scholarly journals pH-Sensitive Glycyrrhizin Based Vesicles for Nifedipine Delivery

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1270
Author(s):  
Olga Yu. Selyutina ◽  
Anna V. Mastova ◽  
Ekaterina A. Shelepova ◽  
Nikolay E. Polyakov
Keyword(s):  
Glycyrrhizic Acid ◽  
Delivery Systems ◽  
Water Soluble ◽  
Licorice Root ◽  
Acid Media ◽  
Ph Values ◽  
Ancient Times ◽  
Dynamics Simulations ◽  
Dissociated State

Glycyrrhizic acid, or glycyrrhizin (GA), a major active component of licorice root, has been widely used in traditional Chinese and Japanese medicine since ancient times. However, only in the last decades has a novel and unusual property of the GA been discovered to form water-soluble, supramolecular complexes with a variety of lipophilic drugs. These complexes show significant advantages over other known delivery systems, in particular, due to strong pH sensitivity, the properties of GA self-associates. In the present study, a supramolecular complex formation of the hypotensive and antiarrhythmic drug nifedipine with GA has been studied at different pH values, corresponding to the different degrees of GA dissociation, including a fully dissociated state of GA. Both NMR experiments and molecular dynamics simulations demonstrate the existence of the nifedipine complex with GA at all dissociation states of GA. However, optical absorption experiments show the decrease of complex stability and solubility at pH > 6 when the GA molecule is fully deprotonated. It means the higher release rate of the drug in a neutral and basic environment compared with acid media. These results could form the basis of follow-up studies of GA self-associates as pH-controlled drug delivery systems.

Molecular Dynamics Simulations of Glycyrrhizic Acid Aggregates as Drug-Carriers for Paclitaxel

2019 ◽  
Vol 16 (7) ◽  
pp. 618-627 ◽  
Author(s):  
Mumtaz Hussain
Keyword(s):  
Molecular Dynamics ◽  
Glycyrrhizic Acid ◽  
Oral Absorption ◽  
Drug Carrier ◽  
Drug Carriers ◽  
Water Soluble ◽  
Aggregation Behavior ◽  
Dynamics Simulation ◽  
Aqueous Environment ◽  
Dynamics Simulations

Background: Glycyrrhizic acid (GA) is a glycoside that has shown considerable promise as a penetration enhancer and drug carrier to improve the absorption of poorly water-soluble drugs. The aggregation behavior of GA and its ability to form large micelles at higher solution concentrations are thought to contribute to these bioavailability enhancing properties. The oral absorption of Paclitaxel (PTX) for example, an anti-cancer agent which exhibits poor oral bioavailability, has been found to significantly increase in the presence of GA. Methods: In an attempt to visualize the aggregation behavior of GA and its subsequent association with PTX, 100 ns molecular dynamics simulation of a 5 mM aqueous solution of GA with 10 molecules of PTX was conducted using GROMACS and an all-atom forcefield. Results: Aggregation of GA molecules was found to occur quickly at this level of saturation leading to two stable aggregates of 13 and 17 GA molecules with an effective radius of 10.17 nm to 10.92 nm. These aggregates form not in isolation, but together with PTX molecule embedded within the structures, which reduces the number of interactions and hydrogen-bonding with water. Conclusion: GA aggregation occurs around PTX molecules in solution, forming co-joined GA-PTX cluster units at a ratio of 3:1. These clusters remain stable for the remainder of the 100ns simulation and serve to isolate and protect PTX from the aqueous environment.

