Development and evaluation of an inhalation chamber for in vivo tests

ABSTRACT The bioavailability, toxicity, and therapeutic efficacy of a drug is directly related to its administration route. The pulmonary route can be accessed by inhalation after fumigation, vaporization or nebulization. Thus, pharmacological and toxicological evaluation accessed by an apparatus specifically designed and validated for this type of administration is extremely important. Based on pre-existing models, an inhalation chamber was developed. This presents a central structure with five animal holders. The nebulized air passes directly and continuously through these holders and subsequently to an outlet. Evaluation of its operation was performed using clove essential oil, a nebulizer, and a flow meter. The air within the chamber was collected by static headspace and analyzed by gas chromatography with a flame ionization detector. For this purpose, a 2.5 minutes chromatographic method was developed. The air flow in each of the five outputs was 0.92 liters per minute. During the first minute, the chamber became saturated with the nebulized material. Homogeneous and continuous operation of the chamber was observed without accumulation of volatile material inside it for 25 minutes. The inhalation chamber works satisfactorily for in vivo tests with medicines designed to be administrated by inhalation.

摘要：药物的生物利用度、毒性与治疗效果与其给药途径直接相关。经熏蒸、汽化或雾化方式实施吸入后，可实现经肺给药途径。因此，采用专门针对该给药方式设计并验证的装置开展药理学与毒理学评价具有极为重要的意义。本研究基于现有模型开发了一款吸入染毒舱（Inhalation Chamber），其主体结构包含五个动物固定架，雾化气流可直接且持续地流经各固定架后从排气口排出。本研究采用丁香精油、雾化器与流量计对该装置的运行性能进行了评价：通过静态顶空法（Static Headspace）采集舱内空气，并采用气相色谱法（Gas Chromatography, GC）结合火焰离子化检测器（Flame Ionization Detector, FID）进行分析，为此开发了时长2.5分钟的色谱分析方法。测试结果显示，五个固定架对应的气流流速均为0.92升/分钟；运行首分钟内舱内即达到雾化物质饱和状态；连续运行25分钟期间，舱内始终保持均匀稳定的运行状态，未出现挥发性物质累积。综上，该吸入染毒舱可满足经吸入给药的药物体内实验需求，运行效果良好。