title: [Effect of admixture of betamethasone butyrate propionate ointment on preservative efficacy].
abstract: Twenty percent of dermatologists have experienced a separation of water or deterioration of topical corticosteroids mixed with commercially available ointments and/or creams. However, few investigations of this deterioration of admixtures have been reported. To assess the effects of preservatives in preventing microbial contamination of these admixtures, we attempted to investigate the concentration of preservative agents in admixtures and the microbial contamination of these admixtures with a topical corticosteroid ointment (Antebate). The concentration of parabens was reduced by half using an admixture of corticosteroid ointment with four types of moisturizing creams, Urepearl, Pastaronsoft, Hirudoid, and Hirudoidsoft. After a further 3 months, no decrease in parabens was seen. No microbial contamination was found in any admixture stored at room temperature for 1 week and touched two times daily with a finger. The concentration and ratio of the parabens in the aqueous phase and oil phase were entirely different in the admixtures before being centrifuged. The aqueous phase of the admixtures of the oil/water (O/W)-type emulsions of Urepearl and Hirudoid was not found to have microbial contamination immediately after being centrifuged. All aqueous phases stored at room temperature or in a refrigerator for 1 week and touched with a finger twice daily exhibited microbial contamination. These experiments demonstrated that O/W-type emulsions, in which the water easily separates from the bases, should be thoroughly mixed to prevent microbial contamination.
authors.affiliation: Department of Hospital Pharmacy, Tokyo Postal Services Agency Hospital, 2-14-23 Fujimi, Chiyoda-ku, Tokyo 102-8798, Japan. mootani@tpth.go.jp
authors.forename: Michiteru
authors.initials: M
authors.lastname: Ohtani
authors.forename: Tatsurou
authors.initials: T
authors.lastname: Nakai
authors.forename: Kouji
authors.initials: K
authors.lastname: Ohsawa
authors.forename: Soan
authors.initials: S
authors.lastname: Kim
authors.forename: Mika
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Takafumi
authors.initials: T
authors.lastname: Etoh
authors.forename: Satoru
authors.initials: S
authors.lastname: Kariya
authors.forename: Syoujirou
authors.initials: S
authors.lastname: Kanou
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Uchino
mesh_terms: D001623:Betamethasone / Q000031:analogs & derivatives*; D004340:Drug Contamination / Q000517:prevention & control*; D004355:Drug Stability; D004356:Drug Storage; D004655:Emulsions; D009824:Ointments; D010226:Parabens / Q000032:analysis; D011310:Preservatives, Pharmaceutical / Q000032:analysis
chemical_list: D004655:Emulsions; D009824:Ointments; D010226:Parabens; D011310:Preservatives, Pharmaceutical; C000612965:betamethasone butyrate propionate; C011175:betamethasone-17,21-dipropionate; D001623:Betamethasone