Powder X-ray diffraction of risedronate sodium hemipentahydrate, C_7H_(10)NNaO_7P_2(H_2O)_(2.5)

摘要

Risedronate sodium hemipentahydrate (marketed as Actonel) is an important pharmaceutical used to treat osteoporosis and Paget's disease. Commercial risedronate sodium hemipentahydrate crystallizes in the monoclinic space group I2/a (15), with a = 15.115041(28) A, b = 8.966675(16) A, c =20.60783(4) A, α = 90°, β=106.7983(2)°, γ=90°, V= 2673.830(9) A~3 , and Z=4. Previous structure determination did not include hydrogens (Gossman et al., 2003). In this work, the sample was ordered from United States Pharmacopeia (USP). The structure was solved and refined using synchrotron ( λ = 0.413914 A) powder diffraction data, and Rietveld and density functional techniques. Figure 1 shows the Powder X-ray diffraction pattern of the compound.