- Different approaches in Partial Least Squares and Artificial Neural Network models applied for the analysis of a ternary mixture of Amlodipine, Valsartan and Hydrochlorothiazide
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Different chemometric models were applied for the quantitative analysis of Amlodipine (AML), Valsartan (VAL) and Hydrochlorothiazide (HCT) in ternary mixture, namely, Partial Least Squares (PLS) as traditional chemometric model and Artificial Neural Networks (ANN) as advanced model. PLS and ANN were applied with and without variable selection procedure (Genetic Algorithm GA) and data compression procedure (Principal Component Analysis PCA). The chemometric methods applied are PLS-1, GA-PLS, ANN, GA-ANN and PCA-ANN. The methods were used for the quantitative analysis of the drugs in raw materials and pharmaceutical dosage form via handling the UV spectral data. A 3-factor 5-level experimental design was established resulting in 25 mixtures containing different ratios of the drugs. Fifteen mixtures were used as a calibration set and the other ten mixtures were used as validation set to validate the prediction ability of the suggested methods. The validity of the proposed methods was assessed using the standard addition technique.
- Darwish, Hany W.,Hassan, Said A.,Salem, Maissa Y.,El-Zeany, Badr A.
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- Metal-free oxidative cyclization of 2-amino-benzamides, 2-aminobenzenesulfonamide or 2-(aminomethyl)anilines with primary alcohols for the synthesis of quinazolinones and their analogues
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A general metal-free oxidative cyclization process has been developed for the synthesis of quinazolinones, benzothiadiazines and quinazolines. By this protocol, a range of substituted 2-aminobenzamides, 2-aminobenzenesulfonamide and 2-(aminomethyl)anilines react with various alcohols, leading to the desired annulated products smoothly. This protocol features many advantages as broad substrate scope, mild reaction conditions, low environmental pollution, high atom-economy and good to excellent yields.
- Sun, Jinwei,Tao, Tao,Xu, Dan,Cao, Hui,Kong, Qinggang,Wang, Xinyu,Liu, Yun,Zhao, Jianglin,Wang, Yi,Pan, Yi
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p. 2099 - 2102
(2018/05/04)
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- Synthesis method of hydrochlorothiazide
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The invention relates to a synthesis method of hydrochlorothiazide. The synthesis method of the hydrochlorothiazide comprises the following steps: taking chlorothiazide as a reactant; carrying out reduction reaction under the action of organic acid and a hydroboration reagent, so as to generate a hydrochlorothiazide crude product. Borohydride is used as a reducing agent and is used for reducing acarbon-nitrogen double bond in chlorothiazide to generate hydrochlorothiazide; in a whole process, no formaldehyde or analogue participates in, so that compared with an existing synthesis method, thesynthesis method is safer and more environmentally friendly; the yield and purity of the synthesis method are improved.
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Paragraph 0063; 0067-0069; 0075; 0081; 0088; 0095; 0101
(2018/11/03)
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- A convenient and mild cyclocondensation using water-soluble aldehydes in water
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The use of negatively charged aluminosilicate layers and Lewis acidic cations embedded therein allowed efficient cyclocondensation of bisamines with water-soluble aldehydes to be achieved in water. The protocol does not involve acidic or reflux conditions, thereby avoiding undesired byproduct formation. The use of water as a reaction medium is indispensable to ensure high reaction yields.
- Kitanosono, Taku,Cho, Soo Min,Kobayashi, Shū
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p. 7237 - 7241
(2018/11/21)
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- A method for production of hydrogen chlorothiazide
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The invention belongs to the technical field of medicine production, and particularly relates to a production method for hydrochlorothiazide. Hydrochlorothiazide is prepared by using 4-amino-6-chloro-1,3-benzenedisulfonamide and formaldehyde as raw materials, reacting for 0.5-1.5 hours at a temperature of 90-100 DEG C; cooling a reaction liquid, de-coloring and adjusting a pH value to 5.5-7.0, and carrying out separation and purification. The production method is simple in process and suitable for industrialized production. The whole process is carried out in an aqueous phase; reaction conditions are mild; security coefficient is greatly increased; production period is short and is largely controlled at about 50 hours; the whole production process has small pollution to the environment; and the purity of the synthetic hydrochlorothiazide is high.
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Paragraph 0027-0030
(2017/03/08)
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- A process for the preparation of hydrogen chlorothiazide (by machine translation)
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The invention belongs to the field of medical technology, in particular to a method for production of hydrogen of DCT, to 4-amino-6-chloro -1,3-benzene sulfonamide and formaldehyde as raw materials, and ammonia and for refining of sodium hydroxide, the production process is simple, and is suitable for industrial production, the obtained hydrochiorothiazide high purity, accords with the medical requirement. (by machine translation)
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Paragraph 0014-0015
(2017/03/08)
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- Synthesis and hydrolysis kinetic study of few co-drugs of propranolol and other antihypertensive drugs
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The different acyl halide analogs of propranolol were synthesized by reacting Propanolol with different acyl anhydrides in toluene medium. The derivatives were reacted with thionyl chloride to get propranolol hemi acyl chloride. Finally the co-drugs were synthesized by reacting propranolol hemi acyl chloride with different classes of antihypertensive drugs like Nifedepine (PSN,PMN,PPN), Hydrochlorthiazide (PSH, PMH, PPH) and Acetazolamide(PSA, PMA, PPA) by ester linkage. The structure of the synthesized derivative of propranolol analogs were confirmed by M P, TLC, IR and NMR data.
- Baidya, Mayukh,Das, Amit Kumar
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body text
p. 173 - 178
(2012/01/13)
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- A PROCESS FOR PREPARATION OF HIGHLY PURE HYDROCHLOROTHIAZIDE
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The present invention relates to an improved process for the preparation of Hydrochlorothiazide of formula (I) having purity of at least 99.9% and OVI content below detectable limit. The present invention further provides a new polymorphic form of Hydrochlorothiazide. (Formula I).
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Page/Page column 9
(2010/01/07)
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- A NOVEL PROCESS FOR PREPARATION OF HIGHLY PURE CRYSTALLINE HYDROCHLOROTHIAZIDE
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This invention relates to a process for the preparation and purification of a pure crystalline Hydrochlorothiazide with overall purity 99.9% or greater and single impurity below 0.1%. This is a two step process. In first step crude hydrochlorothiazide is prepared which is in second step purified to get highly pure crystalline hydrochlorothiazide.
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Page/Page column 7
(2008/06/13)
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- Retard form of pharmaceuticals with insoluble porous diffusion coatings
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A pharmaceutical dosage unit retard form having a constant, pH-independent release rate of active ingredient, consisting of a core comprising an active ingredient, and a semi-permeable diffusion coating over the core, were the coating consists of a water-insoluble film-former, a water-soluble polymer and eventually an acid-insoluble polymer incorporated therein.
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