64131-97-1Relevant articles and documents
In vitro and in vivo evaluation of positively charged liposaccharide derivatives as oral absorption enhancers for the delivery of anionic drugs
Bergeon, Julie A.,Ziora, Zyta M.,Abdelrahim, Adel S.,Pernevi, Niklas U.,Moss, Anne R.,Toth, Istvan
, p. 2333 - 2342 (2010)
Oral delivery of hydrophilic, ionisable drugs remains a major challenge in drug development and a number of active pharmaceuticals fail to reach the market of oral drugs because of a lack of absorption and/or stability issues. One possible approach to improving the bioavailability of such drug candidates is to increase their lipophilicity, which is a key parameter in the permeation across cell membranes. However, modifying the chemical structure by adding lipid residues often results in changes in activity. With ionised molecules, ion-pairing can be considered to associate charged lipid moieties with the parent drug without altering its structure and therefore activity. This study presents the results of in vitro and in vivo evaluation of a series of synthetic, positively charged liposaccharide derivatives combined with an anionic model drug, piperacillin. The antimicrobial activity, plasma stability, Caco-2 cell permeability and oral absorption of the conjugates were assessed. Increases in apparent permeability were observed in vitro for three of the tested formulations, while retaining the antibacterial activity of the drug. However, the in vivo intestinal absorption of piperacillin formulated with the liposaccharide derivatives was found unchanged, possibly due to molecular dissociation, early degradation or structural differences between the intestinal epithelium and cultured monolayers.
A method for preparing paipai pulls the xilin acid (by machine translation)
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Paragraph 0028; 0030-0031; 0033-0034; 0036-0037; 0039; 0041, (2019/05/22)
The invention discloses a method for preparing paipai pulls the xilin acid. The invention is directed to preparation method in the prior existing "N - ethyl hydrogen peroxide piperazine conversion is relatively low, a condensation step the non-condensable gas carbon dioxide, solvent loss is relatively large" disadvantages, this invention adopts the pyridine in place of the triethylamine as acid, in the acylation reaction of adding triphosgene is added a catalytic amount of 4 - dimethyl amino pyridine as an initiator, can effectively improve the reaction activity of the triphosgene, so that the N - ethyl hydrogen peroxide piperazine acyl chloride conversion is improved by about 10%. The invention in the condensation reaction, binary weak alkali such as for calcium carbonate to replace the one dollar weak alkali sodium bicarbonate, help to reduce the degradation, condensation reaction yield is improved by about 5%, at the same time can reduce the generation of carbon dioxide gas causes non-condensable 50%. (by machine translation)
Preparation method of piperacillin acid
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, (2019/03/31)
The invention relates to the technical field of preparation methods of medicines and provides a preparation method of piperacillin acid, aiming at the problems of an existing preparation method of lowyield and low productivity. The preparation method comprises the following steps: S1, dissolving solid phosgene; S2, carrying out silanization on dioxypiperazine; S3, carrying out acyl chlorination;S4, dissolving ampicillin trihydrate; S5, carrying out condensation reaction; S6, carrying out hydrolysis reaction. According to the preparation method, a side chain of the piperacillin acid is formedthrough the silanization of the dioxypiperazine and the acyl chlorination; then the side chain and the ampicillin trihydrate are condensed to form piperacillin; meanwhile, rare-earth metal platinum is added into the condensation reaction and is used as a catalyst; only a trace amount of the catalyst needs to be added and a good catalysis effect can be realized, so that a reaction speed is increased; meanwhile, the purity and yield of the condensation reaction are easy to improve, so that the yield and purity of the piperacillin acid which is finally obtained through hydrolysis are easy to improve.
