- High performance liquid chromatographic determination of oxeladin citrate and oxybutynin hydrochloride and their degradation products
-
Two high performance liquid chromatographic (HPLC) methods are presented for the determination of oxeladin citrate (OL) and oxybutynin hydrochloride (OB) and their degradation products. The first method was based on HPLC separation of OL from its degradation product using a Nucleosil C18 column with a mobile phase consisting of acetonitrile -0.1% phosphoric acid (60:40 v/v). The second method was based on HPLC separation of OB from its degradation product using a VP-ODS C18 column with a mobile phase consisting of acetonitrile/0.01:M potassium dihydrogen phosphate/diethylamine (60:40:0.2). Quantitation was achieved with UV detection at 220:nm based on peak area. The two HPLC methods were applied for the determination of OL or OB, their degradation products, methylparaben and propylparaben in pharmaceutical preparations. The proposed methods were used to investigate the kinetics of acidic and alkaline degradation processes of OL and OB at different temperatures and the apparent pseudofirst-order rate constant, half-life and activation energy were calculated. The pH-rate profiles of degradation of OL and OB in Britton-Robinson buffer solutions within the pH range 2-12 were studied.
- El-Gindy, Alaa
-
-
Read Online
- CRYSTALLINE OXYBUTYNIN AND PROCESS FOR PREPARING THE SAME
-
The present invention relates to a crystalline oxybutynin base and process for preparing the same. Further, this invention discloses a process for preparing an acid addition salt of oxybutynin employing the crystalline oxybutynin base.
- -
-
Page/Page column 5
(2009/10/30)
-
- SUBSTITUTED PHENYLCYCLOHEXYLGLYCOLATES
-
Disclosed herein are substituted phenylcyclohexylglycolate-based muscarinic acetylcholine receptor modulators of Formula I, processes of preparation thereof, pharmaceutical compositions thereof, and methods of use thereof.
- -
-
Page/Page column 52
(2009/10/06)
-
- Synthesis and biological evaluation of 12 allenic aromatic ethers
-
Twelve allenic aromatic ethers, some of them are natural products isolated from the mangrove fungus Xylaria sp. 2508 in the South China Sea, were synthesized. Their antitumor activities against KB and KBv200 cells were determined. All these compounds demonstrated cytotoxic potential, ranging from weak to strong activity. The analysis of structure-activity relationships suggested that the introduction of allenic moiety could generate or enhance cytotoxicity of these phenol compounds.
- Wang, San-yong,Mao, Wei-wei,She, Zhi-gang,Li, Chun-rong,Yang, Ding-qiao,Lin, Yong-cheng,Fu, Li-wu
-
p. 2785 - 2788
(2008/02/05)
-
- An asymmetric dihydroxylation route to (S)-oxybutynin
-
An asymmetric synthesis of (S)-oxybutynin 1 is described using the Sharpless asymmetric dihydroxylation of α-cyclohexylstyrene as the key step.
- Gupta, Priti,Fernandes, Rodney A.,Kumar, Pradeep
-
p. 4231 - 4232
(2007/10/03)
-
- Synthesis of dialkyl(4-hydroxy-2-butynyl)amines
-
2-Propynyl alcohol smoothly reacts with secondary amines and formaldehyde, following the Mannich reaction pattern and yielding the corresponding dialkyl(4-hydroxy-2-butynyl)amines.
- Chukhadzhyan,Gevorkyan,Chukhadzhyan,Shakhatuni
-
p. 1263 - 1264
(2007/10/03)
-
- Hydrolytic profile for ester- or amide-linkage by carboxylesterases pI 5.3 and 4.5 from human liver
-
Carboxylesterases (EC 3.1.1.1) from human liver were purified using Q- Sepharose, Sephadex G-150, isoelectrofocusing and Con A-Sepharose. The calculated molecular mass of the pI 5.3 enzyme was 120 kDa and 61 kDa from the results of Sephadex G-150 gel filtration and SDS-polyacrylamide gel electrophoresis (PAGE), respectively, suggesting that this enzyme is a dimer. On the other hand, carboxylesterase pI 4.5, with a molecular-mass of 64 kDa, was a monomer. The activities of both enzymes were inhibited by typical serine enzyme inhibitors. Amino acid sequence analysis of the purified enzymes pI 5.3 and 4.5 showed high homology with rabbit carboxylesterase form 1 and 2, respectively. The results also suggested that carboxylesterase pI 5.3 is identical to the deduced amino acid sequence from cDNA for HUI, and that carboxylesterase pI 4.5 is identical to the deduced amino acid sequence from the cDNA registered as human carboxylesterase (hCE-2) in GenBank. We first purified carboxylesterase pI 4.5 and investigated its hydrolytic activity upon various drugs. The two enzymes differed in substrate specificity. Prodrugs of angiotensin-converting enzyme inhibitors, such as delapril and imidapril, were converted to active metabolites by carboxylesterase pI 5.3, but not by carboxylesterase pI 4.5. The hydrolysis velocity of temocapril by carboxylesterase pI 5.3 was 12-fold faster than by carboxylesterase pI 4.5. In contrast, aspirin oxybutynin and procaine were hydrolyzed by only carboxylesterase pI 4.5. We also found that an amide- linkage in drugs, except for that in aniracetam was not a good substrate for the two enzymes. Consequently, carboxylesterases pI 5.3 and 4.5 maybe involved in the metabolism of various drugs containing an ester-linkage.
- Takai, Satomi,Matsuda, Ayuka,Usami, Yoshiko,Adachi, Tetsuo,Sugiyama, Tadashi,Katagiri, Yoshihiro,Tatematsu, Masae,Hirano, Kazuyuki
-
p. 869 - 873
(2007/10/03)
-
- Claisen Rearrangements with Mesityl Oxide Dimethyl Ketal. Synthesis of Ipsdienone, E- and E-Ocimenone, 2,6-Dimethyl-2,7-octadien-4-one and 2,6-Dimethyl-2,7-octadien-4-ol
-
4-Methyl-3-penten-2-one (mesityl oxide) dimethyl ketal was synthesized and utilizied in Claisen rearrangements with 2,3-butadien-1-ol and 2-buten-1-ol to form ipsdienone and 2,6-dimethyl-2,7-octadien-4-one, from which the ocimenones and 2,6-dimethyl-2,7-octadien-4-ol were prepared.
- Baekstroem, Peter,Stridh, Kjell,Li, Lanna,Norin, Torbjoern
-
p. 442 - 447
(2007/10/02)
-
- Action d'organometalliques fonctionnels sur les gem-aminoethers et les sels d'immonium. II. Synthese d'amines γ-fonctionnelles α-acetyleniques, α-ethyleniques Z ou E et saturees
-
α-Functional acetylenic organomagnesium compounds easily react with gem-aminoethers and immonium salts to lead to α-acetylenic γ-functional amines in good yields.By partial reduction, these amines selectively produce Z or E α-unsaturated γ-functional amines and by complete reduction, they lead to saturated γ-functional amines.
- Courtois, Gilles,Miginiac, Philippe
-
-
- Manufacture of 1-disubstituted aminoalk-2-yn-4-ols
-
The manufacture of N-disubstituted 1-aminoalk-2-yn-4-ols by reacting a secondary amine, e.g. a dialkylamine, formaldehyde and an acetylene-alcohol by a Mannich reaction, using a copper catalyst, takes place with better yield and at a higher rate if carried out in the presence of iodine or of a bromide or iodide.
- -
-
-