Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
School of Future Technology, University of Chinese Academy of Sciences, Beijing, 101408, China.
Drug Deliv Transl Res. 2022 Apr;12(4):944-956. doi: 10.1007/s13346-021-01057-7. Epub 2021 Sep 13.
To facilitate the storage and use of poly (lactic-co-glycolic acid) (PLGA)-based microneedles (MNs) in hot seasons and regions, thermally stable MNs loaded with levonorgestrel (LNG) were developed. Due to its good biocompatibility and high glass transition temperature (T), Hydroxypropyl methylcellulose (HPMC) was added to the PLGA-based MNs to increase thermal stability. MNs with HPMC exhibited excellent thermal stability at high temperatures. After the MNs has been applied to the skin for 10 min, the backing layer of the MNs was dissolved by contact with the interstitial fluid of skin, which resulted in the separation of the MN tips from the backing layer. The MN tips were implanted intradermally and sustained-release LNG. Biodegradable polymers were used to encapsulate the LNG, providing long-acting contraception. The in vitro release rate of LNG from the MNs reached 72.78%-83.76% within 21 days. In rats, the MNs maintained plasma concentrations of LNG above the human contraceptive level for 8-12 days. In mice, the time required for complete degradation of the MN tips was 12-16 days. MNs have excellent medication adherence due to the advantages of painlessness, minimally invasive, and self-administered. MNs can make long-acting contraceptives more readily available to humans.
为了便于在炎热季节和地区储存和使用聚（丙交酯-乙交酯）（PLGA）基微针（MN），开发了负载左炔诺孕酮（LNG）的热稳定 MN。由于其良好的生物相容性和较高的玻璃化转变温度（T），将羟丙基甲基纤维素（HPMC）添加到基于 PLGA 的 MN 中以提高热稳定性。HPMC 基 MN 在高温下表现出优异的热稳定性。MN 应用于皮肤 10 分钟后，MN 的背衬层与皮肤间质液接触而溶解，导致 MN 尖端与背衬层分离。MN 尖端被植入真皮内并持续释放 LNG。可生物降解聚合物被用于封装 LNG，提供长效避孕。在 21 天内，LNG 从 MN 中的体外释放率达到 72.78%-83.76%。在大鼠中，MN 使 LNG 的血浆浓度在 8-12 天内保持在人类避孕水平之上。在小鼠中，MN 尖端完全降解所需的时间为 12-16 天。MN 具有无痛、微创和自我给药的优势，因此具有良好的用药依从性。MN 可以使长效避孕药更易于人类获得。
