Charge-assisted intermolecular hydrogen bond formed in coamorphous system is important to relieve the pH-dependent solubility behavior of lurasidone hydrochloride

RSC Advances ◽  
2016 ◽  
Vol 6 (108) ◽  
pp. 106396-106412 ◽  
Author(s):  
Shuai Qian ◽  
Zhen Li ◽  
Weili Heng ◽  
Shujun Liang ◽  
Di Ma ◽  
...  

In comparison to amorphous LH, coamorphous LH-REP without evidence of intermolecular hydrogen bond, exhibited greatly improved solubility with pH-dependent behavior, significantly enhanced dissolution rate and physical stability.

CrystEngComm ◽  
2020 ◽  
Vol 22 (35) ◽  
pp. 5841-5853
Author(s):  
Yi Hu ◽  
Cuiping Jiang ◽  
Bin Li ◽  
Lijing Zhou ◽  
Renjie Xu ◽  
...  

The current study was aimed at investigating the lurasidone hydrochloride–shikimic acid co-amorphous system using a new type of organic acid.


Author(s):  
Narendar D ◽  
Ettireddy S

The content of this investigation was to study the influence of β-cyclodextrin and hydroxy propyl-β-cyclodextrin complexation on enhancement of solubility and dissolution rate of isradipine. Based on preliminary phase solubility studies, solid complexes prepared by freeze drying method in 1:1 molar ratio were selected and characterized by DSC for confirmation of complex formation. Prepared solid dispersions were evaluated for drug content, solubility and in vitro dissolution. The physical stability of optimized formulation was studied at refrigerated and room temperature for 2 months. Solid state characterization of optimized complex performed by DSC and XRD studies.  Dissolution rate of isradipine was increased compared with pure drug and more with HP-β-CD inclusion complex than β-CD. DSC and XRD analyzes that drug was in amorphous form, when the drug was incorporated as isradipine β-CD and HP-β-CD inclusion complex. Stability studies resulted in low or no variations in the percentage of complexation efficiency suggesting good stability of molecular complexes. The results conclusively demonstrated that the enhancement of solubility and dissolution rate of isradipine by drug-cyclodextrin complexation was achieved.   


Author(s):  
Ganesh kumar Gudas ◽  
Manasa B ◽  
Senthil Kumaran K ◽  
Rajesham V V ◽  
Kiran Kumar S ◽  
...  

Promethazine.HCl is a potent anti-emetic. The central antimuscarinic actions of antihistamines are probably responsible for their anti-emetic effects. Promethazine is also believed to inhibit the medullary chemoreceptor trigger zone, and antagonize apomorphine -induced vomiting. Fast dissolving tablets of Promethazine.HCl were prepared using five superdisintegrants viz; sodium starch glycolate, crospovidone, croscarmellose, L-HPC and pregelatinised starch. The precompression blend was tested for angle of repose, bulk density, tapped density, compressibility index and Hausner’s ratio. The tablets were evaluated for weight variation, hardness, friability, disintegration time (1 min), dissolution rate, content uniformity, and were found to be within standard limit. It was concluded that the fast dissolving tablets with proper hardness, rapidly disintegrating with enhanced dissolution can be made using selected superdisintegrants. Among the different formulations of Promethazine.HCl was prepared and studied and the formulation S2 containing crospovidone, mannitol and microcrystalline cellulose combination was found to be the fast dissolving formulation. In the present study an attempt has been made to prepare fast dissolving tablets of Promethazine.HCl, by using different superdisintegrants with enhanced disintegration and dissolution rate. 


2021 ◽  
Author(s):  
Shu bin Li ◽  
Xiao Wang ◽  
Jiang Zhu ◽  
Zhenyu Wang ◽  
Lu Wang

In this work, using carboxyl-modified Fe3O4 nanoparticles as a photothermal agent, combining the chemical amide bond and intermolecular hydrogen bond crosslinking force, a photothermal hydrogel with enhanced mechanical properties was...


2017 ◽  
Vol 43 (9) ◽  
pp. 1430-1439 ◽  
Author(s):  
Ebtessam A. Essa ◽  
Amira O. Elmarakby ◽  
Ahmed M. A. Donia ◽  
Gamal M. El Maghraby

1985 ◽  
Vol 63 (11) ◽  
pp. 2915-2921 ◽  
Author(s):  
Ian M. Piper ◽  
David B. MacLean ◽  
Romolo Faggiani ◽  
Colin J. L. Lock ◽  
Walter A. Szarek

The products of a Pictet–Spengler condensation of tryptamine and of histamine with 2,5-anhydro-D-mannose have been studied by X-ray crystallography to establish their absolute configuration. 1(S)-(α-D-Arabinofuranosyl)-1,2,3,4-tetrahydro-β-carboline (1), C16H20N20O4, is monoclinic, P21 (No. 4), with cell dimensions a = 13.091(4), b = 5.365(1), c = 11.323(3) Å, β = 115.78(2)°, and Z = 2. 4-(α-D-Arabinofuranosyl)imidazo[4,5-c]-4,5,6,7-tetrahydropyridine (3), C11H17N3O4, is orthorhombic, P212121 (No. 19), with cell dimensions a = 8.118(2), b = 13.715(4), c = 10.963(3) Å, and Z = 4. The structures were determined by direct methods and refined to R1 = 0.0514, R2 = 0.0642 for 3210 reflections in the case of 1, and to R1 = 0.0312, R2 = 0.0335 for 1569 reflections in the case of 3. Bond lengths and angles within both molecules are normal and agree well with those observed in related structures. In 3 the base and sugar adopt a syn arrangement, which is maintained by an internal hydrogen bond between O(2′) and N(3). The sugar adopts a normal 2T3 twist conformation. The sugar has the opposite anti arrangement in the β-carboline 1 and the conformation of the sugar is unusual; it is close to an envelope conformation with O(4′) being the atom out of the plane. This conformation is caused by a strong intermolecular hydrogen bond from O(5′) in a symmetry-related molecule to O(4′). Both compounds are held together in the crystal by extensive hydrogen-bonding networks. The conformations of the compounds in solution have been investigated by 1H nmr spectroscopy, and the results obtained were compared with those obtained by X-ray crystallography for 1 and 3.


2021 ◽  
Author(s):  
Huamei Chen ◽  
Guangyuan Feng ◽  
Qiu Liang ◽  
Enbing Zhang ◽  
Yongtao Shen ◽  
...  

Herein, we illustrate how the cooperation of intermolecular hydrogen bonds and conformation flexibility leads to the formation of diverse complex covalent nanostructures on the surface, while the relative abundance of...


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