In vitro evaluation and in vivo pharmacodynamic studies of spironolactone suppositories administered to rats

In vitro release of spironolactone from different suppository bases and in vivo pharmacodynamic effect in rats were studied. Suppositories containing 10 mg of spironolactone were prepared using polyethylene glycol [PEG], Witepsol E75, theobroma oil and Suppocire A. The hardness test of the suppositories revealed that the theobroma oil base produced relatively brittle suppositories, whereas polyethylene glycol base, in particular mixture of 1000: 4000 produced hard and stable suppositories. The release of spironolactone was fast from polyethylene glycol bases. Incorporation of Tween 80 in lipophilic bases remarkably enhanced the release of spironolactone from these bases. Using the dialyzing technique to study release characteristics of the drug from the suppositories, the maximum release of the drug was obtained from Witepsol E75 suppositories containing 5%Tween 80 followed by release from PEGs. The suppository formulations were evaluated for their pharma effect in rats. The in vivo data showed that the different suppository formulations had a significant influence on the extent of spironolactone dynamic effect. Among these suppository bases, the hydrophilic polyethylene glycol 1500, Witepsol E75+5% Tween 80 and theobroma oil were found to be the best

Bioequivalence of commercial ranitidine tablets

Bioequivalence of two different marketed ranitidine tablets, Tanidina [150 mg, Ferrer, Spain] and Antagonin [150 mg, Arab Pharmaceuticals, Jordan] was compared to the innovate product, Zantac [150 mg, Glaxo, UK]. In vitro results were similar for the three br and s as specified in USP XXII monograph for ranitidine tablets. A three-way r and omized crossover study was conducted on 18 healthy male volunteers. The three products were administered, each as a single oral dose of 150 mg, separated by a one week washout period. After dosing, serial blood samples were collected up to 9 hours. Plasma was analyzed for ranitidine by a sensitive and accurate high performance liquid chromatographic [HPLC] method. Plasma concentration data were subjected to statistical pharmacokinetic analysis for subjects, periods and formulation using analysis of variance. Paired t-test and least significant difference [LSD] were also performed on the derived pharmacokinetic parameters and on plasma concentrations at each sampling time. In vitro studies showed that all three products, Tanidina, Antagonin and Zantac, were pharmaceutically equivalent. In vivo investigations indicated no statistically significant differences between the three products in any of the pharmacokinetic characteristics used to asses bioequivalency. It was concluded that the three br and s of ranitidine tablets [Tanidina, Antagonin, and Zantac] are bioequivalent