Transdermal therapeutic system

Abstract

A therapeutic system for supplying active substances to the skin consists of a backing layer remote from the skin, with at least one active substance depot. The depot may consist of a fluid active substance or a fluid composition comprising an active substance delivery control matrix. There is also included an adhesive fixing device for fixing the therapeutic system on the skin. The therapeutic system is characterized in that the active substance depots (14) consist of at least one adjuvant having a supporting and distributing function by being provided with a planar textile material completely surrounded by matrix (12).

Description

FIELD OF THE INVENTIONThe invention relates to a therapeutic system for applying active substances to the skin, with a backing layer remote from the skin, at least one active substance depot, an active substance distribution device which is linked with the active substance depot, an active substance delivery control device controlling the delivery of the active substance through the system and a pressure sensitive adhesive fixing device for the therapeutic system on the skin, its use and process for the production thereof.BACKGROUND OF THE INVENTIONTherapeutic systems for the transdermal administration of medicaments supply one or more active substances at a predetermined rate and in continuous manner over a fixed period to a given application point on the skin.These systems are therapeutic precision instruments ensuring a continuous active substance release.Such therapeutic systems can have both a topical and a systemic action and the large number of active substances which can be ...

AI Technical Summary

Benefits of technology

tion of the system. Thus, it is an advantage of the invention that now active substances, which are thermally unstable and / or volatile can be introduced during manufacture into transdermal systems in the form of a depot and without any thermal stressing. There is no need for stages, such as the mixing of the reservoir matrix material with the active substance, and instead said material becomes saturated with the active substance at room temperature during the storage of the therapeutic system. Production is simplified due to the omission of the production stages for the active substance-saturated matrix.

Due to the fact that here a reservoir matrix with its own control function is used, which is inter alia determined by the migration speed of the active substance through the matrix, there is no need to provide a control membrane, which requires additional process stages and membrane material during production. The depot can consist of pure active substance, which can be solid or fluid, but may contain also inert adjuvants. The term "inert" is here understood to mean that active substance and adjuvant do not react with one another. An "inert" adjuvant can also be a substance having physiological effects, such as e.g. dimethylsulfoxide (DMSO) or the like, which e.g. increases the permeability of the skin. Suitable adjuvants are also support materials which make the active substance depot insensitive with respect to pressure and tension application, as well as carriers. Thus, the support material may be an inert adjuvant of planar fabric material for providing and supporting a distributing function. For example, a non-woven fabric may serve as an inert adjuvant and as the supporting fabric and assist the uniform distribution of nicotine or any other active substance referred to hereafter. In other words, such fabric material will facilitate the processing of the active substance.

It is possible to use active substances which can be applied in transdermal manner and typical examples of these are given below.

Corticosteroids: hydrocortisone, prednisolone, beclomethasone-propionate, flumethasone, triamcinolone, triamcinolone-acetonide, fluocinolon, fluocinolinacetonide, fluocinolon-acetonide acetate, clobetasolpropionate, etc.

Analgesics, anti-inflammatory agents: acetaminophen, mefenamic acid, flufenamic acid, diclofenac, diclofenac-sodium-alclofenac, oxyphenbutazone, phenylbutazone, ibuprofen, flurbiprofen, salicylic acid, 1-menthol, camphor, sulindac-tolmetin-sodium, naproxen, fenbufen, etc.

Hypnotically active sedatives: Phenobarbital, amobarbital, cyclobarbital, triazolam, nitrazepam, lorazepam, haloperidol, etc.

Problems solved by technology

The known systems are difficult to manufacture and have a complicated structure.

One problem of conventional systems is that of being able to process readily volatile active substances, because the evaporation of the active substance is difficult to control during production.

Thermally sensitive active substances can only be used to a limited extent in the system in the case of matrices or therapeutic systems which have to be thermally treated and which are produced with heat treatment stages.

This process is not suitable for volatile and thermally sensitive active substances, because it includes thermal treatment stages.

The production of such control membrane-surrounded microcapsules is extremely complicated and expensive and cannot be performed for many active substances.

The mixing of the active substance-containing microcapsules under a reservoir material constitutes a further difficult process stage, during which the microcapsules can easily be damaged or destroyed, which can lead to an unsatisfactory constancy of the active substance content in the finished therapeutic system.

The process of U.S. Pat. No. 3,598,123 is difficult to perform for liquid active substances, particularly if the liquid substance is present in readily volatile form.

However, the known depot plaster is disadvantageous in that the liquid therein flows freely and can easily run out if the adhesive or welded edges are damaged and also requires an expensive control membrane, which must be provided in addition to the active substance distribution device in order to kinetically control the delivery of the active substance.

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