Crystal forms of ketorolac.
Four crystal forms of ketorolac have been obtained by recrystallization in organic solvents under variable conditions. Different ketorolac polymorphs and pseudopolymorph were characterized by X-ray powder diffraction crystallography (XRD), Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). In the dissolution studies in water at 37 +/- 0.5 degrees C, four crystal forms showed different patterns. The solubility of Form I were the highest. The solubility decreased in rank order: Form I > Form II > Form III > Form IV. Form land Form III were shown to have a good physical stability at room temperature for 60 days. However, Form II is converted to Form III and Form IV is converted to Form I after 60 days storage. Therefore, these observations indicate that crystalline polymorphism for ketorolac is readily inter-convertible and the relationship may have to taken into consideration in the formulation of the drug.
Sohn
Young-Taek
YT
College of Pharmacy, Duksung Women's University, Seoul 132-714, Korea. ytsohn@duksung.ac.kr
Seo
Hyun Ok
HO
D002626:Chemistry, Pharmaceutical; D003460:Crystallization; D020910:Ketorolac / Q000737:chemistry / Q000493:pharmacokinetics*; D012995:Solubility; D014961:X-Ray Diffraction / Q000379:methods
D020910:Ketorolac