title: Colorimetric prednisolone assay and its application to dissolution studies.
abstract: The colorimetric method of Porter and Silber, originally developed for assaying cortisone and related corticosteroids, was adapted to the assay of prednisolone in the presence and absence of a surfactant, octoxynol 9. Optimal conditions for the colorimetric reaction between prednisolone and acidified phenylhydrazine solution were 30 min at 50 degrees C. The slight interference of octoxynol 9 with the absorbance of the yellow prednisolone-phenylhydrazine complex at 410 nm was corrected by adding an equal surfactant concentration to the blank. When freshly prepared acidified phenylhydrazine solutions were used, the colorimetric method had a sensitivity of 0.2 microgram/mL and a precision of 0.1 microgram/mL. Its averaged relative standard deviation was 3.7% in the prednisolone concentration range of 10-300 micrograms/mL.
mesh_terms: D003124:Colorimetry / Q000379:methods; D004355:Drug Stability; D017830:Octoxynol; D010659:Phenylhydrazines; D011092:Polyethylene Glycols; D011239:Prednisolone / Q000032:analysis*; D012995:Solubility; D013607:Tablets / Q000032:analysis; D013696:Temperature; D013997:Time Factors
chemical_list: D010659:Phenylhydrazines; D013607:Tablets; D011092:Polyethylene Glycols; D017830:Octoxynol; D011239:Prednisolone