NMR Studies of the Inclusion Complexes Between Ezetimibe and Cyclodextrins

2018 ◽  
Vol 69 (7) ◽  
pp. 1838-1841
Author(s):  
Hajnal Kelemen ◽  
Angella Csillag ◽  
Bela Noszal ◽  
Gabor Orgovan

Ezetimibe, the antihyperlipidemic drug of poor bioavailability was complexed with native and derivatized cyclodextrins.The complexes were characterized in terms stability, stoichiometry and structure using various 1D and 2D solution NMR spectroscopic techniques. The complexes were found to be of moderate stability (logK[3). The least stable inclusion complex is formed with b-cyclodextrin, while the ezetimibe-methylated-b--cyclodextrin has a 7-fold higher stability. The results can be useful to improve the poor water-solubility and the concomitant bioavailability of ezetimibe.

Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1372
Author(s):  
Chun-Yin Yang ◽  
Pao-Hsien Huang ◽  
Chih-Hua Tseng ◽  
Feng-Lin Yen

Antioxidants from plant extracts are often used as additives in skincare products to prevent skin problems induced by environmental pollutants. Artocarpus communis methanol extract (ACM) has many biological effects, such as antioxidant, anti-inflammatory, wound healing, and photoprotective effects; however, the poor water solubility of raw ACM has limited its applications in medicine and cosmetics. Topical antioxidant nanoparticles are one of the drug-delivery systems for overcoming the poor water solubility of antioxidants for increasing their skin penetration. The present study demonstrated that ACM-loaded hydroxypropyl-β-cyclodextrin and polyvinylpyrrolidone K30 nanoparticles (AHP) were successfully prepared and could effectively increase the skin penetration of ACM through changing the physicochemical characteristics of raw ACM, including reducing the particle size, increasing the surface area, and inducing amorphous transformation. Our results also revealed that AHP had significantly better antioxidant activity than raw ACM for preventing photocytotoxicity because the AHP formulation increased the cellular uptake of the ACM in UVB-irradiated HaCaT keratinocytes. In conclusion, our results suggest that AHP may be used as a good topical antioxidant nanoparticle for delivering ACM into deep layers of the skin for preventing UVB-induced skin problems.


2020 ◽  
Vol 10 ◽  
Author(s):  
Vijay Agrawal ◽  
Vipin Sharma ◽  
Pankaj Kumar Sharma

Background: Eplerenone (EPL) is a BCS class II drug, thus, having the poor water solubility. The poor water solubility of this drug leads to the poor dissolution and ultimately shows the poor bioavailability. To overcome this problem, the solid dispersion of EPL was prepared in this study. Methods: This was accomplished by using the solvent melt method as the solid dispersion technique. In this method Pluronic F-68 and F-127 was used as the carrier and different formulations were prepared using the varying in ratio of a drug and carrier (1:1, 1:2, 1:3, 1:4, 1:5). The mixture of drug solution and carrier were prepared at 70oC, using the digital magnetic stirrer. The resultant mixture was dried at 40oC in hot air oven and optimized EPL-solid dispersion was undergone for their characterization using drug content, drug entrapment efficiency (%) and drug loading content (%), Scanning Electron Microscopy (SEM), Infra-Red spectroscopy, Differential Scanning Calorimetery (DSC), stability study and in-vitro dissolution studies. Results: The result indicated that there was no interaction between EPL and Pluronics (Pluronic F-68 & F-127), and optimized formulation (P127-2) of EPL-solid dispersion have encapsulation efficiency > 95%. Experimental work also showed that optimized formulation has 31.7% of drug loading content which was greater than other existing solid dispersion having less than 30% of drug loading content. Out of different batches, the optimized batch exhibits the faster dissolution rate in comparison of other batches. It released the almost total amount of drug (98.96%) in 30 minutes. The stored ESM-solid dispersion also exhibited their remarkable stability and remains in solid state, when it was exposed to 25oC/60% relative humidity and room temperature (38ºC) for two months. Such stability was confirmed by DSC method. The DSC thermogram of optimized formulation exhibited a melting endotherm at onset temperature of 160oC, a peak temperature of 165oC and a heat of fusion of 25.68 J/gm. Simirly, DSC thermogram of physical mixture of bulk EPL/pluronic F-127 also exhibited the onset of temperature at 165oC, and a peak temperature at 171oC. Thus, result indicated that both sample showed the almost similar DSC pattern and no one sample alter their state after the treatment of temperature and humidity used in stability testing. SEM study was also performed in this research and result indicated that the particle size of optimized formulation was varied and having the irregular matrices due to porous nature of the carrier. Conclusion: Based on different findings it can be concluded that solvent melt method could be a potential method for preparing the solid dispersion of EPL like BCS class-II Drugs and will be able to solve the dissolution and solubilization related problem of poorly soluble drugs.


