scholarly journals Stability study of tubular DNA origami in the presence of protein crystallisation buffer

RSC Advances ◽  
2015 ◽  
Vol 5 (72) ◽  
pp. 58734-58737 ◽  
Author(s):  
Dianming Wang ◽  
Ziran Da ◽  
Bohan Zhang ◽  
Mark Antonin Isbell ◽  
Yuanchen Dong ◽  
...  
Keyword(s):  
Stability Study ◽  
Dna Origami ◽  
The Stability

A method for screening compatible buffer conditions for both DNA origami and protein crystallisation and studied how protein crystallisation buffer conditions notably cations, buffering agents, precipitants, and pH, influenced the stability of tubular DNA origami.

scholarly journals Limitations and Challenges in the Stability of Cysteamine Eye Drop Compounded Formulations

2021 ◽  
Vol 15 (1) ◽  
pp. 2
Author(s):  
Cristina Martín-Sabroso ◽  
Mario Alonso-González ◽  
Ana Fernández-Carballido ◽  
Juan Aparicio-Blanco ◽  
Damián Córdoba-Díaz ◽  
...  
Keyword(s):  
Shelf Life ◽  
Stability Study ◽  
Eye Drops ◽  
Microbiological Analysis ◽  
Nitrogen Gas ◽  
Long Term Stability ◽  
Main Degradation Product ◽  
The Stability ◽  
Unstable Molecule

Accumulation of cystine crystals in the cornea of patients suffering from cystinosis is considered pathognomonic and can lead to severe ocular complications. Cysteamine eye drop compounded formulations, commonly prepared by hospital pharmacy services, are meant to diminish the build-up of corneal cystine crystals. The objective of this work was to analyze whether the shelf life proposed for six formulations prepared following different protocols used in hospital pharmacies is adequate to guarantee the quality and efficacy of cysteamine eye drops. The long-term and in-use stabilities of these preparations were studied using different parameters: content of cysteamine and its main degradation product cystamine; appearance, color and odor; pH and viscosity; and microbiological analysis. The results obtained show that degradation of cysteamine was between 20% and 50% after one month of storage in the long-term stability study and between 35% and 60% in the in-use study. These data confirm that cysteamine is a very unstable molecule in aqueous solution, the presence of oxygen being the main degradation factor. Saturation with nitrogen gas of the solutions offers a means of reducing cysteamine degradation. Overall, all the formulae studied presented high instability at the end of their shelf life, suggesting that their clinical efficacy might be dramatically compromised.

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 The stability study of a plane engine

2000 ◽  
Vol 27 (1) ◽  
pp. 35-44
Author(s):  
Rafał Kołodziej ◽  
Tomasz Nowicki
Keyword(s):  
Stability Study ◽  
The Stability

scholarly journals Physicochemical Properties and Stability of Microencapsulated Betacyanin Pigments from Red Dragon Fruit Peels and Flesh

2020 ◽  
pp. 141-148
Author(s):  
Rosalinda C Torres ◽  
Rowelain Mae G Yumang ◽  
Chelsea Kate F Jose ◽  
Danielle Camille P Canillo
Keyword(s):  
Moisture Content ◽  
Physicochemical Properties ◽  
Morphological Characterization ◽  
Stability Study ◽  
Natural Colorant ◽  
Hygroscopic Moisture ◽  
Dragon Fruit ◽  
The Stability ◽  
Spray Dried ◽  
Hylocereus Polyrhizus

Dragon fruit (Hylocereus polyrhizus) is known for its purple-coloured peels and pulp, which can be attributed to the presence of betalains. In this study, the potential of red dragon fruit as a source of natural colorant was investigated. Betacyanins were extracted from red dragon fruit peels and flesh in 1:3 ratio with water. Microencapsulation by spray-drying was done by adding 5% and 10% (w/v) maltodextrin (DE 11.8) to peels and flesh extracts, respectively. The spray-dried colorant powders all obtained <10% moisture content, 5.261-6.409 g/100g hygroscopic moisture content, and 5.317-7.349(mg/100L) betacyanin content. Morphological characterization revealed spherical, agglomerated particles with visible cracks on the surface. The stability study conducted showed that pigment retention was lowest at 70°C and highest at 4°C. Keywords: Hylocereus polyrhizus; Red dragon fruit; Betacyanin; Microencapsulation; Physicochemical properties

scholarly journals A Fast and Validated HPLC Method for Simultaneous Determination of Dopamine, Dobutamine, Phentolamine, Furosemide, and Aminophylline in Infusion Samples and Injection Formulations

