Effect of macromolecules on aqueous solubility of cholesterol and hormone drugs.

The solubility of cholesterol and some hormone drugs in aqueous macromolecule solutions was investigated. Polyvinylpyrrolidone, dextrans, and heparin increased the solubilities of progesterone, testosterone, and diethylstilbestrol, while acacia, pectin, and carrageenans decreased their solubilities. Dextrans increased the solubilities of cholesterol and the three hormone drugs. Acacia and pectin greatly increased cholesterol solubility; however, these macromolecules significantly decreased progesterone and diethylstilbestrol solubilities and slightly decreased progesterone solubility. Heparin decreased cholesterol solubility and increased progesterone, testosterone, and diethylstilbestrol solubilities. Carrageenans significantly decreased cholesterol, progesterone, and testosterones solubilities and had little effect on diethylstilbestrol solubility. A strong bathochromic shift in the absorption spectra of progesterone and testosterone in polyvinylpyrrolidone solutions indicated an attachment between the polymer and the C=O group of the steroids.