Pharmaceutical aspects of transdermal nitroglycerin

Transdermal delivery has become an important method for the delivery of nitroglycerin in the treatment of angina. Developments have been made over the decade and the purpose of this mini-review is to highlight some of the more important developments in a critical manner. Many of the concepts are of general relevance to the transdermal field and it is instructive that many of the system designs for other drugs that are delivered transdermally have been based on the information gained from GTN delivery. Safety is of paramount importance but for a product to be successful it must also have good patient compliance. The future of transdermal delivery must consider these two aspects and the role that basic physical chemistry has to play in this cannot be underestimated. From first principles it is possible to predict that GTN is a good transdermal candidate, from an in vitro assessment it is possible to predict the expected plasma levels. The more difficult aspect to predict is the potential side effects from the drug itself and problems such as tolerance.