The veterinary medicine isophen was used in this study. Isophen contains phenylbutazone as active material .Numbers of samples of isophen were prepared and were determined absorbance were determined and comparison subjected to radiation for different periods (1 ,2, 3, 4, 5) hrs. the Maximum absorbance were determined and compression Maximum absorbance's Study are performed. And ensure that the impact of irradiation on the active ingredient in the medication. The results reveal that has been reached that there is significant impact of irradiation as well as the time of irradiation on the decomposition of the active ingredient in the medication was found that with the continuation of the time of irradiation increases decomposition.