scholarly journals Ru(III) Complexes with Lonidamine-Modified Ligands

2021 ◽  
Vol 22 (24) ◽  
pp. 13468
Author(s):  
Ilya A. Shutkov ◽  
Yulia N. Okulova ◽  
Vladimir Yu. Tyurin ◽  
Elena V. Sokolova ◽  
Denis A. Babkov ◽  
...  
Keyword(s):  
Water Solubility ◽  
Aerobic Glycolysis ◽  
Thioredoxin Reductase ◽  
Selective Inhibitor ◽  
Apoptosis Induction ◽  
Stability Studies ◽  
New Agents ◽  
Stability Of Complexes ◽  
The Stability ◽  
New Compounds

A series of bifunctional Ru(III) complexes with lonidamine-modified ligands (lonidamine is a selective inhibitor of aerobic glycolysis in cancer cells) was described. Redox properties of Ru(III) complexes were characterized by cyclic voltammetry. An easy reduction suggested a perspective for these agents as their whole mechanism of action seems to be based on activation by metal atom reduction. New compounds demonstrated a more pronounced antiproliferative potency than the parental drug; individual new agents were more cytotoxic than cisplatin. Stability studies showed an increase in the stability of complexes along with the linker length. A similar trend was noted for antiproliferative activity, cellular uptake, apoptosis induction, and thioredoxin reductase inhibition. Finally, at concentrations that did not alter water solubility, the selected new complex evoked no acute toxicity in Balb/c mice.

scholarly journals Characterization and Stability Evaluation of Thymoquinone Nanoemulsions Prepared by High-Pressure Homogenization

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Zaki Tubesha ◽  
Zuki Abu Bakar ◽  
Maznah Ismail
Keyword(s):  
High Pressure ◽  
Water Solubility ◽  
Particle Sizes ◽  
High Pressure Homogenization ◽  
Stability Evaluation ◽  
Stability Studies ◽  
Initial Particle ◽  
Oil In Water ◽  
The Stability

Despite the pharmacological properties of thymoquinone (TQ), its administrationin vivoremains problematic partly due to its poor water solubility, leading to low absorptivity and bioavailability. Hence, the objective of this study is to prepare, characterize, and evaluate the stability of TQ nanoemulsion (TQNE). Conventional emulsion from TQ (TQCE) and empty nano- and conventional emulsions from Triolein (TRNE and TRCE) are also produced for comparison purposes. The oil-in-water nanoemulsions of TQ and Triolein were produced by high-pressure homogenization. Emulsions were characterized physically by droplet size, polydispersity index, zeta potential, and refractive index. The changes of these parameters in TQNE samples stored for 6 months at 4 and 25°C were not statistically significant (P<0.05). In addition, the initial particle sizes of TQNE and TRNE were 119.6 and 119.5 nm, respectively. Stability studies were also performed for the period of 6 months. At the end of the experiment, the percent of remaining TQ in TQNE at 4, 25, and 40°C was 90.6, 89.1, and 87.4 % respectively. Slower degradation of TQ indicated the chemical stability of TQ in TQNE samples. These results indicated that TQNE is stable over a period of 6 months.

scholarly journals Direct Amidation to Access 3-Amido-1,8-Naphthalimides Including Fluorescent Scriptaid Analogues as HDAC Inhibitors

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1505
Author(s):  
Kyle N. Hearn ◽  
Trent D. Ashton ◽  
Rameshwor Acharya ◽  
Zikai Feng ◽  
Nuri Gueven ◽  
...  
Keyword(s):  
Optical Properties ◽  
Histone Deacetylase ◽  
Good Yield ◽  
Hdac Inhibitors ◽  
Selective Inhibitor ◽  
Imaging Studies ◽  
Highly Active ◽  
Theranostic Applications ◽  
New Compounds ◽  
Direct Amidation

Methodology to access fluorescent 3-amido-1,8-naphthalimides using direct Buchwald–Hartwig amidation is described. The protocol was successfully used to couple a number of substrates (including an alkylamide, an arylamide, a lactam and a carbamate) to 3-bromo-1,8-naphthalimide in good yield. To further exemplify the approach, a set of scriptaid analogues with amide substituents at the 3-position were prepared. The new compounds were more potent than scriptaid at a number of histone deacetylase (HDAC) isoforms including HDAC6. Activity was further confirmed in a whole cell tubulin deacetylation assay where the inhibitors were more active than the established HDAC6 selective inhibitor Tubastatin. The optical properties of these new, highly active, compounds make them amenable to cellular imaging studies and theranostic applications.

