SUSTAINED RELEASE HORMONAL PREPARATIONS

Abstract

ABSTRACT Determination of radioactivity in urine, faeces and various organs in rats was used to monitor the absorption of labelled 6-methyl-17α-acetoxy-4,6-pregnadiene-3,20-dione from polydimethylsiloxane implants or after oral administration. Given orally, peak plasma levels were obtained 4 h after administration. It took about 4 days to reach steady plasma levels when PDS implants were used. For a hypothetical biologically effective dose, megestrol acetate plasma levels were about 15 times higher than when an implant was used. Increased plasma levels seen after oral administration were reflected in increased uptake by various tissues. Compared to levels seen in animals having a PDS implant the increase was 40 times higher in liver, 60 times in kidneys, 8 times in adrenals, 6 times in testes and 12 times higher in the brain.