Suprofen sustained release kinetics in healthy male volunteers. 1st communication: a single dose open crossover bioavailability study of suprofen sustained release tablets versus capsules.

An open crossover study was performed in 12 healthy male volunteers to compare the bioavailability of alpha-methyl-4-(2-thienyl-carbonyl)phenylacetic acid (suprofen, Suprol) 600 mg sustained release tablets versus the suprofen capsule (2 X 200 mg). The pharmacokinetic profiles in plasma and urine were determined by a HPLC assay. In the dose range studied, the two suprofen formulations were not associated with any clinically significant effects on the blood pressure, heart rate or ECG. The results of the physical and neurological examinations showed no abnormal results. The results of haematology, clinical chemistry and urinalysis also showed no significant modifications. However, increased serum creatinine values were observed in some volunteers following suprofen administration. A drug relationship to this finding cannot be excluded with certainty. Two volunteers complained of nausea and vomiting following administration of two suprofen capsules. For this reason, volunteer no. 9 was withdrawn by the investigator from the study and replaced by an eligible substitute. In general, single doses of the two suprofen formulations investigated, were subjectively and objectively well tolerated. From the suprofen plasma-concentration time profiles, it was apparent that, whilst the elimination of suprofen was similar for both formulations, there was a marked delay in absorption of the tablet formulation. This formulation resulted in statistically significantly later maximum plasma levels and longer mean residence time (p less than 0.001). In comparison to the reference capsule formulation, the tablet had statistically significantly lower (75%) bioavailability. Measurement of suprofen concentrations in the urine indicated that less than 1% of the administered dose was excreted by this route.