scholarly journals Host-guest interaction and properties of cucurbit[8]uril with chloramphenicol

2021 ◽  
Author(s):  
Lin Zhang ◽  
Jun Zheng ◽  
Guangyan Luo ◽  
Xiaoyue Li ◽  
Yunqian Zhang ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
Slow Release ◽  
In Vitro Release ◽  
Titration Calorimetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
E Coli ◽  
The Stability ◽  
Vitro Release

The interaction between cucurbit[8]uril (Q[8]) and chloramphenicol (CPE) was investigated using single-crystal X-ray diffraction, spectroscopy, isothermal titration calorimetry (ITC) and UV-Vis, NMR and IR spectroscopy. The effects of Q[8] on the stability, in vitro release performance and antibacterial activity of CPE were also studied. The results showed that CPE and Q[8] formed a 1:1 inclusion complex (CPE@Q[8]) with an inclusion constant of 5.4736 × 105 L/mol. The intervention of Q[8] did not affect the stability of CPE, but obviously reduced the release rate of CPE in artificial gastric and intestinal juice; Q[8] has a slow-release effect on CPE. The antibacterial results showed that the minimum inhibitory concentration (MIC) of CPE and CPE@Q[8] toward Escherichia coli (E. coli) was 1.5 × 10–3 and 1.0 × 10–3 mol/L, respectively, and toward Staphylococcus aureus (SA), the MIC was 2.0 × 10–3 mol/L for both CPE and CPE@Q[8]. Therefore, Q[8] enhanced the inhibitory activity of CPE against E. coli.

scholarly journals Host–guest interaction and properties of cucurbit[8]uril with chloramphenicol

2021 ◽  
Vol 17 ◽  
pp. 2832-2839
Author(s):  
Lin Zhang ◽  
Jun Zheng ◽  
Guangyan Luo ◽  
Xiaoyue Li ◽  
Yunqian Zhang ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
Slow Release ◽  
In Vitro Release ◽  
Titration Calorimetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
E Coli ◽  
The Stability ◽  
Vitro Release

The interaction between cucurbit[8]uril (Q[8]) and chloramphenicol (CPE) was investigated using single-crystal X-ray diffraction spectroscopy, isothermal titration calorimetry (ITC) and UV–vis, NMR and IR spectroscopy. The effects of Q[8] on the stability, in vitro release performance and antibacterial activity of CPE were also studied. The results showed that CPE and Q[8] formed a 1:1 inclusion complex (CPE@Q[8]) with an inclusion constant of 5.474 × 105 L/mol. The intervention of Q[8] did not affect the stability of CPE, but obviously reduced the release rate of CPE in artificial gastric and intestinal juice; Q[8] has a slow-release effect on CPE. The antibacterial results showed that the minimum inhibitory concentration (MIC) of CPE and CPE@Q[8] toward Escherichia coli (E. coli) was 1.5 × 10–3 and 1.0 × 10–3 mol/L, respectively, and toward Staphylococcus aureus (S. aureus), the MIC was 2.0 × 10–3 mol/L for both CPE and CPE@Q[8]. Therefore, Q[8] enhanced the inhibitory activity of CPE against E. coli.

scholarly journals Design and evaluation of Pulsatile drug delivery of Losartan Potassium

2014 ◽  
Vol 12 (2) ◽  
pp. 119-123
Author(s):  
MS Ashwini ◽  
Mohammed Gulzar Ahmed
Keyword(s):  
In Vitro Release ◽  
Losartan Potassium ◽  
Stability Studies ◽  
In Vitro Drug Release ◽  
Drug Content ◽  
Weight Variation ◽  
Release Studies ◽  
The Stability ◽  
Vitro Release

The study was designed for the investigation of pulsatile device to achieve time or site specific release of Losartan potassium based on chronopharmaceutical considerations. The basic design involves the preparation of cross linked hard gelatin capsules by using formaldehyde, then the drug diluent mixture were prepared and loaded in, which was separated by using hydrogel plugs of different polymers of different viscosities. Prepared formulations were subjected to evaluation of various parameters like weight variation, percentage drug content, in vitro drug release and stability studies. Weight variation and percentage drug content results showed that they were within the limits of official standards. The in-vitro release studies revealed that the capsules plugged with polymer HPMC showed better pulsatile or sustained release property as compared to the other formulations. The stability studies were carried out for all the formulations and formulations F1 & F2 were found to be stable. Dhaka Univ. J. Pharm. Sci. 12(2): 119-123, 2013 (December) DOI: http://dx.doi.org/10.3329/dujps.v12i2.17610

NOVEL PHARMACEUTICAL COCRYSTAL OF TELMISARTAN AND HYDROCHLOROTHIAZIDE

2020 ◽  
pp. 104-112
Author(s):  
ALPANA KULKARNI ◽  
SWAPNIL SHETE ◽  
VISHAL HOL ◽  
RITESH BACHHAV
Keyword(s):  
Maximum Yield ◽  
In Vitro Release ◽  
Active Pharmaceutical Ingredient ◽  
Flow Properties ◽  
Acidic Group ◽  
X Ray ◽  
Poorly Soluble ◽  
Pharmaceutical Cocrystal ◽  
Vitro Release

