[Pharmacological studies on expectorants (author's transl)]

Area of Science:

• Pharmacology
• Respiratory Physiology

Background:

• Evaluating expectorant efficacy is crucial for respiratory drug development.
• The Perry and Boyd method (1941) is a foundational technique for assessing expectorants.
• Improvements are needed to optimize experimental conditions and drug evaluation.

Purpose of the Study:

• To refine the Perry and Boyd method for evaluating expectorant efficacy in rabbits.
• To establish optimal experimental conditions for quantitative collection of respiratory tract fluid (RTF).
• To assess the effects of various drugs on RTF volume (VRTF).

Main Methods:

• Redesigned air conditioning apparatus and tracheal cannula for rabbits.
• Quantitative collection of RTF via postural drainage under controlled temperature and humidity.
• Determination of drug effects on VRTF.

Main Results:

• Bromhexine and emetine significantly increased VRTF, with bromhexine showing superior efficacy.
• Antitussives (codeine, dextromethorphan) and bronchodilators (isoproterenol, clorprenaline, C-78) decreased VRTF.
• Other antitussives (fominoben, eprazinone) increased VRTF.

Conclusions:

• The refined method provides a reliable platform for evaluating expectorants that increase VRTF.
• The method is also applicable for assessing drugs that decrease VRTF, such as antitussives and bronchodilators.
• This optimized approach enhances the assessment of diverse respiratory drug efficacies.