This occurs when a substance passes from the fluid in the tubular lumen through the apical membrane, across the cytosol , and then into the interstitial fluid.
Yes, it's potent stuff. Cat receive it either as an injection or orally. It takes effect in roughly half an hour, lasting about 8 hours before another administration is necessary. Cats usually react negatively to opiates, but buprenorphine is an exception. That's one reason vets use it if they can receive the necessary special certification.
Based on the buprenorphine content, this medicine has a half-life of 24 to 42 hours. This means that it takes 24 to 42 hours for the level of buprenorphine to drop by 50 percent in your blood. Therefore, it may take several days, or even a week or longer, for this drug to be mostly out of your system.