5835-79-0Relevant articles and documents
DIALKYLAMINO ALKYL ESTERS OF PIVAGABINE AS MEDICAMENTS FOR THE TREATMENT OF CENTRAL NERVOUS SYSTEM DISORDERS
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Page/Page column 74-75, (2008/12/06)
The present embodiments are related to the compound of Formula 1 or Formula 2 below and pharmaceutical formulations thereof as well as treatments for a wide variety of Central Nervous System disorders with the pharmaceutical formulations. Some embodiments include the use of a variety of the instant compounds which surprisingly and advantageously exhibit improved pharmacokinetic and therapeutic profiles in comparison to pivagabine.
Synthesis, stability studies, anti-inflammatory activity and ulcerogenicity of morpholinoalkyl ester prodrugs of niflumic acid
Talath, Sirajunisa,Gadad, Andanappa K.
, p. 744 - 752 (2007/10/03)
In search for potential prodrugs for anti-inflammatory drug candidates in the niflumate series, novel morpholinoalkyl ester prodrugs of niflumic acid (CAS 4394-00-7) 5a-b were prepared by esterification of appropriate morpholinylalkyl alcohols 3a-b with niflumic acid 4 in the presence of dicyclohexyl carbodiimide (DCC) and catalyst dimethylamino pyridine (DMAP) at 0-5°C. The structures were confirmed by elemental and spectral data (UV, IR, 1H-NMR, 13C-NMR, and EI-MS). The ester prodrugs 5a-b showed better solubility than the parent drug niflumic acid 4 in simulated gastric fluid (SGF) and phosphate buffer (pH 7.4). The in vitro hydrolysis studies were conducted at pH 1.3 (SGF), phosphate buffer (pH 7.4) and in human plasma diluted with phosphate buffer (pH 7.4) at 37 ± 0.5°C using HPLC with UV detection. The ester prodrugs 5a-b were quantitatively hydrolyzed to the parent drug niflumic acid 4 by enzymatic and/or chemical means. It is observed that an increase in the carbon chain length rendered the prodrugs 5a-b more stable in phosphate buffer (pH 7.4) than in pH 1.3 (SGF), but they were rapidly hydrolyzed in human plasma at 37 ± 0.5°C. They exhibited longer hydrolytic half-lives of 16.11-53.30 h in aqueous buffer solutions (pH 1.3 and 7.4) and 1.63-2.73 min in human plasma, respectively. The title compounds were evaluated in vivo for anti-inflammatory activity in carrageenan induced rat paw oedema model in rats at the doses 45, 90, 150 mg/kg b.w. The test compounds exhibited good anti-inflammatory activity (46.6-53.2 % at the dose of 150 mg/kg b. w.) with respect to niflumic acid (78.7 % at the dose of 90 mg/kg b.w.). The compounds were also screened for in vivo ulcerogenicity, it was observed that the prodrug 5b was significantly less irritating to gastric mucosa than compound 5a and the parent drug niflumic acid 4 following single and chronic oral administration in rats. ECV. Editio Cantor Verlag.
Piperazinylalkyl prodrugs of naproxen improve in vitro skin permeation
Rautio, Jarkko,Nevalainen, Tapio,Taipale, Hannu,Vepsaelaeinen, Jouko,Gynther, Jukka,Laine, Krista,Jaervinen, Tomi
, p. 157 - 163 (2007/10/03)
Novel morpholinyl (4a) and piperazinylalkyl (4b-e) esters were synthesized and evaluated in vitro for their properties as bioreversible topically administered dermal prodrugs of naproxen. These ionizable prodrugs exhibited various aqueous solubilities and lipophilicities, depending on the pH of medium. As indicated by octanol-buffer partition coefficients (logP(app)) at pH 7.4, all of the prodrugs were significantly more lipophilic (logP(app)=0.7-3.9) than naproxen (logP(app)=0.3). Furthermore, the most aqueous of the soluble prodrugs (4b-d) were only 2-3-fold less soluble in an aqueous buffer of pH 7.4 (~30-50 mM) than was naproxen (~100 mM). At a pH of 5.0, prodrugs showed a generally higher aqueous solubility and similar logP(app) values, compared to naproxen. The chemical and enzymatic hydrolysis of prodrugs at 37°C was investigated in aqueous buffer solutions (pH 5.0 and 7.4) and in 80% human serum (pH 7.4), respectively. The prodrugs showed moderate chemical stability (t(1/2)=15-150 days at pH 5.0), and they were hydrolyzed enzymatically to naproxen, with half-lives ranging from 0.4 to 77 min. In permeation studies using post-mortem human skin in vitro, the flux of naproxen was 6.5 and 1.6 nmol/cm2.h in a saturated aqueous buffer vehicle of pH 7.4 and 5.0, respectively. Among the prodrugs, two piperazinyl derivatives (4c and 4d) resulted in a 9- and 4-fold enhancement of permeation, respectively, when compared to naproxen itself at pH 7.4. 4c also resulted in a significantly (4-fold) better permeation than naproxen at pH 5.0. In conclusion, piperazinyl esters improved skin permeation of naproxen and are promising prodrugs of naproxen for topical drug delivery. Copyright (C) 2000 Elsevier Science B.V.
Morpholinoalkyl ester prodrugs of diclofenac: Synthesis, in vitro and in vivo evaluation
Tammara,Narurkar,Crider,Khan
, p. 644 - 648 (2007/10/02)
Morpholinoalkyl esters (HCl salts) of diclofenac (1) were synthesized and evaluated in vitro and in vivo for their potential use as prodrugs for oral delivery. Prodrugs were freely soluble in simulated gastric fluid (SGF) and pH 7.4 phosphate buffer and showed a minimum of a 2000-fold increase in solubility over the parent drug. All prodrugs were more lipophilic than 1 as indicated by n-octanol/pH 7.4 buffer partition coefficients, but less lipophilic than 1 in terms of n-octanol/SGF partition coefficients. Potentiometrically determined ionization constants (pK(a)s) were in the range of 7.52 to 8.40 at 25 °C. The chemical and enzymatic hydrolyses of prodrugs were evaluated in SGF/pH 7.4 phosphate buffer and rat plasma, respectively, at 37 °C. All prodrugs were quantitatively hydrolyzed to 1 by either chemical and/or enzymatic means. An increase in carbon chain length rendered the prodrugs more stable at pH 7.4, but less stable in SGF. In general, the esters were hydrolyzed rapidly in rat plasma at 37 °C, the half-lives of hydrolysis being in the range of 4.85 to 23.49 min. Based on in vitro results, prodrug 2 was chosen to evaluate solid-state stability, bioavailability, and in vivo ulcerogenicity. At elevated temperatures, the solid-state decomposition of 2 followed biphasic kinetics, with rapid decomposition occurring initially. The extent, but not the rate, of absorption was significantly greater in rats for prodrug 2 than 1 following single dose oral administration. Prodrug 2 was significantly less irritating to gastric mucosa than 1 following single and chronic oral administration in rats.
Omega-quaternary ammonium alkyl esters and thioesters of acidic nonsteroidal antiinflammatory drugs
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, (2008/06/13)
Quaternary ammonium alkyl esters and thioesters of acidic nonsteroidal anti-inflammatory drugs (NSAIDs) are disclosed. These esters and thioesters display the anti--inflammatory profile of the parent NSAIDs with greatly reduced gastrointestinal irritancy, providing a more favorable separation of therapeutic activity and toxicological side effects than the parent NSAIDs.
