Study on the Preparation of Nifedipine-Loaded Oral Copolymer Micelles and its Pharmacokinetics in Rats

The objective of this paper was to prepare nifedipine-loaded oral copolymer micelles and to improve bioavailability of hydrophobic drugs. The methoxy poly(ethylene glycol)-b-polycaprolactone diblock copolymer (mPEG-b-PCL) we developed was the research object; solvent evaporation method was utilized to prepare nifedipine-loaded copolymer micelles, and the drug concentration, drug-loaded amount, and entrapment efficiency were also determined. Transmission electron microscopy and dynamic light scattering were used to characterize the morphology and size distributions of micelles, and the in vivo pharmacokinetics were studied in rats with the research objects of nifedipine-loaded oral copolymer micelles. The drug concentration, drug-loaded amount, and entrapment efficiency of mPEG-b-PCL-nifedipine micelles were (69.39 ± 4.33) μg mL−1, (3.35 ± 0.21) %, and (8.67 ± 0.54) %, respectively. The micelles were globular shaped with a narrow size distribution and a mean diameter of (34.8 ± 3.2) nm, and the relative bioavailability of the micelles we developed was 246.20 % when compared with the tablets available in the market. The mPEG-b-PCL-nifedipine oral copolymer micelles can improve the bioavailability of hydrophobic drugs. Oral polymer micelles drug delivery system has a good prospect.