Lukrecja – czy tylko słodka? Badania kliniczne, bezpieczeństwo stosowania, preparaty

2020 ◽  
Vol 21 (4) ◽  
Author(s):  
Katarzyna Antoniak ◽  
Marlena Dudek-Makuch ◽  
Wiesława Bylka
Keyword(s):  
Clinical Trials ◽  
Essential Oil ◽  
Infectious Diseases ◽  
Respiratory Tract ◽  
Small Groups ◽  
Sweet Taste ◽  
Biological Properties ◽  
Licorice Root ◽  
Ancient Times ◽  
Gastrointestinal Ulceration

Licorice has been used in medicine for ancient times. Licorice root contains active compounds with different activities: saponins, flavonoids, coumarins and essential oil. It shows diverse biological properties. This article presents current achievements with clinical trials and creates new possibilities to use licorice in therapy. It has been proved effectiveness of licorice preparations in infectious diseases of respiratory tract, aphthous stomatitis, in dermatoses and also in skin care. The conducted researches on licorice preparations, especially DGL, present on the pharmaceutical market, which are recommended in gastrointestinal ulceration, have not proved their anti-ulcerative effect. The results of some clinical trials may, however, raise doubts due to the small groups and sometimes the lack of randomization or standardization of the studied preparation. Due to its sweet taste, it is used as a corrigens.

A STUDY OF A WATER-SOLUBLE COMPLEX OF PRODIGIOSIN PRODUCED BY A STRAIN OF SERRATIA MARCESCENS

1962 ◽  
Vol 40 (1) ◽  
pp. 1019-1024 ◽  
Author(s):  
Seiichi Yoshida
Keyword(s):  
Molecular Weight ◽  
Light Scattering ◽  
Serratia Marcescens ◽  
Average Molecular Weight ◽  
Electrophoretic Analysis ◽  
Water Soluble ◽  
Soluble Complex ◽  
Ph Values ◽  
Scattering Measurements ◽  
Water Soluble Complex

A water-soluble pigment excreted from Serratia marcescens has been purified by precipitation with ammonium sulphate, dialysis, and ultracentrifugation at different pH values. The purified pigment showed a single band in the ultracentrifuge and by electrophoretic analysis at several pH values. An average molecular weight of 5 × 106 was calculated from light-scattering measurements. This pigment is composed of carbohydrate and protein combined with prodigiosin, and several properties of the complex are described.

scholarly journals A Very Rare Cause of Dilated Cardiomyopathy after Bariatric Surgery: Selenium Deficiency

2021 ◽  
pp. 1-3
Author(s):  
Gulay Kocak ◽  
Munevver Gul Avsar ◽  
Cansu Yazar ◽  
Aylia Yesilova ◽  
Gulcagri Yildiz ◽  
...  
Keyword(s):  
Bariatric Surgery ◽  
Trace Elements ◽  
Sleeve Gastrectomy ◽  
Dilated Cardiomyopathy ◽  
Selenium Deficiency ◽  
Water Soluble ◽  
Nutritional Deficiencies ◽  
Reduced Ejection Fraction ◽  
Long Term Follow Up

Background: Sleeve gastrectomy for weight loss has increased significantly nowadays. Various complications may develop after this surgery that requires long-term follow-up of these patients. Nutrition is the most important aspect of the follow-up. The deficiency of trace elements, fat-soluble and water-soluble vitamins following bariatric surgeries have been well-described complications. Although nutritional supplementations are often initiated after bariatric surgery, the clinical outcomes related to the deficiency of trace elements have not been well known yet. Case Presentation: A 27-year-old woman who underwent a laparoscopic sleeve gastrectomy for surgical treatment of obesity 9 months ago presented to the emergency department with a signs of heart failure. Transthoracic echocardiography revealed dilated, poorly functioning left ventricle with reduced ejection fraction (28.9%) consistent with dilated cardiomyopathy. We assumed nutritional deficiencies secondary to sleeve gastrectomy as a cause of dilated cardiomyopathy, as the patient had inappropriate nutritional supplements after surgery. Laboratory tests revealed selenium and zinc deficiency that supported our hypothesis. Our patient completely recovered with adequate supplementation of selenium, zinc and thiamine. Conclusion: We highlighted that the early diagnosis of dilated cardiomyopathy due to selenium deficiency following bariatric surgery is of great importance since selenium deficiency is a cause of reversible cardiomyopathy.

