Progesterone PLGA/mPEG-PLGA Hybrid Nanoparticle Sustained-Release System by Intramuscular Injection

Purpose To prepare sustained-release PLGA/mPEG-PLGA hybrid nanoparticles of progesterone (PRG), and evaluate the descending required administration dosage in vivo. Methods PRG hybrid nanoparticles (PRG H-NPs) based on PLGA/mPEG-PLGA were compared with PRG nanoparticles (PRG-NPs) of pure PLGA as the matrix and PRG-oil solutions. Nanoparticles (NPs) were formed by the method of nanoemulsion, and the pharmacokinetics of the sustained-release PRG H-NPs in male Sprague dawley (SD) rats were investigated. The rats were randomly divided into four groups, each group received: single dose of PRG H-NPs (14.58 mg/kg, i.m.) and PRG-NPs (14.58 mg/kg, i.m.), repeated dosing for 7 days of PRG-oil (2.08 mg/kg, i.m.) solution (Oil-L) and a higher dosage of PRG-oil (6.24 mg/kg, i.m.) solution (Oil-H), respectively. Results In the pharmacokinetic test, the PRG H-NPs exhibited a comparatively good sustained-release effect against the PRG-NPs without mPEG-PLGA and PRG-oil solution. The pharmacokinetic parameters of the PRG H-NPs, PRG-NPs, Oil-L and Oil-H were AUC(0-t)(ng.h.mL(-1)) 8762.1, 1546.1, 1914.5, and 12,138.9, t(1/2) (h) 52.7, 44.1, 8.4 and 44.6 respectively. Conclusions Owing to the modification of PEG, PRGH-NPs can act as safe delivery platforms for sustained-release of drugs with a lower dosage required.