RESULTS OF ANIMAL STUDIES WITH CIPROFIBRATE, A NEW ORALLY EFFECTIVE HYPOLIPIDEMIC DRUG

Ciprofibrate, a new orally active phenoxyisobutyrate, is significantly more hypolipidemic than is the reference clofibrate. In hyperlipidemic rats ciprofibrate suppresses the increase in blood lipids 33% at a daily dosage of 0.6-3 mg/kg. The corresponding dosage for clofibrate is 125-460 mg/kg. Based on studies with cholesterol pools pre-labeled with [14C]mevalonate or with cholesterol-labeled pools in ciprofibrate-treated normolipidemic rats, ciprofibrate inhibited cholesterol biosynthesis. No evidence of the presence of 7- or 24-dehydrocholesterol was obtained in the sera of ciprofibrate-treated rats as shown by gas chromatography examination. The order of hypolipidemic effectiveness of ciprofibrate in hyperlipidemic rats provides a basis for anticipating that ciprofibrate will be hypolipidemic in hyperlipoproteinemic humans considered at high risk of acquiring coronary artery disease.