| Summary: | 碩士 === 國立東華大學 === 生物技術研究所 === 95 === Oral dosage is the most popular way of administration of drugs. When taking medicine, the solubility of a drug plays an important role in the absorption in the digestive tract. Hydrophobic drugs are insoluable in water, but they can easily diffuse to the wall of small intestines. Therefore it is important to increase the solubility and monomer concentration of hydrophobic drugs. Sulfobutyl ether beta cyclodextrin (SBE-CD) can combine with molecules of hydrophobic drugs to form a complex; therefore, increase the solubility of hydrophobic drugs. However investigation of, the monomer concentration and it’s relation with the
SBE-CD are limited.
In this study, we used a diffusion cell to analyse the monomer concentration of hydrocortisone, tolbutamide and estradiol in SBE-CD solution. The monomers of hydrocortisone, tolbutamide and estradiol, due to small particles, can pass dialysis membrane, but the combined complex and the uncombined SBE-CD, due to large particles, can not. Then the Fick’s first law was used to estimate different permeability coefficients and monomer concentrations in donor side solution. According to mass balance and mass action laws, we estimated the ratios of the combined complex to the total SBE-CD and the equilibrium
constants.
Hydrocortisone exhibits the highest ratio among the three hydrophobic drugs. In contrast, the ratio for tolbutamide is nearly zero. The difference may attribute to different structure and different position
of fountional groups for these drug molecules.
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