We investigated whether the component in cataplasm transmitted into hemorrhoid ointment in the combined storage of hemorrhoid ointment and non-steroidal anti-inflammatory drugs (NSAIDs) cataplasm. The NSAIDs cataplasm was used as a commercially available methyl salicylate (MS reishippu “TAIHO”, MS cataplasm) and indomethacin (Catlep®, IMC cataplasm) cataplasm. In addition, the hemorrhoid ointment was in a polyethylene container with (Neriproct® ointment, DFV-L ointment) or without aluminum laminate (Posterisan® forte, HC ointment). As for the methyl salicylate, 5.68 mg / pieces in HC ointment were detected at 40 weeks of combined storage with MS cataplasm. The methyl salicylate concentration in DFV-L ointment was lower than that in HC ointment under the same conditions. On the other hand, no contamination of indomethacin in HC and DFV-L ointment was observed in the combined storage with IMC cataplasm. These results show that the methyl salicylate in cataplasm passed the polyethylene container, and provide significant information on the risk of contamination by the combined storage of cataplasm and hemorrhoid ointment.