scholarly journals Approaches to improve the growth of the starter lactic acid bacterium OM13 during the early stages of green Spanish-style table olive production

2018 ◽  
Vol 69 (3) ◽  
pp. 265
Author(s):  
A. Alfonzo ◽  
A. Martorana ◽  
L. Settanni ◽  
M. Matraxia ◽  
O. Corona ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Starter Culture ◽  
Table Olives ◽  
Acid Fermentation ◽  
Lactobacillus Pentosus ◽  
Ph Values ◽  
Organoleptic Characteristics ◽  
Fermented Product ◽  
And Control

The present research aimed at determining the optimal conditions for the lactic acid fermentation of green Spanish-style table olives. The work is a follow-up, and focuses on the performance of the commercial starter strain Lactobacillus pentosus OM13 by applying an acclimatization step and the addition of nutrients, and concentrations of lactic acid that were previously investigated. The acclimatization of the cells warranted the dominance of the starter culture even at an inoculation level of 2 Log cycles lower than that commonly used in standard fermentation. A significant effect was found in terms of acidification kinetics within the first week of fermentation, with the highest decrease in pH, at ~2.5 units, which occurred in the trial and after inoculation with 106 CFU/mL of starter after acclimatation (EO3) that showed values similar to control C obtained with Lactobacillus pentosus OM13 at a concentration of 107 CFU/mL. After day 3, further decreases in pH of up to 4.30 were observed until day 30, and then these values remained almost constant until the end of process (day 190) when lower pH values were reached for trial EO3 and control C. The results of microbiological dynamics, the changes in VOCs and finally the effect of the processes on the sensory analysis of the fermented product were investigated by multivariate analysis. The acclimatization process and the initial inoculation level influenced the bacterial microflora, aromatic compounds and organoleptic characteristics of the final product. Finally, the trials C, EO2 and EO3 showed higher values (60-80%) of preferences and satisfaction compared to other experimental productions.

scholarly journals Membranes serve as allosteric activators of phospholipase A2, enabling it to extract, bind, and hydrolyze phospholipid substrates

2015 ◽  
Vol 112 (6) ◽  
pp. E516-E525 ◽  
Author(s):  
Varnavas D. Mouchlis ◽  
Denis Bucher ◽  
J. Andrew McCammon ◽  
Edward A. Dennis
Keyword(s):  
Extraction Process ◽  
Water Soluble ◽  
Mass Spectrometry Data ◽  
Allosteric Site ◽  
Dynamic Simulations ◽  
Lipid Interactions ◽  
Exchange Mass Spectrometry ◽  
Ideal System ◽  
Group Iva ◽  
Dynamics Simulations

Defining the molecular details and consequences of the association of water-soluble proteins with membranes is fundamental to understanding protein–lipid interactions and membrane functioning. Phospholipase A2(PLA2) enzymes, which catalyze the hydrolysis of phospholipid substrates that compose the membrane bilayers, provide the ideal system for studying protein–lipid interactions. Our study focuses on understanding the catalytic cycle of two different human PLA2s: the cytosolic Group IVA cPLA2and calcium-independent Group VIA iPLA2. Computer-aided techniques guided by deuterium exchange mass spectrometry data, were used to create structural complexes of each enzyme with a single phospholipid substrate molecule, whereas the substrate extraction process was studied using steered molecular dynamics simulations. Molecular dynamic simulations of the enzyme–substrate–membrane systems revealed important information about the mechanisms by which these enzymes associate with the membrane and then extract and bind their phospholipid substrate. Our data support the hypothesis that the membrane acts as an allosteric ligand that binds at the allosteric site of the enzyme’s interfacial surface, shifting its conformation from a closed (inactive) state in water to an open (active) state at the membrane interface.

scholarly journals Low molecular mass chitosan as carrier for a hydrodynamically balanced system for sustained delivery of ciprofloxacin hydrochloride

