title: Pharmaceutical studies of levothyroxine sodium hydrate suppository provided as a hospital preparation.
abstract: The levothyroxine sodium hydrate suppository (L-T4-suppository) is provided as a hospital preparation for the treatment of hypothyroid patients with dysphagia in Japan because only oral preparations of levothyroxine sodium (L-T4) are approved for the treatment of hypothyroidism. However, it has been found that serum thyroxine and triiodothyronine levels do not increase as expected with the hospital preparation, requiring a higher dosage of L-T4 in the L-T4-suppository than in the oral preparations. In this study, to determine an effective thyroid gland hormone-replacement therapy for patients with dysphagia, the pharmaceutical properties of the L-T4-suppository were investigated. Suppositories containing 300 µg L-T4 in a base of Witepsol H-15 and Witepsol E-75 (ratio of 1 : 1) were prepared according to Chiba University Hospital's protocol. Content uniformity, stability, and suppository release were tested. The L-T4-suppository had uniform weight and content. The content and release property were stable over 90 d when the L-T4-suppository was stored at 4 °C and protected from light. The release rate of L-T4 increased as pH increased. However, no L-T4 was released below pH 7.2. The release rate of L-T4 decreased as temperature decreased. These findings suggest that the low level of release of L-T4 in the rectum under physiological conditions may be the cause of the low serum thyroxine and triiodothyronine levels following L-T4-suppository administration.
authors.affiliation: Department of Practical Pharmacy, Faculty of Pharmaceutical Sciences, Chiba University.
authors.forename: Yuhei
authors.initials: Y
authors.lastname: Hamada
authors.forename: Kazushi
authors.initials: K
authors.lastname: Masuda
authors.forename: Masato
authors.initials: M
authors.lastname: Okubo
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Nakasa
authors.forename: Yuko
authors.initials: Y
authors.lastname: Sekine
authors.forename: Itsuko
authors.initials: I
authors.lastname: Ishii
mesh_terms: D004339:Drug Compounding; D065546:Drug Liberation; D004355:Drug Stability; D004356:Drug Storage; D008027:Light; D010607:Pharmacy Service, Hospital; D013488:Suppositories; D013696:Temperature; D013974:Thyroxine / Q000032:analysis / Q000737:chemistry; D014280:Triglycerides / Q000737:chemistry
chemical_list: D013488:Suppositories; D014280:Triglycerides; C009683:witepsol; D013974:Thyroxine