This study developed a sustained-release lipid liquid crystalline (LLC) system for leuprolide acetate (LA) and investigated the feasibility of using the lipase inhibitor orlistat (Orl) to modulate the matrix degradation and prolong the drug release period. The LA-LLC formulation was characterized by using polarized light microscopy (PLM), rheological analysis, and in vitro release studies to guide optimization. The impact of Orl on the sustained-release performance of LA-LLC was evaluated through in vitro degradation, in vitro release, and pharmacokinetic studies in rats. All animal protocols were approved by the Laboratory Animals Care and Use Committee of Yantai University (registration number is YTU20210319) (Yantai, China). Results showed that the LLC system utilizing glycerol dioleate (GDO) as the oil phase exhibited optimal sustained-release characteristics. The optimized LA-LLC formulation comprised soybean phosphatidylcholine, GDO, ethanol, and LA at a mass ratio of 44.5∶44.5∶10∶1. This gel exhibited a hexagonal phase structure by PLM. It demonstrated shear-thinning capacity characteristic of a pseudoplastic fluid. In vitro degradation and release results indicated that Orl significantly inhibited lipid degradation and prolonged drug release. Pharmacokinetic results in rats indicated that the addition of inhibitor Orl prolonged the release period from 42 days to 56 days compared to the LA-LLC group. This study demonstrates that the LA-LLC system, with its structural stability and controllable release, can effectively prolong drug release by employing a lipase inhibitor to regulate matrix degradation. The results of the study provide a novel strategy for the sustained delivery of peptide drugs.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |