Objective: To establish a method to determine four components in the child phenobarbital tablet.
Methods: Ultraviolet spectrophotometry was used to determine four components without separation.
Results: The contents of aspirin, phenacetin, caffeine and phenobarbital could be measured simultaneously. The average recoveries of four components in simulated samples and the compound child phenobarbital tablet samples were 99.0%, 98.9%, 99.8%, and 101%, respectively, and relative standard deviations of those were 2.0%, 2.0%, 2.9%, and 2.2%, respectively.
Conclusion: The method is simple, fast, reliable, and can be used to monitor the quality of compound drugs.