Pharmacokinetics of 14C-isosorbide dinitrate after administration in various sustained-release formulations
Chasseaud, L.F.; Taylor, T.; Major, R.M.; Taylor, I.W.; Luckow, V.; Darragh, A.; Lambe, R.F.
Arzneimittel-Forschung 33(9): 1298-1301
1983
ISSN/ISBN: 0004-4172 PMID: 6685511 Document Number: 204561
To study the influence of various in vitro release rates and of coadministration with food on bioavailability of isosorbide dinitrate (ISDN; isoket retard 40) and its mononitrate metabolites from sustained-release formulations the pharmacokinetics of two experimental batches of tablets with different release rates containing 40 mg 14C-ISDN each were studied in six human volunteers. One of the formulations was not only administered after fasting but aslo with a standard meal. In all cases approx. 80% of the administered radioactivity were recovered in the urine and 5% in the faeces during 3 days demonstrating extensive absorption. Any influence of release rates or food on absorption rates could not be detected. When administered after fasting either formulation was bioequivalent. Coadministration of a meal enhanced ISDN plasma levels in some subjects although no statistically significant difference in extent of bioavailability was observed. Availability of the mononitrates was unaffected by food.