Centrifugation: When plasma is required, or when not using a serum gel separator tube, follow these instructions: 1  Draw 12 mL of whole blood for each 5 mL of serum or plasma needed. 2  Centrifuge for at least 15 minutes at 2200-2500 RPM. 3  Pipette the serum or plasma into a clean plastic screw-cap vial and attach the label.
Buccal administration; Naloxone; Naltrexone; opioid antagonist; Pharmacokinetics; First-pass metabolism Summary The opioid antagonists naloxone and naltrexone are both known to undergo extensive first-pass metabolism after oral dosing. The buccal route was investigated as a potential alternative to oral administration. Oral and buccal bioavailabilities of naloxone and naltrexone were determined in rats. Less than 1 % of oral naloxone or naltrexone was bioavailable, but buccal administration resulted in approximately 70% bioavailability for each drug.
Naltrexone blocks the effects of opioid medication, including pain relief or feelings of well-being that can lead to opioid abuse. An opioid is sometimes called a narcotic. Naltrexone is used as part of a treatment program for drug or alcohol dependence. Naltrexone is used to prevent relapse in people who became dependent on opioid medicine and then stopped using it. Naltrexone can help keep you from feeling a need to use the opioid. Naltrexone is also used to treat alcoholism by reducing your urge to drink alcohol. This may help you drink less or stop drinking completely. Naltrexone will not cause you to sober up and will not decrease the effects of alcohol you recently consumed. Naltrexone is not a cure for drug addiction or alcoholism.