Pharmacokinetics and bioavailability of isosorbide-5-mononitrate in humans.

The relative bioavailability of isosorbide-5-mononitrate from two different formulations (MONOCLAIR, ISMO) was investigated in a double-blind randomized cross-over study in 8 healthy human subjects. After single orale doses of 40 mg the plasma concentration and the urinary excretion of isosorbide-5-mononitrate were measured over 24 hours. The comparison of the results obtained over the whole experimental period showed a significantly higher plasma concentration with a higher renal excretion after MONOCLAIR, the latter changes being insignificant as compared with those after ISMO, the reference drug. Thus the two formulations are judged to be at least equivalent with regard to their drug bioavailability.

Plasma concentration of cutaneously applied trinitroglycerin.

The absorption of trinitroglycerin ointment was studied on ten test persons over a 12-h period. The first plasma concentrations above the minimally detectable levels were found from the 10th min on. A first peak of absorption is measureable at 30 min. The inter- and intraindividual variations in the degree of absorption are most probably due to variability of absorption and various bioavailability. The absorption process can be substantiated during the entire time in which the ointment daub is in place. Typical trinitroglycerin effects such as reduction of blood pressure, elevation of heart rate, and increase in headaches were observed in healthy volunteers.

The bioavailability of spironolactone hydrochlorothiazide combination preparation.

In a single-blind, randomized cross-over study the bioavailability of Spironothiazid (50 mg spironolactone, 50 mg hydrochlorothiazide) was investigated in six healthy male volunteers by comparing the same dose of the well-established drugs Aldactone dragees, 50 mg, and Esidrex tablets, 25 mg. After 6 days treatment with 2 X 1 Spironothiazid or 2 X 1 Aldactone dragees, 50 mg, plus Esidrex tablets, 25 mg daly, orally, the serum concentrations and the cumulative renal excretion of the active substances were measured after the morning dose on the 7th day of the study. Canrenone (the main metabolite of spironolactone) was measured fluorimetrically, hydrochlorothiazide was determined by gas chromatography. There was no statistically significant difference between the investigated drugs, neither in the areas under the curves nor in the cumulative renal excretion, thus indicating an identical bioavailability.

[Biological availability of spironolactone in two different galenic forms (author's transl)]. / Biologische Verfügbarkeit von Spironolacton in zwei verschiedenen galenischen Zubereitungen.

The biological availability of spironolactone in two different galenic preparations (Spiro-Tablinen and Aldactone-100 Caps) was investigated in a single-blind, randomised, cross-over study in six healthy probands. The serum concentration of canrenone after oral intake of spironolactone (100 mg) was investigated in the steady state as well as the renal excretion of canrenone. There were no statistically significant differences between the two preparations either in the course of the serum concentration of canrenone or in the cumulative renal excretion.