title: Implant pellets I: effects of compression pressure on in vivo dissolution of delmadinone acetate pellets.
abstract: A formulation containing 95% delmadinone acetate was compressed at three different pressures. These pressures resulted in a pellet density difference of 19%. In vivo dissolution profiles were determined for five lots of pellets. The pellets were implanted subcutaneously in rats, removed periodically, and assayed chemically for remaining steroid. The resulting data were fit, using the computer program NONLIN, to a dissolution model. The dissolution rate for the lot with the lowest density made at the lowest compression was statistically (p less than 0.05) different from the four other lots. A possible explanation for this increased dissolution rate could be that channeling occurs within the pellet, thereby increasing the effective dissolving surface. The results also indicate that equivalent dissolution rates between lots are reached at a certain compression and density.
mesh_terms: D000818:Animals; D002715:Chlormadinone Acetate / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000378:metabolism; D004339:Drug Compounding; D004343:Drug Implants; D011312:Pressure; D011372:Progestins / Q000008:administration & dosage / Q000378:metabolism*; D051381:Rats; D012995:Solubility; D013499:Surface Properties; D013997:Time Factors
chemical_list: D004343:Drug Implants; D011372:Progestins; D002715:Chlormadinone Acetate