tissue the present invention also provides a mucin secretion enhancer comprising compound 1 as an active ingredient administering the mucin secretion enhancer comprising compound 1 as an active ingredient can increase secretion of mucin that is a component of lacrimal fluid the following specifically describes the present invention by referring to examples but the present invention is not limited to these examples in order to examine an effect of compound 1 on an amount of muc5ac secretion ex vivo experiments were carried out using a conjunctival tissue from a white rabbit slc jw cskslc nzw strain specifically a trephine with a diameter of 3 mm was used to sample a conjunctival tissue from a white rabbit next the tissue sample was soaked in an hbss containing 100 u03bcm of compound 1 for 90 minutes 3 hours 6 hours or 12 hours the conjunctival tissue of the control group was soaked in an hbss having a physiological saline with a volume equal to that of compound 1 after the conjunctival tissue was soaked for a predetermined time its culture supernatant was collected for each group the experiment was performed at n 5 the amount of muc5ac included in the culture supernatant was detected using the following assay first the culture supernatant of the conjunctival tissue of the control group was diluted using an hbss and a.