Applicants claim priority under 35 U.S.C. §119 of German Application No. 100 13 504.8 filed Mar. 20, 2000. Applicants also claim priority under 35 U.S.C. §365 of PCT/DE01/00687 filed Feb. 23, 2001. The international application under PCT article 21(2) was not published in English.
The invention relates to a plaster containing an active agent comprising at least
Such a plaster containing an active agent is described in, for example East German Patent 278494 A1. The active membrane therein is formed, in particular, from a skin-compatible, pressure-sensitive adhesive, in which the molecular sieve/active agent adduct is incorporated. From this complex, the active agent is released by desorption, caused by diffusion of transpired water of the skin into the pressure-sensitive adhesive. Thereafter the active agent is dissolved and diffuses to the surface of the skin as a function of the composition of the pressure-sensitive adhesive.
The following advantages are associated with the use of plasters containing an active agent in connection with medical treatment:
In connection with a further development, the object of the invention is to provide a plaster containing an active agent that satisfies the following criteria:
For the purpose of achieving this object, the inventive plaster containing an active agent is now characterized according to the body of claim 1 in that
Practical alternative embodiments of the plaster containing an active agent are specified in claims 2 through 19.
Another object of the invention is to provide a method for production of the inventive plaster containing an active agent.
According to the characteristics of claim 20, the method for production of the new plaster containing an active agent is now characterized by the following steps:
The foregoing dehydration and/or loading step(s) are/is performed, in particular, in the presence of an inert gas, such as nitrogen. The dehydration and/or loading step(s) are/is preferably performed under normal pressure. The loading step itself can be accomplished by means of a ball mill, for example.
Advantageously, the assembly step is followed by a drying process, which is carried out at 30 to 100° C., preferably 50 to 70° C., for 2 to 6 hours, preferably 3 to 4 hours. In this way, a self-adhesive matrix is formed.
Alternatively, the molecular sieve/active agent adduct can be prepared in such a way that, in combination with a non-adhesive matrix, it triggers the self-adhesive capability of the active membrane.
The invention will now be explained on the basis of exemplary embodiments with reference to schematic drawings, wherein:
According to
Active membrane 3 in turn comprises matrix 4, in which molecular sieve/active agent adduct 5 is incorporated. In particular, a sodium aluminosilicate of the formula
Na86[(AlO2)86·(SiO2)106]·m(m′)H2O
which contains a basic molar quantity (m=276) of water of crystallization in the not yet dehydrated state is used as the molecular sieve. During the partial dehydration step, at least 20%, preferably 40 to 70% of the moles of water are removed. The partially dehydrated molecular sieve with the reduced molar quantity (m′; for example, m′=200) is now loaded with an active agent Z.
During skin contact 6 of active membrane 3, water is now drawn from the skin or from the wound region and taken up (adsorption) by molecular sieve/active agent adduct 5, whereupon desorption of active agent Z takes place. At the same time, the content of water of crystallization in the molecular sieve increases. Thus the molecular sieve regains the water of crystallization that had been removed from it by partial dehydration.
The fact that molecular sieve/active agent adduct 5 basically contains water of crystallization ensures an appropriate moist environment. In this way, desorption of active agent Z by means of water acting as a solvent or dispersant agent is facilitated. In addition, the moist environment creates ideal conditions for cell growth factors and also serves for immune defense.
Examples of plasters containing an active agent are:
A further exemplary embodiment is illustrated in the scope of the same figure. In this case the molecular sieve having a uniform degree of dehydration is loaded with a first active agent Z1, and a second active agent Z2, which are present in different degrees of loading, so that molecular sieve/active agent adduct 5 releases active agents Z1, and Z2 sequentially upon skin contact 6 of active membrane 3, as illustrated by the different arrow thicknesses. The two active agents have approximately the same molecular weight. The following numerical example will illustrate this. The molecular sieve has a degree of dehydration of 70%. At a total degree of loading with active agents Z1, and Z2 equal to 60%, Z1, accounts for 40% and Z2 for 20%. By virtue of the greater loading concentration, active agent Z1, is released more rapidly than active agent Z2, and therefore the therapeutic effects are staggered in time.
An example of a medical use of this type would be the combination of an antithrombotic (Z1) with an antibiotic (Z2), which can also be cited for the exemplary embodiment according to
A first and second molecular sieve 11 and 12 of the same type but different degrees of dehydration are incorporated in matrix 10, as in the following example:
For approximately equal molecular weights of active agents Z3 and Z4, the degree of loading is about the same for each.
Upon skin contact 13 of active membrane 9, active agents Z3 and Z4 are released sequentially, once again as symbolized by the arrows of different thickness. In other words, adduct 11 with the greater degree of dehydration will take up water more readily than adduct 12. As a result, active agent Z3 will be released more rapidly than active agent Z4, and once again the therapeutic effects will be staggered in time.
Independent of the exemplary embodiments, it is practical if the following parameters apply for plasters 1 and 7 containing an active agent:
The plaster containing an active agent is usually enclosed in a sterile package. Alternatively, active membrane 3 and 9 can be covered with a removable protective film.
The values of degree of dehydration and degree of loading cited in the specification and in the claims are relative to the condition after completion of partial dehydration or loading, i.e. before metabolic exchange of water and active agent.
Number | Date | Country | Kind |
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100 13 504 | Mar 2000 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/DE01/00687 | 2/23/2001 | WO | 00 | 9/18/2002 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO01/70202 | 9/27/2001 | WO | A |
Number | Date | Country |
---|---|---|
278 494 | May 1990 | DD |
278 492 | May 1990 | DE |
278 494 | May 1990 | DE |
Number | Date | Country | |
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20030032909 A1 | Feb 2003 | US |