A new mucotropic agent--in vitro and in vivo evaluation of 2-alpha-thenoylthiopropionylglycine (bronchoplus).

A new mucotropic agent, 2-alpha-thenoylthiopropionylglycine (TTPG) has been evaluated using two in vitro mucus models (pig gastric mucin and human bronchial mucus) and an in vivo model, the oral administration for a period of 7 days to a mini-pig fitted with a tracheal-pouch. TTPG at 2% concentration caused a 40% reduction in the viscosity of mucus gels in vitro, as compared to a control with water. Tracheal mucus samples collected from the pouch were examined rheologically and biochemically. The amount of glycoprotein secreted increased after administration of TTPG (440 to 616 micrograms/mg dry weight). The glycoproteins also appeared to be more acidic after TTPG. An increase in the sulphydryl concentration of the mucus was observed, suggesting that a hydrolysis product of TTPG had crossed the blood-mucus barrier. An increase in the viscosity and elasticity of the mucus gel occurred during the treatment period.