- Kinetics of drug release from a hyaluronan-steroid conjugate investigated by NMR spectroscopy
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The methylprednisolone steroid ester of hyaluronan was hydrolyzed under physiological conditions in vitro, and the kinetics of drug release was investigated by NMR spectroscopy. Transverse relaxation times are correlated with the molecular rotational free
- Taglienti, Anna,Sequi, Paolo,Valentini, Massimiliano
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- A methylprednisolone production process and production apparatus (by machine translation)
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The invention discloses a methylprednisolone production device, including connected according to the procedure of the reaction, shui xifu, centrifugal filtration equipment, the concentrator, [...], biological fermentation tank, drying apparatus, the drying apparatus comprises an outer cylinder, the drying cylinder, the inner cylinder; the bottom surface of the outer cylinder is provided with a motor, the rotation of the motor shaft is provided with a exhaust fan blade, type impeller, vortex impeller; exhaust fan leaf is arranged on the bottom surface of the drying cylinder between the cylinder and the outer cylinder; drum type impeller is arranged on the drying cylinder between the cylinder and an inner cylinder; vortex impeller is arranged on the bottom of the inner drum; [...] is set with infrared heating in; on the inner end center provided with a feed port; the outer tube side wall comprises an inner wall and the outer wall; the inner wall and the outer wall of the annular cavity formed between the interlayer; outlet at upper end of the sandwich cavity is provided with an annular baffle plate; the baffle plate is provided with a vent; the upper end of the baffle is provided with a rotatable air purifies the link. This invention can reduce the methylprednisolone intermediate product in the production process of the preparation time, realize methylprednisolone rapid high-quality production. (by machine translation)
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Paragraph 0075; 0097-0099; 0100; 0108; 0109; 0120; 0121
(2019/01/07)
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- Method for reducing or preventing transplant rejection in the eye and intraocular implants for use therefor
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Methods for reducing or preventing transplant rejection in the eye of an individual are described, comprising: a) performing an ocular transplant procedure; and b) implanting in the eye a bioerodible drug delivery system comprising an immunosuppressive agent and a bioerodible polymer.
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- Mucosal adhesive device for long-acting delivery of pharmaceutical combinations in oral cavity
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Mucosal adhesive devices are provided for use in the oral cavity for therapy against infections. The devices are dosage units which comprise a combination of antimicrobial agents such as antifungal agents and anti-inflammatory agents, optionally also a local anesthetic. The dosage units yield a gradual and relatively constant release of the pharmaceuticals over at least a 12-hour period.
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- High molecular weight prodrug derivatives of antiinflammatory drugs
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Compounds of the formula 1, PS - O - A - (CH2)n- B - D (1), wherein PS-O represents an alkoxide residue of any of the free hydroxy groups of a polysaccharide (PS-OH) compound with molecular weight (Mw) of from 40,000 to 5,000,000 selected from dextran, carboxymethyl dextran, diethylaminoethyl dextran, starch, hydroxyet-hyl starch, alginates, glycogen, pullullan, agarose, cellulose, chitosan, chitin and carrageenan,A is a carbonyl group or absent,n is zero or a positive integer from 1 to 14,B is oxygen, a carbonyl group, NR wherein R is hydrogen or lower alkyl, or B is absent, and, D is (i) a group of the formula:, R1 - CO - (11), wherein R1-CO- represents the acyl residue of a carboxylic acid drug (R1-COOH) used in the treatment of inflammatory disorders; or (ii) a group of the formula:, R2 - O - (12), wherein R2-O- refers to the C-21 alkoxide residue of a known antiinflammatory steroid (R2-OH) or an alkoxide residue of any other drug or medicament containing a hydroxy functional group used in the treatment of inflammatory disorders; with the proviso that when A is absent, n is 0, and B is absent, then R1-CO- is different from the acyl residue of acetylsalicylic acid;, and non-toxic pharmaceutically acceptable acid addition salts thereof;, and non-toxic pharmaceutically acceptable cation salts thereof. Such compounds are biolabile prodrugs providing controlled release and prolonged duration of action of the parent active antiinflamma-tory agents locally at the administration site after intra-articular, intra-muscular, subcutaneous or extra-dural application while at the same time being highly stable in aqueous solution in the pH range 3--5. After oral administration of such prodrugs the parent drug is liberated selectively in the terminal ileum and the colon over an extended period of time.