2015 ◽  
Vol 80 (4) ◽  
pp. 485-497 ◽  
Author(s):  
Lucreţia Udrescu ◽  
Laura Sbârcea ◽  
Adriana Fuliaş ◽  
Ionuţ Ledeţi ◽  
Titus Vlase ◽  
...  

Zofenopril calcium (ZOF)is one of the newest angiotensin converting enzyme (ACE) inhibitor, is one of the highly lipophilic newest angiotensin and with low water solubility. This research investigates the interaction between ZOF and a ?-cyclodextrin chemically modified derivative, 2-hydroxypropyl-?-cyclodextrin (HPBCD), in order to prove the formation of an inclusion complex with an enhanced water solubility profile of ZOF. In this research is reported for the first time the physicochemical characterization and the solubility profile of an inclusion complex between ZOF and HPBCD. Different spectroscopic techniques (UV absorption spectrometry, powder X-ray diffraction, attenuated total reflectance Fourier transform IR spectroscopy) were applied in order to prove the formation of the ZOF/HPBCD inclusion complex, both in water and in solid state, backed by thermal analysis (TGA/DTG/HF). The obtained results confirm that the physicochemical properties of the ZOF/HPBCD binary system, prepared using the kneading method, are different in comparison both with the parent substances and the corresponding physical mixture, thus suggesting that an inclusion complex was formed. After the formation of the inclusion complex with HPBCD, the solubility test indicated that the water solubility of ZOF was increased by 5 times.


2019 ◽  
Vol 23 (1) ◽  
pp. 2-13 ◽  
Author(s):  
Dong-Dong Zhao ◽  
Xiao-Wen Fan ◽  
He Hao ◽  
Hong-Li Zhang ◽  
Ye Guo

Hydrophobic proteins, as one of the cellular protein classifications, play an essential function in maintaining the normal life cycle of living cells. Researches on the structure and function of hydrophobic proteins promote the exploration of the causes of major diseases, and development of new therapeutic agents for disease treatment. However, the poor water solubility of hydrophobic proteins creates problems for their preparation, separation, characterization and functional studies. The temporary solubilizing tags are considered a practical strategy to effectively solve the poor water solubility problem of hydrophobic proteins. This strategy can significantly improve the water solubility of hydrophobic peptides/proteins, making them like water-soluble peptides/proteins easy to be purified, characterized. More importantly, the temporary solubilizing tags can be removed after protein synthesis, so thus the structure and function of the hydrophobic proteins are not affected. At present, temporary solubilizing tags have been successfully used to prepare many important hydrophobic proteins such as membrane proteins, lipoproteins and chaperones. In this review, we summarize the recent researches and applications of temporary solubilizing tags.


2008 ◽  
Vol 59 (6) ◽  
Author(s):  
Codruta Soica ◽  
Cristina A. Dehelean ◽  
Valentin Ordodi ◽  
Diana Antal ◽  
Vicentiu Vlaia

Birch bark contains important pentacyclic triterpens that determine an anticancer, anti-inflammatory and antiviral activity. The compounds can be extracted by simple procedures with organic solvents. The major problem of this type of triterpens is their low water solubility which can be increased by physical procedures like cyclodextrin complexation. The aim of present study was to analyse the products between birch bark extract and hydroxypropyl-g -cyclodextrin. Hydroxypropyl-g -cyclodextrin (HPGCD) was used as a host to improve its solubility in water, via inclusion complex formation. In order to obtain the inclusion complexes, 1:2 molar ratio and two preparation methods (physical mixing, kneading) were used. The inclusion complexes were analyzed by in vitro dissolution tests, thermal analysis and X-ray diffraction.


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4089
Author(s):  
Katarzyna Betlejewska-Kielak ◽  
Elżbieta Bednarek ◽  
Armand Budzianowski ◽  
Katarzyna Michalska ◽  
Jan K. Maurin

Racemic ketoprofen (KP) and β-cyclodextrin (β-CD) powder samples from co-precipitation (1), evaporation (2), and heating-under-reflux (3) were analysed using X-ray techniques and nuclear magnetic resonance (NMR) spectroscopy. On the basis of NMR studies carried out in an aqueous solution, it was found that in the samples obtained by methods 1 and 2, there were large excesses of β-CD in relation to KP, 10 and 75 times, respectively, while the sample obtained by method 3 contained equimolar amounts of β-CD and KP. NMR results indicated that KP/β-CD inclusion complexes were formed and the estimated binding constants were approximately 2400 M−1, showing that KP is quite strongly associated with β-CD. On the other hand, the X-ray single-crystal technique in the solid state revealed that the (S)-KP/β-CD inclusion complex with a stoichiometry of 2:2 was obtained as a result of heating-under-reflux, for which the crystal and molecular structure were examined. Among the methods used for the preparation of the KP/β-CD complex, only method 3 is suitable.


RSC Advances ◽  
2021 ◽  
Vol 11 (22) ◽  
pp. 13091-13096
Author(s):  
Lu Chen ◽  
Yanbin Huang

Guest polymers have significant influence on the dissolution of drug–polymer inclusion complex crystals.


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