Physicochemical properties of tamoxifen hemicitrate sesquihydrate.
A novel modification of tamoxifen [(Z)-2-[4-(1,2-diphenyl-1-butenyl) phenoxy]-N,N-dimethylethylamine] citrate, tamoxifen hemicitrate hydrate was prepared. The crystalline form was identified and characterized by powder and single crystal X-ray diffractometries, differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and hot-stage microscopy, and its physicochemical stability was also evaluated. The results of an elemental analysis, a single crystal X-ray analysis, and the TGA suggested that the molar ratio of tamoxifen:citric acid:water was 2:1:3 indicating it to be tamoxifen hemicitrate sesquihydrate. Simultaneous XRD-DSC measurements also indicated that two hydrates, sesquihydrate and hemihydrate, and an anhydrous form would exist during heating. The physicochemical stability of tamoxifen citrate forms A and B suspended in water and of form A during kneading and drying suggested that tamoxifen citrate was transformed into tamoxifen hemicitrate hydrate in water within 24 h, whereas tamoxifen citrate in a mixture with microcrystalline cellulose was quite stable during kneading. These results suggested that water and a mixture of water and organic solvent should be used for the manufacturing process with special attention paid to the transformation to tamoxifen hemicitrate sesquihydrate, because it showed a different stoichiometry from the active ingredient, tamoxifen citrate.
Department of Pharmaceutical Technology, Kobe Pharmaceutical University, Higashinada, Kobe 658-8558, Japan. tak_kojimajpn@yahoo.co.jp
Takashi
T
Kojima
Fumie
F
Katoh
Yoshihisa
Y
Matsuda
Reiko
R
Teraoka
Shuji
S
Kitagawa
D002152:Calorimetry, Differential Scanning; D002626:Chemistry, Pharmaceutical; D018360:Crystallography, X-Ray; D003890:Desiccation; D004355:Drug Stability; D015394:Molecular Structure; D033362:Powder Diffraction; D020845:Selective Estrogen Receptor Modulators / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013629:Tamoxifen / Q000737:chemistry*; D013678:Technology, Pharmaceutical / Q000379:methods; D013818:Thermogravimetry; D014867:Water / Q000737:chemistry
D020845:Selective Estrogen Receptor Modulators; D012997:Solvents; D014867:Water; D013629:Tamoxifen