Objective: Telmisartan (TEL), commonly used antihypertensive, is poorly soluble in water and has limited and variable bioavailability. Commercially, TEL is available as a single drug and in combination with hydrochlorothiazide (HYZ). Researchers have developed cocrystals of TEL with coformers, namely, oxalic acid, glutaric acid, and saccharin. An attempt was made to prepare the cocrystals of TEL with HYZ, an active pharmaceutical ingredient (API) itself so that both the APIs are available in a single tablet. The present study was aimed at enhancement in solubility of TEL by formation of its cocrystals. Methods: The cocrystals of TEL with HYZ, in different stoichiometric ratios (1:0.5, 1:1, and 1:2), were prepared by solvent coevaporation and liquid-assisted grinding methods. The cocrystals, consisting of TEL:HYZ (in 1:0.5 ratio and 1:1 ratio), depicted maximum yield, drug content, saturation solubility, and flow properties. These cocrystals were characterized by X-ray analysis, infrared spectroscopy, and thermal analysis. Results: The crystal structure of TEL-HYX revealed that it was a cocrystal, since no proton was transferred between the TEL and HYZ molecules. It was predicted that two molecules are associated through a hydrogen bond between an acidic group of TEL and sulfonamido group of HYZ. The cocrystallization improved the solubility of TEL 7 times. In vitro release rate of tablets of cocrystals was higher than that of marketed TEL tablets. HYZ has a potential to form the cocrystals of TEL. Conclusion: The objective of improvement in the solubility of TEL was successfully achieved by the formation of cocrystals of TEL: HYZ.

Synthesis and Structures of Halo-Substituted Aroylhydrazones with Antimicrobial Activity

2012 ◽  
Vol 65 (4) ◽  
pp. 343 ◽  
Author(s):  
Mei Zhang ◽  
Dong-Mei Xian ◽  
Hai-Hua Li ◽  
Ji-Cai Zhang ◽  
Zhong-Lu You
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Inhibitory Concentration ◽  
Antimicrobial Activities ◽  
X Ray Diffraction ◽  
X Ray ◽  
E Coli ◽  
Diphenyl Tetrazolium Bromide

A series of new halo-substituted aroylhydrazones have been prepared and structurally characterized by elemental analysis, 1H NMR, 13C NMR, and IR spectra, and single crystal X-ray diffraction. The compounds were evaluated for their antibacterial (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas fluorescence) and antifungal (Candida albicans and Aspergillus niger) activities by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) method. Among the tested compounds, N′-(2-chloro-5-nitrobenzylidene)-2-fluorobenzohydrazide showed the most effective antimicrobial activity with minimum inhibitory concentration values of 0.82, 2.5, 1.7, 15.2, and 37.5 μg mL–1 against B. subtilis, S. aureus, E. coli, P. fluorescence, and C. albicans, respectively. The biological assay indicated that the presence of the electron-withdrawing groups in the aroylhydrazones improved their antimicrobial activities.

scholarly journals 75 Evaluating the in vitro release of essential oils from microparticles in simulated swine gastric and intestinal fluids and the essential oil stability in microparticles during feed pelleting process

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 70-70
Author(s):  
Janghan Choi ◽  
Lucy Wang ◽  
Joshua Gong ◽  
Ludovic Lahaye ◽  
Song Liu ◽  
...  
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
In Vitro Release ◽  
Oil Stability ◽  
Positive Effects ◽  
Intestinal Fluids ◽  
Gastric Fluids ◽  
The Stability ◽  
Vitro Release

Abstract Essential oils are defined as plant-derived natural bioactive compounds with positive effects on animal growth and health due to their antimicrobial and antioxidative properties. However, essential oils are very volatile, can evaporate rapidly and be rapidly absorbed in the upper gastrointestinal tract. In addition, due to their labile nature, the stability of essential oils during feed processing is often questionable, leading to variable final concentrations in feeds. Micro-encapsulation has become one of the most popular methods to deliver essential oils into the lower gut. The objective of the present study was double: 1) to validate and demonstrate the slow release of essential oils, such as thymol, micro-encapsulated in combination with organic acids in a matrix of triglycerides, in simulated swine gastric and intestinal fluids and 2) to evaluate the essential oil stability in the microparticles during feed pelleting process. In the in vitro release experiments, the microparticles were incubated in simulated gastric fluids for 2 hours and then the samples were incubated in simulated intestinal fluids for 0, 1, 2, 3, 4, 6, 8, 10, and 24 hours at 39°C. In the pelleting experiment, a wheat-corn basal diet with 2 kg of micro-encapsulated product was formulated and pelleted. The thymol content in the samples was analyzed by gas chromatography with flame-ionization detection. The results showed that 27.65% thymol was released in simulated gastric fluids and the rest of thymol was progressively released in intestinal fluids until completion, which was achieved by 24 hours. The thymol concentration was not significantly different between the mash feeds and pelleted feeds (P > 0.05). In conclusion, the micro-encapsulated organic acid and essential oil product was able to maintain the stability of thymol under a commercial pelleting process and allow a slow and progressive release of its active ingredients as thymol in simulated digestive fluids.

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