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Fuchao Chen ◽  
Baoxia Fang ◽  
Sicen Wang
Keyword(s):  
Mobile Phase ◽  
Dosage Form ◽  
Limit Of Detection ◽  
Hplc Method ◽  
Stability Study ◽  
Precision Data ◽  
Column Temperature ◽  
Ich Guidelines ◽  
Limit Of Quantitation ◽  
The Stability

A simple, fast, and validated HPLC method was developed for the simultaneous quantization of five cardiovascular agents: dopamine (DPM), dobutamine (DBM), phentolamine (PTM), furosemide (FSM), and aminophylline (APL) either in infusion samples or in an injection dosage form. The proposed method was achieved with a 150 mm × 4.6 mm, 5.0 μm C18 column, by using a simple linear gradient. Mobile phase A was buffer (50 mM KH2PO4) and mobile Phase B was acetonitrile at a flow rate of 1.0 mL/min. The column temperature was kept at 30°C, and the injection volume was 20 μL. All analytes were separated simultaneously at a retention time (tr) of 3.93, 5.84, 7.06, 8.76, and 9.67 min for DPM, DBM, PTM, FSM, and APL, respectively, with a total run time of less than 15.0 min. The proposed method was validated according to ICH guidelines with respect to accuracy, precision, linearity, limit of detection, limit of quantitation, and robustness. Linearity was obtained over a concentration range of 12.0–240.0, 12.0–240.0, 20.0–200.0, 6.0–240.0, and 10.0–200.0 μg/mL DPM, DBM, PTM, FSM, and APL, respectively. Interday and intraday accuracy and precision data were recorded in the acceptable limits. The new method has successfully been applied for quantification of all five drugs in their injection dosage form, infusion samples, and for evaluation of the stability of investigated drugs in mixtures for endovenous use. The results of the stability study showed that mixtures of DPM, DBM, PTM, FSM, and APL in 5% glucose or 0.9% sodium chloride injection were stable for 48 hours when stored in polypropylene syringes at 25°C.

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.

scholarly journals Preservatives Stability: Stability Study of Parabens under Different Conditions of Stress Degradation

2020 ◽  
Vol 11 (3) ◽  
pp. 4187-4194
Author(s):  
Ismail Bennani ◽  
Madiha Alami Chentoufi ◽  
Miloud El Karbane ◽  
Ibrahim Sbai El Otmani ◽  
Amine Cheikh ◽  
...  
Keyword(s):  
Extreme Values ◽  
Stability Study ◽  
Wide Field ◽  
Direct Influence ◽  
Light Conditions ◽  
Influence Of Temperature ◽  
Stress Degradation ◽  
Quality Of Products ◽  
The Stability

Preservatives are used in a wide field of application to maintain the quality of products. They are used to deal with the chemical, physical and microbiological problems and the constraints of the development of several formulations. In this work, we tested the stability of antimicrobial preservatives which are the parabens under different stress degradation conditions to evaluate their degree of effectiveness. The tested parabens were incubated in different solutions at different pH, Temperatures, light conditions, and presence or absence of sucrose in solution (create a medium similar of syrups). The HPLC was used for the assay, by a validated method for the parabens assay and the statistical analysis of the data is carried out by JMP software. The results show a direct influence of temperature and pH on the level of parabens, while the influence of light remains negligible. The increase in temperature gives a degree of immunity of parabens levels, especially with the extreme values of pH. This study is one of the first studies of forced decomposition of parabens carried out under the various conditions suggested. The results give an idea of the stability profile of the tested parabens and suggest a model of the conditions of conservation and use of these products in different domains and under different conditions.

scholarly journals STABILITY STUDY OF AMLODIPINE BESYLATE AND BISOPROLOL FUMARATE IN AQUEOUS SOLUTIONS

2014 ◽  
Vol 5 (2) ◽  
Author(s):  
Irena Kasagić Vujanović ◽  
Dijana Jelić ◽  
Vesna Antunović ◽  
Biljana Jančić Stojanović ◽  
Darko Ivanović
Keyword(s):  
Relevant Information ◽  
Pharmaceutical Product ◽  
Stability Study ◽  
Amlodipine Besylate ◽  
Time Intervals ◽  
Constant Rate ◽  
Different Temperatures ◽  
The Media ◽  
Two Temperatures ◽  
The Stability