scholarly journals Recent Findings in Azaphilone Pigments

2021 ◽  
Vol 7 (7) ◽  
pp. 541
Author(s):  
Lúcia P. S. Pimenta ◽  
Dhionne C. Gomes ◽  
Patrícia G. Cardoso ◽  
Jacqueline A. Takahashi
Keyword(s):  
Water Solubility ◽  
Biological Activities ◽  
Low Cost ◽  
Scale Up ◽  
Structural Diversity ◽  
Downstream Processing ◽  
Global Market ◽  
Yield Improvement ◽  
Potential Applications ◽  
New Compounds

Filamentous fungi are known to biosynthesize an extraordinary range of azaphilones pigments with structural diversity and advantages over vegetal-derived colored natural products such agile and simple cultivation in the lab, acceptance of low-cost substrates, speed yield improvement, and ease of downstream processing. Modern genetic engineering allows industrial production, providing pigments with higher thermostability, water-solubility, and promising bioactivities combined with ecological functions. This review, covering the literature from 2020 onwards, focuses on the state-of-the-art of azaphilone dyes, the global market scenario, new compounds isolated in the period with respective biological activities, and biosynthetic pathways. Furthermore, we discussed the innovations of azaphilone cultivation and extraction techniques, as well as in yield improvement and scale-up. Potential applications in the food, cosmetic, pharmaceutical, and textile industries were also explored.

scholarly journals Stability Studies of Transition Metal Chelates of 5-Bromosalicylidene-4-methoxyaniline andSalicylidene-2,3-dimethylaniline as Ligands

2011 ◽  
Vol 8 (4) ◽  
pp. 1911-1915
Author(s):  
N. G. Nadkarni ◽  
K. V. Mangaonkar
Keyword(s):  
Ionic Strength ◽  
Transition Metal ◽  
Stability Constants ◽  
Metal Chelates ◽  
Ternary Complexes ◽  
Water Medium ◽  
Stability Studies ◽  
Binary And Ternary Complexes ◽  
Transition Metal Chelates ◽  
The Stability

Binary and ternary complexes of the type M-Y and M-X-Y [M = Mn(II), Ni(II), Cu(II) and Zn(II); X = 5-bromosalicylidene-4-methoxyaniline and Y = salicylidene-2,3-dimethylaniline] have been examined pH-metrically at 27±0.5°C and at constant ionic strength, μ = 0.1 M (KCl) in 75 : 25(v/v) 1,4-dioxne-water medium. The stability constants for binary (M-Y) and ternary (M-X-Y) systems were calculated.

Stability of extemporaneously prepared rosuvastatin oral suspension

2017 ◽  
Vol 74 (19) ◽  
pp. 1579-1583 ◽  
Author(s):  
Abdel Naser Zaid ◽  
Rania Shtayah ◽  
Ayman Qadumi ◽  
Mashour Ghanem ◽  
Rawan Qedan ◽  
...  
Keyword(s):  
Relative Humidity ◽  
High Performance ◽  
Room Temperature ◽  
Microbial Contamination ◽  
Active Pharmaceutical Ingredient ◽  
Storage Conditions ◽  
Dissolution Profile ◽  
Stability Studies ◽  
Organoleptic Properties ◽  
The Stability

Abstract Purpose The stability of an extemporaneously prepared rosuvastatin suspension stored over 30 days under various storage conditions was evaluated. Methods Rosuvastatin suspension was extemporaneously prepared using commercial rosuvastatin tablets as the source of active pharmaceutical ingredient. The organoleptic properties, dissolution profile, and stability of the formulation were investigated. For the stability studies, samples of the suspension were stored under 2 storage conditions, room temperature (25 °C and 60% relative humidity) and accelerated stability chambers (40 °C and 75% relative humidity). Viscosity, pH, organoleptic properties, and microbial contamination were evaluated according to the approved specifications. High-performance liquid chromatography was used for the analysis and quantification of rosuvastatin in selected samples. Microbiological investigations were also conducted. Results The prepared suspension showed acceptable organoleptic properties. It showed complete release of rosuvastatin within 15 minutes. The pH of the suspension was 9.8, which remained unchanged during the stability studies. The microbiological investigations demonstrated that the preparation was free of any microbial contamination. In addition, the suspension showed stability within at least the period of use of a 100-mL rosuvastatin bottle. Conclusion Extemporaneously prepared rosuvastatin 20-mg/mL suspension was stable for 30 days when stored at room temperature.

scholarly journals FORMULATION, CHARACTERIZATION AND STABILITY STUDY OF FAST DISSOLVING THIN FILM CONTAINING ASTAXANTHIN NANOEMULSION USING HYDROXYPROPYLMETHYL CELLULOSE POLYMER

