Current opinion of muco-active drug research: strategies and problems

In general, mucoactive drugs are classified into several groups. However, since many drugs have overlapping effects, it is difficult to classify the drugs into groups based on their major actions. It has been reported that many mucoactive drugs have antioxidant effects. It is reasonable to suggest that an anti-inflammatory property is crucial to demonstrate effectiveness in a clinical context. From this point of view, we have evaluated several mucoactive drugs over two decades. Of these, we will consider the following drugs with anti-inflammatory properties: sodium aceneuramate; glucocorticoids; traditional Chinese medicines; and new cysteine derivatives. On the basis of these findings, we believe that the efforts to seek for compatible actions between glucocorticoids and oriental medicines may provide new opportunities for development of ideal mucoactive drugs with specified actions, i.e. suppression of gene expression.