Plasma levels of nitroglycerin generated by three nitroglycerin patch preparations, Nitradisc, Transiderm-Nitro and Nitro-Dur and one ointment formulation, Nitrobid.

Twenty-four healthy male subjects participated in a study comparing plasma concentrations of nitroglycerin generated by single applications of Nitradisc 32 mg, Transiderm-Nitro 50 mg and Nitro-Dur 104 mg patches and from one inch of Nitrobid 2% ointment. The three patch preparations are designed to release 10 mg nitroglycerin systemically over a 24 h period. Nitrobid ointment is intended to deliver 15 mg nitroglycerin per inch of ointment, and to be reapplied at least every 8 h. Blood was taken for nitroglycerin assay up to and including 24 h after each application. Assay for nitroglycerin was performed using a gas chromatography-mass spectrometry technique. Plasma concentrations of nitroglycerin were sustained up to the 24 h mark with all three patch preparations, but not with application of Nitrobid ointment. Nitrobid was associated with a rapid rise in nitroglycerin plasma concentrations maximal 1 h after application. Plasma concentrations of nitroglycerin absorbed from Nitrobid ointment fell below those absorbed from all three patch preparations after 8 h. Clinically, all four formulations were similar with respect to side effects, with headache and dizziness being the most common.