- Synthesis technology of amlodipine maleate
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The invention discloses a synthesis technology of amlodipine maleate and relates to the technical field of medicine synthesis, aiming at solving the problem in an existing synthesis technology that more byproducts and impurities exist in industrial production. By controlling parameters of the synthesis technology and reducing the content of the impurities, the purity of the prepared amlodipine maleate reaches 99.5 percent; the self-made amlodipine maleate is used as a raw material for further preparing the amlodipine maleate, so that the cost of a product is reduced and the quality controllability of the product is strong.
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- The effect of ion pairing on the skin permeation of amlodipine
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The purpose of the present study was to evaluate the effect of ion pairing on the skin permeation of amlodipine. Amlodipine base (AM) was first prepared from amlodipine besilate (AM-B), then amlodipine adipate (AM-A), amlodipine oxalate (AM-O) and amlodipine maleate (AM-M) were prepared using AM and the corresponding organic acids. Differential scanning calorimetry (DSC) thermogram studies demonstrated the formation of complexes between AM and the various acids. In vitro percutaneous absorption of AM and its complexes was evaluated through excised rat skin using 2-chamber diffusion cells. The results showed that AM had the greatest steady-state flux and lowest permeability coefficient of the five compounds from the El system (ethanol : isopropyl myristate (IPM) = 2:8), and its four complexes all exhibited a lower flux and higher permeability coefficient than AM.
- Jiang, Yuxuan,Fang, Liang,Niu, Xicao,Ma, Rui,He, Zhonggui
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experimental part
p. 356 - 360
(2009/04/04)
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- PROCESS FOR THE PREPARATION OF AMLODIPINE SALTS
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A process for the preparation of salts of amlodipine comprises subjecting a compound of formula (II) to a deprotection reaction and converting the amlodipine free base thus obtained to a salt (1) without isolating amlodipine free base. Preferably, the maleate, besylate, malate or fumarate salt is made.
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Page/Page column 11-12
(2008/06/13)
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- ISOLATION OF DIHYDROPYRIDINE DERIVATIVE AND PREPARATION SALTS THEREOF
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The title compound is isolated in pure form by using a crystallization process and converted to its pharmaceutically acceptable salts. The crystallization process affects stability and purity of the amlodipine salts. All known impurities and one unknown impurity, which forms during the synthesis of the amlodipine salts, were isolated, characterized, and synthesized. A new method allowing the quantitative HPLC analysis of all related impurities of amlodipine salts in a single chromatogram was developed.
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- Process for making amlodipine
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Amlodipine and related analogues thereof are prepared by the following general reaction scheme: R1and R2each independently represent a C1-C4alkyl group. The process provides for the formation of compounds of formula (1) in good yield and purity. Further, the compounds of formula (1) can be used as calcium channel blockers or as reference standards or reference markers for checking the purity of amlodipine.
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- Process for making amlodipine maleate
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A process for making amlodipine maleate comprises reacting amlodipine or an acid addition salt thereof with maleic acid under an acidic environment to form an amlodipine maleate product. The process allows for the formation of amlodipine maleate substantially free from amlodipine aspartate.
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- Process for making amlodipine, derivatives therof, and precursors therefor
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Amlodipine and related analogues thereof are prepared by the following general reaction scheme: R1 and R2 each independently represent a C1-C4 alkyl group. The process provides for the formation of compounds of formula (1) in good yield and purity. Further, the compounds of formula (1) can be used as calcium channel blockers or as reference standards or reference markers for checking the purity of amlodipine.
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- Process for making amlodipine maleate
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A process for making amlodipine maleate comprises reacting amlodipine or an acid addition salt thereof with maleic acid under an acidic environment to form an amlodipine maleate product. The process allows for the formation of amlodipine maleate substantially free from amlodipine aspartate.
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- 2-(SECONDARY AMINOALKOXYMETHYL) DIHYDROPYRIDINE DERIVATIVES AS ANTI-ISCHAEMIC AND ANTIHYPERTENSIVE AGENTS
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A dihydropyridine compound of the formula or a pharmaceutically acceptable acid addition salt thereof, wherein Y is -(CH2)2-, -(CH2)3-, -CH2CH(CH3)-or -CH2C(CH3)2-; R is aryl or heteroaryl; R1 and R2 are each independently C1-C4 alkyl or 2-methoxyethyl; and R3 is hydrogen, C1-C4 alkyl, 2-(Ci-C4 alkoxy)ethyl, cyclopropylmethyl, benzyl, or -(CH2)mCOR4 where m is 1, 2 or 3 and R4 is hydroxy, C1-C4 alkoxy or -NR5R6 where R5 and R6 are each independently hydrogen or C1-C4 alkyl can be employed for treating or preventing a heart condition or hypertension.
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- Dihydropyridines
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Dihydropyridine anti-ischaemic agents of the formula: STR1 and their salts where R is aryl or heteroaryl, R1 and R2 are each C1 -C4 alkyl or 2-methoxyethyl, Y is --(CH2)n -- where n is 2, 3, or 4 and is optionally substituted by 1 or 2 CH3 groups, and R3 is an optionally substituted 5- or 6-membered heterocyclic group attached to the adjacent N atom by a C atom, said group R3 being optionally fused to a further heterocyclic group or to a benzene ring.
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