Adhesive matrix with hydrophilic and hydrophobic domains and a therapeutic agent
An adhesive matrix and adhesive formulation are described. The adhesive matrix is comprised of a hydrophilic domain and a hydrophobic domain, and a therapeutically active agent contained in the matrix in a supersaturated, stable, condition. The hydrophilic domain and the hydrophobic domain are co-soluble in a solvent system, to provide a homogeneous blend in which the active agent is solubilized. The proportion of the hydrophilic domain and hydrophobic domain is selected to optimize, or maximize, solubility of active agent in the matrix.
1. An adhesive matrix, comprising:
a hydrophilic domain consisting of a polyvinylpyrrolidone-vinyl acetate copolymer;
a hydrophobic domain consisting of a polyisobutylene and polybutene mixture and an acrylic acid/vinyl acetate copolymer, wherein the polyisobutylene and polybutene mixture is present in an amount of about 7 -15 wt % based on the total weight of the adhesive matrix, and the acrylic acid/vinyl acetate copolymer is present in an amount of about 50-60 wt %, based on the total weight of the adhesive matrix; and
an active agent selected from the group consisting of donepezil, ropinrole, lidocaine, and oxybutynin;
wherein the active agent is present in an amount of about 15-25 wt % based on the total weight of the adhesive matrix, and wherein the active agent is present at a concentration above its saturation concentration in the hydrophobic domain;
wherein the hydrophilic domain and the hydrophobic domain are co-soluble in a solvent system and present in the adhesive matrix in a proportion to one another to solubilize an amount of the active agent greater than the amount of the active agent soluble in either domain alone, and
wherein the adhesive matrix does not contain any component acting as a cross-linking agent for the acrylic polymer.
2. The adhesive matrix of claim 1 , wherein the polyisobutylene and polybutene mixture comprises a high molecular weight polyisobutylene having an average molecular weight ranging from about 500,000 to about 1,500.000 Daltons and a medium molecular weight polyisobutylene having an average molecular weight ranging from about 25,000 to about 100,000 Daltons.
3. The adhesive matrix of claim 1 , comprising between 10-25 wt % hydrophilic domain.
4. The adhesive matrix of claim 1 , comprising between about 35-80 wt % hydrophobic domain.
5. The adhesive matrix of claim 1 , wherein the polyvinylpyrrolidone-vinyl acetate copolymer is about 10-20 wt %.
6. A device for transdermal administration of an active agent, the device comprising an adhesive matrix layer according to claim 1 .
7. The adhesive matrix of claim 1 , wherein the acrylic acid/vinyl acetate copolymer is not a methacrylate copolymer.