The Biopharmaceutics Classification System (BCS), developed in the 1990s for oral immediate release drugs, is utilized by R&D scientists and regulators to streamline product development and regulatory approval timelines. This elegant, science-based approach is based on three in vitro parameters representing a combination of drug substance physicochemical and physiological properties with respect to oral administration; specifically a dose number, dissolution number, and absorption number. Interest in applying similar principles to pulmonary drug products is increasing. To date the focus has been on dissolution of drugs in the lung. A workshop co-sponsored by the AAPS, FDA, and USP was held in March 2015 in Baltimore to evaluate if a systematic framework to classify pulmonary drugs could be established, and the scope and relevance of such a classification scheme. The focus of the workshop was to address factors influencing drug delivery and action in the lungs rather than the development of a specific model or system. Presentations included: the history and evolution of the oral BCS (described as the “giBCS” by Gordon Amidon), lung physiology and the fate of inhaled drugs, regional aerosol deposition and dose, macroscopic clearance mechanisms, particle dissolution, drug permeability, absorption and their interplay with pharmacokinetics and pharmacodynamics. Background discussions were followed by three separate breakout sessions each focused on the BCS concepts of dose, dissolution, and absorption numbers as they would apply to pulmonary drug delivery. The workshop concluded that a classification system, if fully developed, would be a useful tool for formulators and discovery chemists. The scope of such a system, at this point in time, would not include aspects relevant to regulatory relief. The goals of the workshop were met by identifying an opportunity to develop a model to classify pulmonary drugs based on physicochemical attributes specific to lung physiology and drug delivery.

中文翻译：

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肺生物药物分类系统AAPS / FDA / USP研讨会的范围和相关性，2015年3月16日至17日，马里兰州巴尔的摩

1990年代开发的用于口服速释药物的生物制药分类系统（BCS）被研发科学家和监管机构用来简化产品开发和监管批准时间表。这种优雅的，基于科学的方法基于三个体外参数，这些参数代表了与口服给药有关的药物物理化学和生理特性的组合。特别是剂量数，溶出数和吸收数。将相似原理应用于肺部药物产品的兴趣正在增加。迄今为止，重点一直放在药物在肺中的溶解上。由AAPS，FDA和USP共同赞助的研讨会于2015年3月在巴尔的摩举行，以评估是否可以建立用于分类肺部药物的系统框架，以及这种分类方案的范围和相关性。研讨会的重点是解决影响药物在肺中的传递和作用的因素，而不是开发特定的模型或系统。演讲内容包括：口服BCS（由Gordon Amidon称为“ giBCS”）的历史和演变，肺部生理学和吸入药物的命运，局部气溶胶沉积和剂量，宏观清除机制，颗粒溶解，药物渗透性，吸收和吸收。它们与药代动力学和药效学的相互作用。在背景讨论之后，进行了三个单独的分组会议，每个分组会议都集中讨论了BCS剂量，溶出度和吸收数的概念，因为它们适用于肺部药物的输送。研讨会得出的结论是，分类系统如果得到充分开发，对于配方设计师和发现化学家而言将是一个有用的工具。目前，这种系统的范围将不包括与监管救济有关的方面。通过确定一个机会开发模型来对肺部药物进行分类，该模型基于特定于肺部生理学和药物输送的理化属性来实现，从而实现了研讨会的目标。