Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK.
Centre for Continuous Manufacturing and Advanced Crystallisation, University of Strathclyde, Glasgow G1 1RD, UK; Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, UK.
J Control Release. 2024 Sep;373:533-546. doi: 10.1016/j.jconrel.2024.07.037. Epub 2024 Jul 27.
Pharmaceutical tablets are often coated with a layer of polymeric material to protect the drug from environmental degradation, facilitate the packaging process, and enhance patient compliance. However, the detailed effects of such coating layers on drug release are not well understood. To investigate this, flat-faced pure microcrystalline cellulose tablets with a diameter of 13 mm and a thickness between 1.5 mm to 1.6 mm were directly compressed, and a film coating layer with a thickness of 80 μm to 120 μm was applied to one face of these tablets. This tablet geometry and immediate release film coating were chosen as a model system to understand how the film coating interacts with the tablet core. The coating hydration and dissolution process was studied using terahertz pulsed imaging, while optical coherence tomography was used to capture further details on the swelling process of the polymer in the coated tablet. The study investigated the film coating polymer dissolution process and found the gelling of dissolving polymer restricted the capillary liquid transport in the core. These findings can help predict the dissolution of film coating within the typical range of thickness (30 μm to 40 μm) and potentially be extended to understand modified release coating formulations.
药片通常会涂覆一层聚合物材料，以保护药物免受环境降解的影响、便于包装过程，并提高患者的顺应性。然而，这种涂层对药物释放的详细影响还不是很清楚。为了研究这一点，选用直径为 13 毫米、厚度在 1.5 毫米至 1.6 毫米之间的平面纯微晶纤维素片，直接进行压缩，并在其中一面涂覆厚度为 80 微米至 120 微米的薄膜涂层。这种片剂几何形状和即时释放薄膜涂层被选为模型系统，以了解薄膜涂层如何与片剂核心相互作用。使用太赫兹脉冲成像研究了涂层的水合和溶解过程，同时使用光相干断层扫描捕捉涂层片剂中聚合物溶胀过程的进一步细节。该研究调查了薄膜涂层聚合物的溶解过程，发现溶解聚合物的胶凝作用限制了核心中的毛细液体传输。这些发现有助于预测典型厚度范围内（30 微米至 40 微米）的薄膜涂层的溶解情况，并有可能扩展到理解改良释放涂层配方。
