by spectmphotometric and solubility methods.
Both methods revealed the formation of 1: 1 inclusion complexes between folic acid and the investigated cyclodextrins. The effect of temperature on the stability of folic acid-Cy D complexes was investigated. The complexes were found to undergo partial dissociation with increasing temperature above 25 degree, however, they were still present at body temperature. Calculating the amount of drug solubilized in free as well as complexed form at different temperatures, revealed that solubilization of the drug by Cy Ds is entirely due to complex fonnation. The enthalpy and entropy of interaction were also computed from the values of the stability constant at different temperatures. The negative enthalpy and entropy values indicate that complexation of folic acid with Cy Ds is an exothermic reaction, increasing the orderliness of the system. The inclusion complexation of folic acid with Cy BS in the solid phase was also confirmed by I. R. The dissolution rate was determined according to the USP method, apparatus 1, at pH 1.2, 4.6 and 6.8. In all cases, the dissoiution profiles of the complexes reveal enhanced dissolution properties compared to the drug
R. M. Khalil ,R. M. Khalil ,D. M. Mostafa ,M. A. Kassem ,
Inclusion complexes of folic acid with beta-cyclo-dextrin and hydroxypropyl beta-cyclodextrin,
Egypt. J. Pharm. Sci. 2004;
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