Al Dalaty Adnan, Gualeni Benedetta, Coulman Sion A, Birchall James C
School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, CF10 3NB, UK.
Drug Deliv Transl Res. 2022 Feb;12(2):335-349. doi: 10.1007/s13346-021-01091-5. Epub 2021 Dec 3.
Microneedle (MN)-based technologies have been proposed as a means to facilitate minimally invasive sustained delivery of long-acting hormonal contraceptives into the skin. Intradermal administration is a new route of delivery for these contraceptives and therefore no established laboratory methods or experimental models are available to predict dermal drug release and pharmacokinetics from candidate MN formulations. This study evaluates an in vitro release (IVR) medium and a medium supplemented with ex vivo human skin homogenate (SH) as potential laboratory models to investigate the dermal release characteristics of one such hormonal contraceptive that is being tested for MN delivery, levonorgestrel (LNG), and provides details of an accompanying novel two-step liquid-liquid drug extraction procedure and sensitive reversed-phase HPLC-UV assay. The extraction efficiency of LNG was 91.7 ± 3.06% from IVR medium and 84.6 ± 1.6% from the medium supplemented with SH. The HPLC-UV methodology had a limit of quantification of 0.005 µg/mL and linearity between 0.005 and 25 µg/mL. Extraction and detection methods for LNG were exemplified in both models using the well-characterised, commercially available sustained-release implant (Jadelle®). Sustained LNG release from the implant was detected in both media over 28 days. This study reports for the first time the use of biologically relevant release models and a rapid, reliable and sensitive methodology to determine release characteristics of LNG from intradermally administered long-acting drug delivery systems.
基于微针(MN)的技术已被提议作为一种手段,以促进长效激素避孕药以微创方式持续递送至皮肤。皮内给药是这些避孕药的一种新的给药途径,因此没有既定的实验室方法或实验模型可用于预测候选微针制剂的皮肤药物释放和药代动力学。本研究评估了一种体外释放(IVR)介质和一种补充了离体人皮肤匀浆(SH)的介质,作为潜在的实验室模型,以研究一种正在测试用于微针递送的激素避孕药左炔诺孕酮(LNG)的皮肤释放特性,并提供了一种配套的新型两步液 - 液药物萃取程序和灵敏的反相高效液相色谱 - 紫外检测方法的详细信息。从IVR介质中萃取LNG的效率为91.7±3.06%,从补充了SH的介质中萃取效率为84.6±1.6%。高效液相色谱 - 紫外方法的定量限为0.005μg/mL,线性范围在0.005至25μg/mL之间。使用特征明确的市售缓释植入剂(Jadelle®)在两种模型中举例说明了LNG的萃取和检测方法。在两种介质中均检测到植入剂在28天内持续释放LNG。本研究首次报道了使用具有生物学相关性的释放模型以及一种快速、可靠且灵敏的方法来确定皮内给药长效药物递送系统中LNG的释放特性。