School of Pharmacy, University of Otago, Dunedin, New Zealand.
Woolcock Institute of Medical Research and Discipline of Pharmacology, Sydney Medical School, Glebe, Australia.
Expert Opin Drug Deliv. 2021 Aug;18(8):1091-1100. doi: 10.1080/17425247.2021.1882991. Epub 2021 Feb 5.
: Drug particles inhaled via the respiratory system must first dissolve in the respiratory tract lining fluid (RTLF) that lies on the surfaces of airways and alveoli, so that they are absorbed and have therapeutic action. Artificial simulated RTLFs are often used for dissolution studies to determine the solubility and dissolution of inhaled drug particles. Such studies can be used to predict bioavailability minimizing the requirement for studies. Numerous studies have been conducted to develop bio-relevant simulated RTLFs; however, to date, there is no singular simulated RTLF that closely resembles human RTLF.: This review focuses on the composition of natural and simulated RTLFs and their use in dissolution studies.: There is variation in the composition and thickness of RTLF along the respiratory tract. Identification of the actual concentration of components of endogenous RTLF present in different areas of the respiratory tract helps in the development of region-specific simulated RTLFs. It is recommended that region-specific simulated RTLFs can be prepared by varying concentration of major RTLF components like mucus/gel simulants, lipids/surfactants, peptides/proteins, and inorganic/organic salts.
: 通过呼吸系统吸入的药物颗粒必须首先溶解在位于气道和肺泡表面的呼吸道衬里液（RTLF）中，以便被吸收并发挥治疗作用。人工模拟的 RTLF 常用于溶解研究，以确定吸入药物颗粒的溶解度和溶解。这些研究可用于预测生物利用度，从而减少研究需求。已经进行了许多研究来开发与生物相关的模拟 RTLF；然而，迄今为止，还没有一种单一的模拟 RTLF 非常接近人体 RTLF。: 本文综述了天然和模拟 RTLF 的组成及其在溶解研究中的应用。: RTLF 沿呼吸道的组成和厚度存在差异。确定呼吸道不同区域存在的内源性 RTLF 成分的实际浓度有助于开发特定区域的模拟 RTLF。建议通过改变主要 RTLF 成分（如粘液/凝胶模拟物、脂质/表面活性剂、肽/蛋白质和无机/有机盐）的浓度来制备特定区域的模拟 RTLF。
