Reference

Pharmaceutical release from suspension ointments

Pharmaceutical release from suspension ointments. Part 23. Tests of urea and prednisolone stabilization in an oil-in-water emulsion ointment. Horsch, W.; Mende, W.; Wolf, B.; Finke, I. (Sekt. Biowissensch., Karl-Marx-Univ., Leipzig DDR-7010, Ger. Dem. Rep.). Pharmazie, 39(7), 503-4 (German) 1984. CODEN: PHARAT. ISSN: 0031-7144. DOCUMENT TYPE: Journal CA Section: 63 (Pharmaceuticals) Urea [57-13-6] is added to corticosteroid ointments to improve release and uptake by the skin. The addn. of buffers to urea-contg. solns. retarded the pH increase but did not prevent it, and increasing pH is assocd. with prednisolone (I) [50-24-8] side-chain degrdn. The addn. of triacetin [102-76-1] to an ointment contg. I and urea stabilized the pH, because of hydrolysis of the triacetin, but could not completely prevent degrdn. of I. Urea-contg. formulations had a greater decline of I release during storage than those free of urea.

Silver-modified mobile phase for normal-phase liquid chromatographic determination of prostaglandins and their 5,6-trans isomers in prostaglandin bulk drugs and triacetin solutions

Silver-modified mobile phase for normal-phase liquid chromatographic determination of prostaglandins and their 5,6-trans isomers in prostaglandin bulk drugs and triacetin solutions. Kissinger, L. D.; Robins, R. H. (Upjohn Co., Kalamazoo, MI 49001, USA). J. Chromatogr., 321(2), 353-62 (English) 1985. CODEN: JOCRAM. ISSN: 0021-9673. DOCUMENT TYPE: Journal CA Section: 64 (Pharmaceutical Analysis) Section cross-reference(s): 2 A silver-modified, normal-phase HPLC was developed for prostaglandin bulk drugs and triacetin [102-76-1] solns. AgNO3 present in the mobile phase results in high selectivity for cis/trans isomers with conventional silica columns. Prostaglandins were esterified with a-bromo-2'-acetonaphthone [613-54-7] prior to chromatog. to provide high detectability at 254 nm. For dil. triacetin solns., a sample prepn. scheme based on gravity-flow chromatog. with silica columns was developed to isolate the prostaglandin from triacetin prior to derivatization. The anal. technique was applied to triacetin solns. contg. as little as 10 mg/mL arbaprostil (I) [55028-70-1].