Strepronin is a mucolytic drug. A mucolytic agent is any agent which dissolves thick mucus usually used to help relieve respiratory difficulties. The viscosity of mucous secretions in the lungs is dependent upon the concentrations of mucoprotein as well as the presence of disulfide bonds between these macromolecules and DNA. (en)
An expectorant increases bronchial secretions and mucolytics help loosen thick bronchial secretions. Expectorants reduce the thickness or viscosity of bronchial secretions thus increasing mucus flow that can be removed more easily through coughing, Mucolytics break down the chemical structure of mucus molecules. The mucus becomes thinner and can be removed more easily through coughing. (en)