Tongli Biomedical Co., Ltd.

Suzhou Tongli Biomedical Co., Ltd

Mingxin Qian

Rodney J Y Ho

John C Kraft, Ii

Chunsheng Qiao

Junwei Shi

Rodney Jy Ho

John C Kraft Ii

The present invention relates to lipid-associated indocyanine green particles for enhanced functional high-resolution near-infrared fluorescence medical imaging of lymphatic vessels, lymph nodes, lymphatic abnormalities, tumors, and inflammation.

Lipid nanoparticles and uses thereof

The present disclosure relates to a process and new intermediates for the synthesis of (R)-praziquantel, which is obtained through four steps in proper order, that is, condensation reaction, reduction reaction, acylation reaction and ring-closing reaction, using (1R)-2-substituted-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid as starting material. Overall, the present disclosure provides a (R)-praziquantel product with higher optical purity through a process route that is more cost effective and environmentally friendly. 

Process for the synthesis of (R)-praziquantel

The present invention relates to a crystal form of (R)-praziquantel and a preparation method and uses thereof. The X-ray diffraction pattern (CuK&#x3b1; radiation) of the crystal form of (R)-praziquantel at 25&#xb0; C. shows the following diffraction peaks: 2-Theta =6.9&#xb1;0.2&#xb0;, 8.3&#xb1;0.2&#xb0;, 15.1&#xb1;0.2&#xb0;, 17.4&#xb1;0.2&#xb0;, 19.8&#xb1;0.2&#xb0;, 21.9&#xb1;0.2&#xb0;, 24.3 &#xb1;0.2&#xb0; or d=12.74&#xb1;0.20 &#x212b;, 10.61&#xb1;0.20 &#x212b;, 5.87&#xb1;0.20 &#x212b;, 5.09&#xb1;0.20 &#x212b;, 4.48&#xb1;0.20 &#x212b;, 4.06&#xb1;0.20 &#x212b;, 3.66&#xb1;0.20 &#x212b;. Compared to the existing crystal form of praziquantel, the crystal form of the present invention has better solubility, better drug efficacy and better pharmacokinetic characteristics. The preparation method of the present invention has the following advantages: good reproducibility, environmentally friendly, low cost, and able to operate at a normal pressure and temperature, and suitable for large-scale production. 

Crystal form of (R)-praziquantel and preparation method and application thereof

Provided are R-praziquantel preparation methods, which utilize the characteristics of biological enzyme of strong stereoselectivity, site-selectivity, and regioselectivity, of high resolution efficiency, of mild reaction conditions, and of simple operations to catalyze the hydrolysis of a certain enantiomer in a chemically synthesized racemate or a derivative, thus acquiring a mixture of reacted and unreacted optical isomers. R-praziquantel prepared by the method can have a purity of 98% or more.

R-praziquantel preparation method

The invention relates to a new method for preparing (R)-praziquantel. In the invention, by taking advantage of the high stereo selectivity, site selectivity and region selectivity of an enzyme, an intermediate of a pure optical and chiral (R)-praziquantel are obtained by means of the dynamic kinetic resolution of an enantiomer from the synthesized racemate or derivatives thereof, and the (R)-praziquantel is obtained by using various conventional and mature organic chemical reactions with higher yield. The method of the invention has the potential advantages of easily available raw materials, low cost, environmentally safer process and convenience for large-scale production. Also, the purity of the end product can be more than 98%. By adopting the invention, the quality of the product is improved and a basis for developing high quality of active pharmaceutical ingredients and formulations is established, and thus the pending industrial problem of purifying praziquantel over 30 years becomes solvable.

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Jiangsu, China

Mingxin Qian