Scopolamine transdermal therapeutic system

The transdermal scopolamine system is a circular flat patch designed for continuous release of scopolamine following application to an area of intact skin on the head, behind the ear. Each system contains 1.5 mg of scopolamine base. Scopolamine is (alpha)-(hydroxymethyl)ben-zeneacetic acid 9-methyl-3-oxa-9-azatricyclo [3.3.1.0 2,4] non-7-yl ester. Scopolamine is a viscous liquid that has a molecular weight of 303.35 and a pKa of 7.55-7.81. The transdermal system is a film 0.2 mm thick and 2.5 cm2, with four layers. Proceeding from the visible surface toward the surface attached to the skin, these layers are a 

Handbook of Pharmaceutical Manufacturing Formulations Semisolid Products 

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Furthermore, central-acting antimuscarinic drug are effective in the treatment of motion sickness. In this indication the alkaloid scopolamine has been shown to be effective. It can be applied orally, intra venously or via a transdermal therapeutic system. 

Transdermal therapeutic systems (TTS) of nitroglycerin (1), isosorbide dinitrate (2), scopolamine (3) or clonidine (4) have been throughly investigated in vitro and in vivo. However, there have been few studies of skin permeation of ionizable water soluble drugs. 

Transdermal administration can avoid first-pass metabolism as well as provide a large surface area for continuous-controlled administration of drugs with short biological half-lives and narrow therapeutical indices. The route has been used for nitroglycerin ointments, and transdermal therapeutical systems (patches) have been developed for scopolamine, nitroglycerin, clonidine, estradiol, and nicotine. 

The Transdermal Therapeutic System-scopolamine, shown schematically in Figure 3, is a multilayer laminate. It is comprised of a steady-state drug reservoir containing scopolamine in a polymeric gel, sandwiched between an impermeable backing membrane and a rate-controlling, microporous membrane. On the dermal side of the rate-controlling mem-... 

A. Characteristics of Vitro Delivery of Scopolamine from the Transdermal Therapeutic System-scopolamine into an Infinite Sink... 

The present Transdermal Therapeutic System-scopolamine is 2.5 cm in area, and its strength is specified by its temporal pattern of drug release 200 yg priming dose, 10 Vig/hr for 72 hours. Results of large scale clinical studies have indicated that the system is a safe and effec-... 

Applied to the skin in a transdermal patch (transdermal therapeutic delivery system), this drug is used to prevent or reduce the occurrence of nausea and vomiting that are associated "with motion sickness. Diphenhydramine Chlorpromazine Ondansetron Dimenhydrinate Scopolamine... 

Scopolamine was the first drug to be marketed as a transdermal delivery system (Transderm-Scop) to alleviate the discomfort of motion sickness. After oral administration, scopolamine has a short duration of action because of a high first-pass effect. In addition, several side-effects are associated with the peak plasma levels obtained. Transderm-Scop is a reservoir system that incorporates two types of release mechanims a rapid, short-term release of drag from the adhesive layer, superimposed on an essentially zero-order input profile metered by the microporous membrane separating the reservoir from the skin surface. The scopolamine patch is able to maintain plasma levels in the therapeutic window for extended periods of time, delivering 0.5 mg over 3 days with few of the side-effects associated with (for example) oral administration. 

Membrane permeation-controlled transdermal drug delivery (Fig. 5.2) has been successfully applied in therapeutic systems for scopolamine (prevention of motion sickness for a 3-day period), nitroglycerin (prophylaxis against attack of angina pectoris over a 24-h period), clonidine (control of hypertension for a 7-day period), and fentanyl (control of constant pain for 72 h). 

Since the permeability of skin to scopolamine is sufficiently high to permit transdermal administration at therapeutically useful rates, it has been possible to design a membrane modulated delivery system, which delivers scopolamine at a predictable and constant rate. 

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