This application discloses a method of inhibiting degradation of the antidepressant bupropion hydrochloride in a solid pharmaceutical formulation, so that the pharmaceutical formulation will maintain at least 80% of its initial bupropion potency after one year.
This is a continuation of Ser. No. 08/296,252 filed on Aug. 25, 1994, now U.S. Pat. No. 5,541,231, which is a continuation of Ser. No. 105,437, filed Aug. 12, 1993, now U.S. Pat. No. 5,358,970.
Stabilized bupropion hydrochloride pharmaceutical compositions are disclosed that are free of acid additives and provide for a sustained release of the bupropion hydrochloride. The particulate bupropion hydrochloride may be coated with a membrane coating and large-size particles may also be used. Methods for treating individuals using the stabilized bupropion hydrochloride pharmaceutical compositions are also provided.
The present invention pertains to a stabilized pharmaceutical composition which comprises a mixture of (a) a pharmaceutical agent unstable at a pH above about 3.5; and (b) a stabilizing amount of an acidic pharmaceutically acceptable carrier to stabilize the pharmaceutical agent. The acidic pharmaceutically acceptable carrier is a dried premixture of a pharmaceutically acceptable carrier and an aqueous solution of an acid. The stabilized pharmaceutical composition has a pH value of less than about 3.5, and when stored at a temperature of about 50.degree. C. for about 4 weeks at about 27% relative humidity, retains at least about 80% of the pharmaceutical agent. This invention also pertains to sustained-release forms of the stabilized pharmaceutical compositions as well as to novel methods for preparing and using the stabilized pharmaceutical compositions and to stabilized pharmaceutical compositions made by the novel method.
The invention includes an apparatus and method for transdermal delivery of bupropion base. In the method of this invention, patient is administered parenterally a bupropion base in an amount effective to alleviate withdrawal symptoms and to prevent or reduce craving of nicotine in said patient. Alternatively, an effective amount of bupropion base is delivered to alleviate depression in a patient. A transdermal delivery system includes a bupropion base. The bupropion base can be mixed with an acceptable pharmaceutical carrier.
Methods and formulations for making extended release bupropion hydrochloride tablets using direct compression, and tablets formed thereby, are provided which combine bupropion hydrochloride, binders such as polyethylene oxide or hydroxypropyl cellulose, a filler such as lactose, glidants and lubricants under low shear conditions to form hard, chip-resistant tablets which exhibit improved cohesiveness and are easily and reproducibly formed without adhering to the compression punches and dies.
