Distribution of [3H] Prednisolone in Rat Plasma and Tissues after Intramuscular Administration in Liposome-Entrapped Form

Open Access
Publisher Website
Google Scholar
Abstract
Positively charged, sonicated liposomes with [3H]prednisolone entrapped in them were administered to the rat hip muscle to examine its distribution in comparison with that after administration of free [3H]prednisolone. Plasma concentration of [3H]prednisolone in liposome-entrapped form was high for a long period of time, the values being 8 times after 30 min and 24 times after 24 h compared to that in free form. The concentration of [3H]prednisolone in liposome-entrapped form in the liver, kidneys and spleen was 4-10 times and, in the lung and pancreas, 8-10 times higher than that in free form after 30 min and 24 h. In the adrenal, the concentration of liposome-entrapped prednisolone was lower than that in free form after 30 min and 1 h, the former remained in the tissue, and the concentration was maintained at a high level after 24 h, being about 28 times higher than that in free form. Even in the duodenum and large intestine, the liposome-entrapped form remained in the tissue for a long period of time. A small dose administered i.m. may be useful, since it allows the steroid to remain in the plasma and tissues for a long period of time.