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- Carboxyl group catalysis of acyl transfer reactions in corticosteroid 17- and 21-monoesters
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Succinate esters, although frequently employed as water-soluble prodrugs of poorly soluble parent drugs, are not sufficiently stable to allow long-term storage in solution. Intramolecular catalysis of ester hydrolysis by the terminal succinate carboxyl group is a contributing factor to this instability. Methylprednisolone 21-succinate has recently been reported to undergo both hydrolysis and 21 ? 17 acyl migration in aqueous solutions. Intramolecular catalysis by the terminal carboxyl group is seen in both reactions, but the catalytic mechanisms are not well understood. While acyl migration can only be catalyzed via the carboxyl group acting as a general acid or general base, hydrolysis may undergo either nucleophilic or general acid-base catalysis. To gain further insight into the catalytic mechanism, hydrolysis of methyl-prednisolone 21-succinate was carried out in aniline buffers to trap any succinic anhydride (as the anilide) that would form if the catalysis were nucleophilic. The nucleophilic mechanism was shown to account for only 15-20% of the overall catalysis. Comparisons of the rates of the intramolecularly catalyzed reactions of methylprednisolone 21- and 17-succinate were made with the same reactions of methylprednisolone-21- and 17-acetate catalyzed intermolecularly by acetate ion. Interestingly, intramolecular catalysis appears to favor acyl migration over hydrolysis. Hence, the hydrolysis of methylprednisolone 21-succinate is faster in basic solutions (pH > 7.4), while acyl migration becomes the dominant reaction in the catalyzed region of the pH profile between pH 3.6 and 7.4. Arguments are presented to account for these differences in catalytic efficiency in terms of the transition-state structures for the two reactions.
- Anderson,Conradi,Lambert
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p. 604 - 610
(2007/10/02)
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- Amine containing ester prodrugs of corticosteroids
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Novel solution stable ester prodrugs of corticosteroids of the formula STR1
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- Sulfonate containing ester prodrugs of corticosteroids
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Novel solution stable ester prodrugs of corticosteroids of the formula STR1 and their salts.
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- Influence of premicellar and micellar association on the reactivity of methylprednisolone 21-hemiesters in aqueous solution
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Self-association of drug molecules at formulation concentrations can have a major impact on formulation properties. In this study a homologous series of methylprednisolone 21-hemiesters were found to undergo self-association in aqueous solution. The effect of aggregate formation on the solution degradation of these compounds was examined. To determine the nature and extent of association of these steroidal esters, partition coefficients between butyronitrile and aqueous buffer (pH 8.5) were measured as a function of ester concentration. The partitioning data were found to be consistent with dimer formation at low concentration followed by true micelle formation at higher concentration. Chain length increases favored micelle formation, but appeared to have little effect on dimerization. The first-order rate constants for ester hydrolysis and 21 → 17 acyl migration in aqueous buffer (pH 8.5) were also found to be dependent on ester concentration. The kinetic data are consistent with a model which assumes stabilization by both dimer and micelle formation, the limiting factor at high concentration being the reactivity of the ester in the micelles. The degree of stabilization due to self-association was found to increase with chain length.
- Anderson,Conradi,Johnson
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p. 448 - 454
(2007/10/02)
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- Water-soluble steroid compounds
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Beta-cyclodextrin forms a water-soluble complex or inclusion compound with steroid compounds having a molecular structure smaller than the interior cavity in the doughnut-shaped molecular structure of beta-cyclodextrin. The resulting inclusion compounds can be used for a variety of applications including aqueous topical ophthalmic preparations and topical dermatological ointments.
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