SUMMIT MEDICAL's LIPOSPERSE Rx-TO-OTC SWITCH
Executive Summary
SUMMIT MEDICAL's LIPOSPERSE Rx-TO-OTC SWITCH for use in cholecystography was approved by FDA's Division of OTC Drug Evaluation in an April 21 letter to the firm. FDA determined that "there is sufficient evidence to generally recognize hydrogenated soybean oil as safe and effective and not misbranded for use as an OTC cholecystokinetic drug product." The OTC division approved Summit Medical's petition to include "hydrogenated soybean oil (food grade, partially-hydrolyzed soybean oil with a melting point of 34-36 degrees C) in a suitable, water dispersible powder" in the final monograph for OTC cholecystokinetic drug products. Liposperse is a combination of hydrogenated soybean oil and lecithin used for gallbladder x-rays. The oral dosage is "12.4 gms hydrogenated soybean oil in a suitable, water-dispersible powder in 2-3 ounces of water 20 minutes before diagnostic gallbladder x-ray or as directed by a doctor." Summit Medical submitted its petition on March 16, 1984. In a Sept. 27, 1985 letter responding to the petition, FDA said that it needed additional data on lecithin as an emulsifying agent, as well as on other inactive ingredients, to see if they contributed to the overall cholecystokinetic effect of the product. The firm responded to FDA's comments in a Nov. 14, 1985 letter. FDA told Summit Medical that it should continue to market Liposperse as a prescription product until the notice proposing the amendment to the final monograph is published in the Federal Register. In reviewing the study submitted by the company, FDA noted that of the subjects who received Liposperse for radiographic examination, "40% of the subjects (134 visualizations recorded in a total of 330 examinations) had the cystic duct visualized." FDA continued that since "it is not possible for the cystic duct to be visualized unless there is gallbladder contraction, at least 40% of the subjects had gallbladder contraction." The agency concluded that "the submitted data are adequate to demonstrate the effectiveness of hydrogenated soybean oil in producing gallbladder contraction." The additional information provided by the firm indicated that lecithin and the other inactive ingredients did not contribute significantly to the cholecystokinetic effect of Liposperse. With the switch, two ingredients are now approved as OTC cholecystokinetic agents. The aqueous emulsion of 50% corn oil was placed in Category I in the OTC cholecystokinetic final monograph, published in the June 10, 1983 Federal Register ("The Pink Sheet" June 13, 1983, in Brief).