Solubility parameter based drug delivery system and method for altering drug saturation concentration

A pressure sensitive adhesive transdermal drug delivery system comprising:

• (a) a blend consisting essentially of about 2% to about 96% by weight of a polyacrylate and about 98% to about 4% by weight of a polysiloxane, said blend being in an amount of about 99% to about 50% by weight of said system and wherein said ratio of polyacrylate to polysiloxane is from about 2:98 to about 86:14 by weight of said blend and wherein the permeation rate is controlled by varying the relative proportions of the polymers;
• (b) a drug in the amount of about 0.3% to about 50% by weight of said system and wherein the drug is selected from the group consisting of nitroglycerin, isosorbide dinitrate, isosorbide mononitrates, quinidine sulfate, procainamide, bendroflumethiazide, chlorothiazide, nifedipine, nicardipine, timolol, propranolol, verapamil, diltiazem, captopril, clonidine, prazosin, testosterone, estropipate, 17.beta.-estradiol, 17.beta.-estradiol valerate, equilin, mestranol, estrone, estriol, 17.beta.-ethinyl estradiol, diethylstilbestrol, progesterone, 19-norprogesterone, norethindrone, norethindrone acetate, melengestrol, chloramdinone, ethisterone, medroxyprogesterone acetate, hydroxyprogesterone caproate, ethynodiol diacetate, norethynodrel, 17-alpha-hydroxyprogesterone, dydrogesterone, dimethisterone, ethinylestrenol, norgestrel, demegestone, promegestone, megestrol acetate, buprenorphine, naloxone, haloperidol, codeine, lidocaine, tetracaine, dyclonine, dibucaine, cocaine, procaine, mepivacaine, bupivacaine, etidocaine, prilocaine, benzocaine, fentanyl, hydrocortisone, cortisone, prednisolone, prednisone, halcinonide, betamethasone, ibuprophen, naproxen, fenoprofen, fenbufen, indoprofen, ketoprofen, suprofen, indomethacin, piroxicam, aspirin, salicylic acid, chlorpheniramine, theophilline, albuterol, terbutaline, metaproterenol, carbuterol, fenoterol, quinterenol, rimiterol, solmefamol, soterenol, tretoquinol, dopamine, phenylpropanolamine, epinephrine, pilocarpine, choline, acetylcholine, methacholine, carbachol, bethanechol, muscarine, arecoline, scopolamine, eucatropine, atropine, penicillin, tetracycline, papaverine, tamoxifen, dextroamphetamine, mazindol, alprazolam, chlordiazepoxide, clorazeptate, halazepam, oxazepam, prazepam, chlonazepam, flurazepam, triazolam, lorazepam, diazepam, thiopropazate, chlorpromazine, triflupromazine, mesoridazine, piperacetazine, thioridazine, acetophenazine, fluphenazine, perphenazine, trifluoperazine, chlorprothixene, thiothixene, bromperidol, loxapine, molindone, pyrimethamine, misoprostol, enprostil, levodopa, selegiline, baclofene, and mixtures thereof;
• (c) optionally, an effective amount of a co-solvent for the drug, said amount being up to about 30% by weight of said system;
• and
• (d) optionally, an effective amount of an enhancer, said amount being up to about 20% by weight of said system.