Reference

Effect of ointments and ointment constituents on oxidation stability of ergocalciferol

Effect of ointments and ointment constituents on oxidation stability of ergocalciferol. Yamaoka, Keiko; Matsui, Masateru; Saito, Yoshihiro; Sato, Takatoshi (Teikyo Univ. Hosp., Tokyo 173, Japan). Byoin Yakugaku, 9(1), 57-63 (Japanese) 1983. CODEN: BYYADW. DOCUMENT TYPE: Journal CA Section: 63 (Pharmaceuticals) The stability of ergocalciferol (I) [50-14-6] in an absorption and, hydrophilic ointments and 7 ointment constituents were examd.; in addn., the antioxidant activities of gallic acid derivs. for I in hydrophilic ointment were studied. Samples were exposed to air at 40° and their oxidn. stability was measured by high performance liq. chromatog. (HPLC). Several I decompn. products were detected by HPLC. The use of dual UV wavelength confirmed that peaks corresponding to I and other substances did not overlap. The amt.Several substances with their cas registry numbers 8007-43-0 and 1166-52-5 may be metioned in this study. of I in hydrophilic ointment decreased; however, that in the absorption ointment did not change. The amt. of I decreased markedly in lauromacrogol [9002-92-0] and sorbitan sesquioleate [8007-43-0]. The amt. of I decreased in proportion to the amt. of stearyl alc. [112-92-5] in the ointment, while cetanol [36653-82-4] showed the opposite behavior. The antioxidative activities of gallic acid derivs. for I in hydrophilic ointment were as follows in the order of strength: lauryl gallate [1166-52-5], isoamyl gallate [2486-02-4], Pr gallate [121-79-9], Et gallate [831-61-8], gallic acid [149-91-7]. Thus, higher alc. concns. is an important factor in the stabilization of I in ointment. .

Use of the model building technique for coconut oil oxidation

Use of the model building technique for coconut oil oxidation. Brin, E. F.; Skibida, I. P.; Reinosa, O. (Inst. Chem. Phys., Moscow 117334, USSR). Oxid. Commun., 3(3-4), 221-32 (English) 1983. CODEN: OXCODW. ISSN: 0209-4541. DOCUMENT TYPE: Journal CA Section: 17 (Food and Feed Chemistry) The model building technique is used for abtaining a math. model of coconut oil oxidn. at 140° in the presence of food antioxidants (butyloxytoluene [128-37-0], propylgallate [121-79-9], butyloxyanisole [25013-16-5]) and of a synergist (citric acid [77-92-9]). The model fit to exptl. results was verified by solving the inverse problem of chem. kinetics. Consecutive completion of the mechanism enabled obtaining an adequate model of the process. A possible set of rate consts. was obtained which permits a quant. description of the hydroperoxide accumulation kinetics in the presence of binary mixts. of phenols with citric acid.