摘要 |
Buprenorphine is a potent analgesic agent, it has been shown to be as effective as morphine. The main clinical application of buprenorphine is to relief postoperative pains or for patients in the terminal phase of cancer. The chance of becoming addiction and abuse is low, therefore it is pretty safe for clinical use. The half life of buprenorphine is short, since its hepatic extraction (extraction ratio is 0.7 to 0.9) and metabolism are high. For these reasons, oral administration of buprenorphine becomes impractical due to the need of giving drug frequiently. The present invention is related to enhancers used in transdermal preparations of narcotic analgesic agents. This invention employs pure components of Chinese herbs in a fixed ratio as transdermal penetration enhancers. Compositions of these transdermal preparations usually include 0.1 to 50% of narcotic analgesic agent, 0.1 to 70% of pure components from Chinese herb as transdermal penetration enhancers, and other necessary excipients for transdermal delivery. Studies for the present invention in nude mice revealed that a transdermal preparation containing 10% of terpineol can delivery 15 mg of buprenorphine through 10 cm2 skin area in 48 hours, which satisfied the need of practical use.
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