CIEPQPF, Chemical Engineering Department, University of Coimbra, Pólo II - Pinhal de Marrocos, Rua Sílvio Lima, 3030-790 Coimbra, Portugal.
Int J Pharm. 2011 Nov 28;420(2):231-43. doi: 10.1016/j.ijpharm.2011.08.040. Epub 2011 Aug 31.
In this work we employed a supercritical solvent impregnation (SSI) process using a scCO(2)+EtOH (5% molar) solvent mixture to impregnate acetazolamide (ACZ) into commercially available silicone-based soft contact lenses (Balafilcon A, Pure Vision, Bausch & Lomb). Contact lenses (SCLs) drug-loading was studied at 40°C and 50°C, and from 15 MPa up to 20 MPa, and using low depressurization rates in order to avoid any harm to SCLs. The effect of impregnation processing time on the loaded ACZ amounts was also studied (1, 2 and 3h). In vitro drug release kinetics studies were performed and the released ACZ was quantified spectrophotometrically. Several analytical techniques were employed in order to characterize the processed and non-processed SCLs in terms of some of their important functional properties. Obtained results demonstrated that ACZ-loaded therapeutic Balafilcon A SCLs can be successfully prepared using the employed SSI process. Furthermore, it was possible to control ACZ loaded amounts and, consequently, to adjust the final ACZ release levels into the desired therapeutic limits, just by changing the employed operational conditions (P, T, processing time and depressurization rate) and without change some of their most important thermomechanical, surface/wettability and optical properties. Obtained soft contact lenses can be potentially employed as combined biomedical devices for simultaneous therapeutic and correction of refractive deficiencies purposes.
在这项工作中，我们采用超临界溶剂浸渍（SSI）工艺，使用 scCO₂+EtOH（5%摩尔）溶剂混合物将乙酰唑胺（ACZ）浸渍到市售的硅基软隐形眼镜（Balafilcon A、Pure Vision、Bausch & Lomb）中。研究了在 40°C 和 50°C 以及 15 MPa 至 20 MPa 的温度下，使用低压降速率浸渍隐形眼镜（SCL）的情况，以避免对 SCL 造成任何损害。还研究了浸渍处理时间对负载 ACZ 量的影响（1、2 和 3 小时）。进行了体外药物释放动力学研究，并通过分光光度法定量测定释放的 ACZ。采用了几种分析技术来评估处理和未处理的 SCL 在一些重要功能特性方面的特性。研究结果表明，采用所采用的 SSI 工艺可以成功制备负载 ACZ 的治疗性 Balafilcon A SCL。此外，通过改变所采用的操作条件（P、T、处理时间和降压速率），可以控制负载的 ACZ 量，从而调整最终的 ACZ 释放水平达到所需的治疗范围，而不会改变它们一些最重要的热机械、表面/润湿性和光学特性。所获得的软性隐形眼镜可作为用于同时治疗和矫正屈光缺陷目的的组合式生物医学装置。
