Intramuscular Rate Of Disappearance Of Oily Vehicles In Rabbits Investigated By Gamma-Scintigraphy

The fate of oily vehicles administered intramuscularly was followed with whole body gamma-scintigraphy. Groups of six rabbits received injections administered into the upper hind leg. No differences were observed in disappearance rates of various volumes (50-400 mu l) of either fractionated coconut oil or sesame oil. Addition of two different concentrations of a drug substance, zuclopenthixol decanoate, to fractionated coconut oil did not influence the disappearance rate of the vehicle. Half-lives of the two oils at the injection site were in the order of 1 week for fractionated coconut oil and 1 month for sesame oil. Both oils spread approximately 25% along the muscle fibres during the first 24 h after administration. Radioactivity was mainly excreted with the urine. Insignificant amounts of radioactivity were found in blood, liver and carcass after 10 days. (C) 1998 Elsevier Science B.V. All rights reserved.