2012 ◽  
Vol 62 (2) ◽  
pp. 237-250 ◽  
Author(s):  
Anurag Verma ◽  
Ashok Bansal ◽  
Amitava Ghosh ◽  
Jayanta Pandit
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Molecular Mass ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Water Soluble ◽  
Sustained Delivery ◽  
Ciprofloxacin Hydrochloride ◽  
Water Soluble Drug ◽  
Major Interest

Low molecular mass chitosan as carrier for a hydrodynamically balanced system for sustained delivery of ciprofloxacin hydrochloride Chitosan has become a focus of major interest in recent years due to its excellent biocompatibility, biodegradability and non-toxicity. Although this material has already been extensively investigated in the design of different types of drug delivery systems, it is still little explored for stomach specific drug delivery systems. The objective of the present investigation was to explore the potential of low molecular mass chitosan (LMCH) as carrier for a hydrodynamically balanced system (HBS) for sustained delivery of water soluble drug ciprofloxacin hydrochloride (CP). Various formulations were prepared by physical blending of drug and polymer(s) in varying ratios followed by encapsulation into hard gelatin capsules. All the formulations remained buoyant in 0.1 mol L-1 HCl (pH 1.2) throughout the experiment. Effect of addition of xanthan gum (XG) or ethyl cellulose (EC) on drug release was also investigated. Zero order drug release was obtained from the formulations containing LMCH alone or in combination with XG, and in one instance also with EC. Our results suggest that LMCH alone or in combination with XG is an excellent material for stomach specific sustained delivery of CP from hydrodynamically balanced single unit capsules.

Clay-based Formulations for Bioavailability Enhancement of Poorly Water-soluble Drugs

2021 ◽  
Vol 22 ◽  
Author(s):  
Phuong H.L. Tran ◽  
Thao T.D. Tran
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Delivery Systems ◽  
Water Soluble ◽  
Limited Information ◽  
Bioavailability Enhancement ◽  
Poorly Water Soluble Drugs ◽  
Ideal System ◽  
Water Soluble Drugs ◽  
Poorly Water Soluble

: Clays have been used in various health care products, including drug delivery systems. Advanced formulations have been investigated to take full advantage of clays or clay-based materials. The remarkable properties of clays, such as high adsorption, high surface area, and high ion exchange capacities, provide an ideal system for the delivery of poorly water-soluble drugs. There is currently limited information on the classification and discussion of clay-based formulations for poorly water-soluble drugs. This review aims to describe efficient delivery systems that use clay as the main excipient in formulations. More details about the strategies of using clays in formulations as well as fabrication methods will be discussed. Moreover, combinations with other excipients in hybrid formulations will also be mentioned in evaluating the efficacy of these systems. The highlighted recent studies on clay-based formulations for poorly water-soluble drugs could provide fundamental approaches and prospects to apply them in drug development.

Innovative Strategies for Lipid-Based Drug Delivery

2018 ◽  
pp. 60-84 ◽  
Author(s):  
Navneet Sharma ◽  
Sabna Kotta ◽  
Mohd Aleem ◽  
Shubham Singh ◽  
Rakesh Kumar Sharma
Keyword(s):  
Drug Delivery ◽  
Drug Absorption ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Water Soluble ◽  
Absorption Process ◽  
Innovative Strategies ◽  
The Poor ◽  
Water Soluble Drugs ◽  
Selection Of

In the last decade, there has been a mounting concern in lipid-based formulations to deliver water-soluble drugs. Lipid-based drug delivery systems are one of the budding and promising technologies designed to tackle the poor bioavailability problems. This chapter stresses the different mechanisms of lipophilic drug absorption along with its advantages and limitations. It points out the different mechanisms of how lipid-based excipients and the different formulations interact with the absorption process. This review provides a comprehensive summary about the lipid formulation classification scheme (LFCS), a guide for the selection of appropriate formulation and commonly used excipients for lipid-based formulations, along with the important factors to be considered in formulation design and excipient selection. This review also focuses on the formulation of solid lipid-based formulations, important evaluation aspects, and commercial formulations available for the purpose.

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