The measurement of extra-weak chemiluminescence of 139 kinds of tablets and capsules was carried out by use of a newly devised single photoelectron counting apparatus. The tablets and capsules tested showed chemiluminescence values of 0 to 1 380 counts/10 s, 0 to 10800 counts/10s and 37 to 245000 counts/10s, at 20, 50 and 80°C, respectively. Among the drugs tested in this report, imipramine, indole, and phenothiazine derivatives showed high chemiluminescence values.