2021 ◽  
pp. 17-22
Author(s):  
LUSI NURDIANTI ◽  
IYAN SOPYAN ◽  
TAOFIK RUSDIANA
Keyword(s):  
Thin Film ◽  
Mechanical Characteristics ◽  
Storage Conditions ◽  
Stability Study ◽  
Matrix System ◽  
Stability Studies ◽  
Casting Method ◽  
Hydroxypropylmethyl Cellulose ◽  
The Stability ◽  
Physical And Mechanical Characteristics

Objective: The present study was conducted to formulate and characterize the thin film containing astaxanthin nanoemulsion (TF-ASN) using Hydroxypropylmethyl Cellulose (HPMC) polymer as a film matrix system. The stability studies in different storage conditions were also performed. Methods: Astaxanthin nanoemulsion (As-NE) was prepared by using self-nanoemulsifying method, followed by incorporation into the HPMC matrix system by solvent casting method to forming TF-ASN. Evaluation of TF-ASN was performed by physical and mechanical characterizations. Stability study was carried out in both of accelerated (temperature of 40±2 °C/75±5% RH) and non-accelerated (at ambient temperature) conditions. Assay of astaxanthin in individual TF-ASN was determined compared to pure astaxanthin. Results: TF-ASN had good physical and mechanical characteristics that suitable for intraoral administration. Conclusion: For the study of stability under different storage conditions, it was proven that nanoemulsion form was packed in a HPMC matrix could enhance the stability of the astaxanthin.

scholarly journals Encapsulation Systems for Delivery of Flavonoids: A Review

2021 ◽  
Vol 11 (6) ◽  
pp. 13934-13951
Keyword(s):  
Fruits And Vegetables ◽  
Water Solubility ◽  
Biological Activities ◽  
Molecular Complexes ◽  
Multilamellar Vesicles ◽  
Promising Tool ◽  
Inflammatory Bowel ◽  
The Stability ◽  
Encapsulation Methods ◽  
As Solubility

Encapsulation of bioactive compounds s been considered a promising tool for preserving these compounds. Several studies on dietary sources and health benefits of flavonoids, their chemical and stability properties, and encapsulation methods used for delivery of flavonoids were reviewed. Flavonoids comprise the main group of polyphenols widely found in fruits and vegetables responsible for numerous biological activities. They have a flavan nucleus with 15 carbon atoms organized in three rings and are categorized into six subgroups. The main dietary sources of flavonoids are fruits, vegetables, cereals, tea, and some herbs such as Viola odorata Linn. These compounds can prevent diseases such as cardiovascular, cancers, neurodegenerative, diabetes, and inflammatory bowel disease. Despite these beneficial biological activities, flavonoids are not stable against environmental conditions, have low water solubility and low bioavailability after oral administration, which restricts their application. Accordingly, encapsulation has been utilized in order to improve the stability and solubility of flavonoids. Various approaches such as spray drying, molecular complexes, liposomes, nanoparticles, emulsification, and multilamellar vesicles have been applied in the entrapment of flavonoids. Encapsulation can improve the stability of flavonoids as well as solubility, controlled release, and bioavailability.

scholarly journals Stability study of rock slope in fractured quartzite at right side of spillway, Middle Marsyangdi Hydroelectric Project, Nepal

2003 ◽  
Vol 28 ◽  
Author(s):  
Kaustubh Mani Nepal ◽  
Roger Olsson
Keyword(s):  
Rock Slope ◽  
Stability Study ◽  
Cut Slope ◽  
Stability Studies ◽  
Hydroelectric Project ◽  
The Stability ◽  
The Right ◽  
Cut Slopes

A 120 m long and 68 m high rock cut slope is designed at the right side of spillway of Middle Marsyangdi Hydroelectric Project. This paper describes the stability studies performed for the rock cut slopes in jointed quartzite for foundation of spillway.

Assembly of discrete and oligomeric structures of organotin double-decker silsesquioxanes: inherent stability studies

2021 ◽  
Author(s):  
Pushparaj Loganathan ◽  
Renjith S. Pillai ◽  
Velusamy Jeevananthan ◽  
Ezhumalai David ◽  
Nallasamy Palanisami ◽  
...  
Keyword(s):  
Crystal Lattice ◽  
Computational Study ◽  
Stability Studies ◽  
Double Decker ◽  
The Stability ◽  
Inherent Stability

Discrete and oligomeric organotin DDSQs have been synthesized and characterized, both experimentally and through computational study. The stability of these compounds remains intrigued with the organization of their structure in the crystal lattice.

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

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