Valuable information concerning stability of compounds can be obtained by using different media (water, hydrochloric acid or sodium hydroxide) for dissolution of active pharmaceutical substances. Furthermore, additional knowledge is gained by performing experiments at different temperatures. This research paper deals with the stability of amlodipine besylate and bisoprolol fumarate in different media at different temperatures, whereby certain conclusions are drawn. For stability assessment, chemical kinetics approach was used, and constant rate (k), half-time (t1/2) and activation energy (Ea) were used for prediction of compound stability degree. The stability of amlodipine besylate and bisoprolol fumarate were tested, both separately and in mixture, in water and in 0.01M HCl. All the investigated solutions were treated at two temperatures 25° and 70°C at the following time intervals: 0, 1 h, 24 h, 48 h and 72 h. Hydrophilic Interaction Liquid Chromatography – HILIC method, previously developed and validated, was used. On the basis of obtained results it was concluded that amlodipine-besylate was more stable in water than in acid medium, more stable in mixture rather than individually and more stable at lower temperatures. This was confirmed by the obtained values of monitored parameters: amlodipine besylate Ea = 30.68 kJ mol-1, k (25 °C) = 0.000333 mM h-1, k (70 °C) = 0.00169 mM h-1; amlodipine besylate in mixture Ea = 42,414 kJ mol-1, k (25 °C) = 1.27∙10-4 mM h-1, k (70 °C) = 0.0012 mM h-1. Based on the obtained approximate Ea value for bisoprolol fumarate in acid (59 kJ mol-1) and in water (56 kJ mol-1), bisoprolol fumarate showed excellent stability against the media in which it was studied. On the other hand, the temperature had a significant effect on the stability of bisoprolol fumarate. These results provide the relevant information about the stability of the tested active substances, and may be of importance during the development of an appropriate pharmaceutical product. A bigger influence on the stability of bisoprolol fumarate had a temperature effect.

scholarly journals STANDARDIZATION AND STABILITY EVALUATION OF DRY EXTRACTS OF MYRACRODRUON URUNDEUVA ALLEMÃO OBTAINED BY SPRAY DRIER

2017 ◽  
Vol 9 (2) ◽  
pp. 154 ◽  
Author(s):  
Renata Da Silva Leite ◽  
Valmir Gomes De Souza ◽  
Agna HÉlia De Oliveira ◽  
JosÉ VenÂncio Chaves JÚnior ◽  
Islaine De Souza Salvador ◽  
...  
Keyword(s):  
Silicon Dioxide ◽  
Feed Rate ◽  
Stability Study ◽  
Inflammatory Activity ◽  
Inlet Temperature ◽  
Dry Extract ◽  
Anti Inflammatory ◽  
The Stability ◽  
Drying Conditions ◽  
Quercetin Concentration

<p><strong>Objective</strong>:<strong> </strong>This study aimed to obtain standardised dry extracts of <em>Miracrodruon urundeuva </em>Allemão using spray-dryer and evaluate the stability of the extracts.</p><p><strong>Methods</strong>:<strong> </strong>It evaluated the drying parameters: Proportion of colloidal silicon dioxide (CSD) (10, 15 and 20%), inlet temperature (160, 170 and 180 °C) and feed rate (4, 6 and 8 ml/min). The study of the accelerated stability of dry extract occurred in temperature of 40 °C (±2 °C) and relative humidity of 75% (±5%) for 6 mo. The anti-inflammatory activity of the dry extract was evaluated in Swiss mice by the paw edema method.</p><p><strong>Results</strong>:<strong> </strong>Variations in drying conditions did not represent significant variations in yields of the process. The drying temperature and feed rate significantly influenced the concentration of quercetin (p≤0.05). The increase in inlet temperature and feed flow promoted the increase of quercetin concentration in the extracts. The stability study showed that the concentration of quercetin in dry extract was stable over a period of 6 mo. The dry extract showed anti-inflammatory activity in mice orally.</p><p><strong>Conclusion</strong>:<strong> </strong>A condition of 10% of colloidal silicon dioxide with an 180 °C inlet temperature and a feed rate of 8 ml/min was considered the most adequate for obtaining the extracts and the drying process resulted in stable dry extracts and the quercetin was a suitable biomarker for monitoring the process.</p>

Sign in / Sign up

Export Citation Format

Share Document