Reference

Effect of structural alterations on the biotransformation rate of glucocorticosteroids in rat and human liver

Effect of structural alterations on the biotransformation rate of glucocorticosteroids in rat and human liver. Andersson, P.; Lihne, M.; Thalen, A.In this study， 51372-28-2 and 51547-52-5 are also used.; Ryrfeldt, A. (Pharmacokinet. Lab., AB Draco, Lund S-221 00, Swed.). Xenobiotica, 17(1), 35-44 (English) 1987. CODEN: XENOBH. ISSN: 0049-8254. DOCUMENT TYPE: Journal CA Section: 2 (Mammalian Hormones) The effect of structural alterations on the biotransformation rate of glucocorticosteroids (GCS) by rat- and human-liver 9000-g supernatant fraction was studied. Insertion of a 16a-hydroxy group in the prednisolone (I) [50-24-8] mol. (16a-hydroxyprednisolone [13951-70-7]) decreased the rate of biotransformation. Substitution of the 16a,17a-hydroxy groups with a sym. acetal (in, for example, desonide [638-94-8]) or esp. a non-sym. acetal (in, for example, budesonide), enhanced the biotransformation rate several-fold, particularly in human liver. Differences in the rates of metab. in rat and human liver were obsd. Hydrogenation of the 1,2-double bond in prednisolone and budesonide (hydrocortisone [50-23-7] and 1,2-dihydrobudesonide [83649-24-5]) enhanced the biotransformation rate 9-fold in rat liver but only 2-fold in human liver. Fluorination of the steroid nucleus in 6a- and 9a-positions enhanced the biotransformation rate several-fold in human liver, but in rat liver fluorination marginally decreased the rate of biotransformation. These in vitro results correlate well with available data on the 1st-pass liver metab. of the studied GCS. This indicates that in vitro data can be useful in predicting oral bioavailability of GCS. .

Bioavailability and activity of topical corticosteroids from a novel drug delivery system, the aerosol quick-break foam

Bioavailability and activity of topical corticosteroids from a novel drug delivery system, the aerosol quick-break foam. Woodford, R.; Barry, B. W. (Sch. Pharm., Portsmouth Polytech., Portsmouth/Hants., Engl.). J. Pharm. Sci., 66(1), 99-103 (English) 1977.In this article, certain chemicals are used. Some of their cas registry numbers are 2002-29-1 and 22298-29-9 CODEN: JPMSAE. DOCUMENT TYPE: Journal CA Section: 63 (Pharmaceuticals) Expts. were conducted to: (a) compare the bioavailability of betamethasone benzoate [22298-29-9] in a quick-break aerosol foam and semisolid dosage forms, (b) compare the activity of betamethasone benzoate, betamethasone valerate [2152-44-5], clobetasol propionate [25122-46-7], triamcinoloneacetonide [76-25-5], desonide [638-94-8], flumethasone pivalate [2002-29-1], and hydrocortisone butyrate [6677-99-2] in foam concs., (c) assess steroid reservoir formation in skin, and (d) assess the effect of a natural moisturizer. Efficacy was detd. by a graded response 6-h occluded vasoconsitriction test with subsequent reocclusion for reservoir demonstration. Moisturizer effect was assessed by a nonoccluded vasoconstriction test using plain and Na pyrrolidone-5-carboxylate [28874-51-3]-contg. concs. on arms pretreated with water or moisturizer. The activities of betamethasone benzoate conc., collapsed foam, ointment, and gel were similar and significantly better than the activity of the cream. Clobetasol propionate was significantly better than the other medicated concs., which were equivalent. Steroid-induced blanching decreased in the presence of a moisturizer. .