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.
Descriptions. Naltrexone is used to help narcotic dependents who have stopped taking narcotics to stay drug-free. It is also used to help alcoholics stay alcohol-free. The medicine is not a cure for addiction.altrexone will cause withdrawal symptoms in people who are physically dependent on narcotics. Naltrexone treatment is started after you are no longer dependent on narcotics. The length of time this takes may depend on which narcotic you took, the amount you took, and how long you took it.