Bromhexine is capable of reducing the thickness of thick gel-like slippery substance (mucus) from the respiratory tract (mucolytic agent). It facilitates easy removal (by coughing out) of mucus from the respiratory tract by making it thin and less sticky
Menthol primarily activates the cold-sensitive TRPM8 receptors in the skin. Menthol, after topical application, causes a feeling of coolness due to stimulation of 'cold' receptors by inhibiting Ca++ currents of neuronal membranes. It may also yield analgesic properties via kappa-opioid receptor agonism
Terbutaline belongs to a class of medications called beta agonists. It works by relaxing and opening the airways, making it easier to breathe