Absorption of steroids

I Komiya, JY Park, A Kamani, NFH Ho, WI Higuchi. Physical model studies on the simultaneous fluid flow and absorption of steroids in the rat intestines. Int J Pharm 4 249-262, 1980. 

Therapeutically effective doses of colchicine in gout are 2-3 mg per patient on day 1 with smaller doses later, and 0.5-1 mg/day for 1-3 years given orally in familial Mediterranean fever (131). Side effects such as ileal dysfunction, decreased vitamin Bi2 absorption, and an increased absorption of steroids occur after intake of 7-10 mg/day, which if continued for 4-5 days result in dehydration and renal shutdown (96). The three congeners of allocolchicine, jerusalemine, salimine, and suhailamine, which all had (—)-rotations were isolated from Colchicum decaisnei Boiss. (141). 

McKenzie AW, Staoughton RM (1962) Method for comparing the percutaneous absorption of steroids. Arch Dermatol 86 608-610... 

Siddiqui, O., Roberts, M. S., and Polack, A. E. Percutaneous absorption of steroids Relative contributions of epidermal penetration and dermal clearance. J. Pharmacokin. Biopharm. 17 405, 1989. 

McKenzie, A.W. Percutaneous absorption of steroids. Arch. Dermatol. 1962, 86, 91-94. 

McKenzie AW and Stoughton RB. Method for Comparing Percutaneous Absorption of Steroids. Arch Dermatol 1002 86 608—610. 

Bde salts, cholesterol, phosphoHpids, and other minor components are secreted by the Hver. Bile salts serve three significant physiological functions. The hydrophilic carboxylate group, which is attached via an alkyl chain to the hydrophobic steroid skeleton, allows the bile salts to form water-soluble micelles with cholesterol and phosphoHpids in the bile. These micelles assist in the solvation of cholesterol. By solvating cholesterol, bile salts contribute to the homeostatic regulation of the amount of cholesterol in the whole body. Bile salts are also necessary for the intestinal absorption of dietary fats and fat-soluble vitamins (24—26). 

Data collected on the uv spectra of steroids are available in several books, spectmm adases, and review articles (263). The most characteristic absorptions in steroid hormones include a,P-unsaturated ketones, conjugated dienes, and phenoHc A-rings (264). 

In Older to improve the poor oral absorption of carbenicillin [4697-36-3] a bpophilic rndanyl ester has been formulated, Geocillin [33331-88-3] (5). Prednisolone [30-24-8] a steroid, is derivatized to its C-21 hemisuccinate sodium salt (6) to make it extremely water-soluble (108). 

Exposure to estrogenic compounds through diet will differ for herbivores and carnivores, the latter being most likely to encounter endogenous steroids in their prey. Efficient uptake of steroids in mammals is illustrated by the use of the contraceptive pill, but routes of absorption in invertebrates remain to be determined. The relationship between endocrine disruption and metabolic toxicity, with reduced reproductive viability a secondary consequence of metabolic disturbance, also merits further study in invertebrate species. 

The NMR study of steroidal epoxides (discussed in section II-F) parallels that of the analogous thiiranes. It is possible to relate the location and configuration of the thiirane group with the angular methyl and thiirane proton resonances. The proton NMR relationships for the intermediate thiocyanatohydrins have been included inageneral NMR study of steroids. Electronic spectra may be used in the analysis of steroidal thiiranes. Spectroscopic measurements have shown the existence of a low intensity absorption in the 240-260 m region. The regular patterns of rotatory contributions of thiiranes which are comparable with those of ketones prompted an accumulation of ORD and CD data for steroidal thiiranes. 

The combined acetone extracts were extracted six times with one-fourth volume of ethylene dichloride and the ethylene dichloride extract was evaporated under vacuum to leave the steroid residue. This steroid residue was taken up in a minimum of methylene chloride and applied to the top of a column packed with 30 grams of silica which had been previously triturated with 21 ml of ethylene glycol. Then various developing mixtures, saturated with ethylene glycol, were passed over the column. Cuts were made as each steroid was eluted as determined by the lowering of the absorption of light at 240 mp on the automatic chromatographic fraction cutter. 

A Kupferman, MV Pratt, K Suckewer, HM Leibowitz. (1974). Topically applied steroids in corneal disease. III. The role of drug derivative in stromal absorption of dexamethasone. Arch Ophthalmol 91 373-376. 

A first open, uncontrolled study [46], performed in 12 patients with active IBD refractory to standard treatment who all had positive stool culture, suggested that adding rifaximin (800 mg daily) could be beneficial. A further small but controlled investigation performed in our unit [47] evaluated the efficacy and systemic absorption of rifaximin in patients with moderately to severely active UC refractory to steroid treatment. Patients were eligible if they had no response to intravenous corticosteroid therapy (methylprednisolone 1 mg/kg/day) after 7-10 days. Twenty-eight patients were randomized to receive rifaximin 400 mg b.i.d. or placebo for 10 days as an add-on... 

A. Hussain, S. Hirai, and R. Bawarshi. Nasal absorption of natural contraceptive steroids in rats-progesterone absorption. J Pharm Sci 70 466 167 (1981). 

Ocular complications following local or systemic administration of steroids include glaucoma, cataracts, adverse influence on specific ocular infections, pseudotumor cerebri, ptosis, mydriasis, subjective visual complaints, visual field defects, systemic absorption of the topical medication, conjunctival and palpebral petechiae, epithelial punctate keratitis, and, possibly, corneal and scleromalacia. ... 

Figure 2. VCD and absoiption spectra in the C O stretching region of steroid /3712, 0.026 M in CHCI3. Sample path length O.OS cm, resolution 11 cm time constant 10 s. Theoretical absorption...

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