Flexible Solid PANI Fiber Networks/Ni‐MOF@CC Electrodes for High‐Performance Capacitors: Synthesis and Stability Study

2020 ◽  
Vol 5 (34) ◽  
pp. 10656-10662
Author(s):  
Shibo Dong ◽  
Qiguan Wang ◽  
Wenzhi Zhang ◽  
Jian Chen ◽  
Sumin Wang
Author(s):  
G D Chandrethiya ◽  
P K Shelat ◽  
M N Zaveri

PEGylated gelatin nanoparticles loaded with colchicine were prepared by ethanol precipitation method. Poly-(ethylene glycol)-5000-monomethylether (MPEG 5000), a hydrophilic polymer, was used to pegylate gelatin.  Gluteraldehyde was used as cross-linking agent. To obtain a high quality product, major formulation parameters were optimized.  Spherical particles with mean particles of 193 nm were measured by a Malvern particle size analyzer. Entrapment efficiency was found to be 71.7 ± 1.4% and determined with reverse phase high performance liquid charomatography (RP-HPLC). The in vitro drug release study was performed by dialysis bag method for a period of 168 hours. Lyophilizaton study showed sucrose at lower concentrations proved the best cryoprotectant for this formulation.  Stability study revealed that lyophilized nanoparticles were equally effective (p < 0.05) after one year of storage at 2-8°C with ambient humidity. In vitro antitumoral activity was accessed using the MCF-7 cell line by MTT assay.  The IC50 value was found to be 0.034 μg/ml for the prepared formulation. The results indicate that PEGylated gelatin nanoparticles could be utilized as a potential drug delivery for targeted drug delivery of tumors.  


2021 ◽  
pp. 107815522199120
Author(s):  
Mélanie Hinterlang ◽  
Amandine Gendron ◽  
Thomas Fleury ◽  
André Rieutord ◽  
Anastasia Vrana ◽  
...  

Background Imatinib is a protein-tyrosine kinase inhibitor which is currently only commercially available as a tablet dosage form in the strength of 100mg and 400mg. The elaboration of new oral liquid formulations is suitable in pediatrics and for patients who have difficulties to swallow, notably in the absence of commercial forms. This enables the adaptation of dosage and secure the administration. Objectives The formulation of an oral pediatric solution of imatinib at a concentration of 30 mg/mL and the evaluation of its stability for the treatment of pediatric patients with Philadelphia chromosome positive chronic myeloid leukemia. Methods The physicochemical stability parameters: appearance, pH, osmolality, and drug content of formulation were evaluated for 30 days when stored at 2–8°C. Concentration of solution was measured with a validated method using high performance liquid chromatography (HPLC) coupled with an absorbance UV detector. Equally, microbiological stability was performed. Results The remaining imatinib concentration was at least 95% of the initial concentration after 30 days stored in fridge temperature. No changes were observed regarding the physical properties of the formulation during the study period. Conclusions The stability study showed that the imatinib oral solution at a concentration of 30 mg/mL provides an alternative option at the commercial tablet dosage forms for pediatric patients and patients who have difficulties to swallow.


2021 ◽  
Vol 18 ◽  
Author(s):  
Qurratul Ain Zakirah Mohd Zamram ◽  
Hannis Fadzillah Mohsin ◽  
Mashani Mohamad Mohamad ◽  
Nurul Aqmar Mohamad Nor Hazalin ◽  
Khuriah Abdul Hamid

Aim: Formulating topical products for skin delivery has always been a challenge for pharmaceutical scientists to fulfil good formulation criteria. Despite the challenges, gel-based drug delivery offers some advantages such that it is non-invasive, painless, avoidance of the first-pass metabolism and has satisfactory patient compliance. Objectives: In this study, Chromolaena odorata gel and quercetin gel (bioactive flavonoid compound) were successfully formulated and compared with placebo and conventional wound aid gel. The chromatographic profilling was conducted to screen the presence of phytoconstituents. Subsequently, all formulated gels were subjected to physical characteristic and stability study. Methods: Reverse Phase High-Performance Liquid Chromatography (RP-HPLC) of C.odorata methanolic leaves extract shows a distinct compound separation at retention time 8.4min to 34.8 min at 254nm. All gels were characterised by evaluating their rheological properties including storage modulus, loss modulus and plastic viscosity. Besides, texture analysis was performed to measure the gels’ firmness, consistency, cohesiveness, and viscosity index. Results: From the observation, C. odorata gel demonstrated better spreadability as compared to the other gels, which acquired less work and favourable to be applied onto the skin. Moreover, C. odorata gel showed no changes in organoleptic properties and proven to be stable after 30 days of accelerated stability study at 40°C ± 2°C with relative humidity (RH) of 75%± 5%. Conclusion: C. odorata gel has shown to be stable, reflecting the combination of materials used in the formulation, which did not degrade throughout the study. This work suggests the potential of this gel as a vehicle to deliver the active ingredients of C. odorata to the skin, which can be further explored as a topical application in antimicrobial wound management or other skin diseases study.


1989 ◽  
Vol 134 (2) ◽  
pp. 433-436 ◽  
Author(s):  
V. Ščasnár ◽  
M. Zemánek ◽  
L. Šoltés ◽  
M. Lukácsová

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0245372
Author(s):  
Beatrice Kaufmann ◽  
Philippa Boulle ◽  
Flavien Berthou ◽  
Margot Fournier ◽  
David Beran ◽  
...  

Strict storage recommendations for insulin are difficult to follow in hot tropical regions and even more challenging in conflict and humanitarian emergency settings, adding an extra burden to the management of people with diabetes. According to pharmacopeia unopened insulin vials must be stored in a refrigerator (2–8°C), while storage at ambient temperature (25–30°C) is usually permitted for the 4-week usage period during treatment. In the present work we address a critical question towards improving diabetes care in resource poor settings, namely whether insulin is stable and retains biological activity in tropical temperatures during a 4-week treatment period. To answer this question, temperature fluctuations were measured in Dagahaley refugee camp (Northern Kenya) using log tag recorders. Oscillating temperatures between 25 and 37°C were observed. Insulin heat stability was assessed under these specific temperatures which were precisely reproduced in the laboratory. Different commercialized formulations of insulin were quantified weekly by high performance liquid chromatography and the results showed perfect conformity to pharmacopeia guidelines, thus confirming stability over the assessment period (four weeks). Monitoring the 3D-structure of the tested insulin by circular dichroism confirmed that insulin monomer conformation did not undergo significant modifications. The measure of insulin efficiency on insulin receptor (IR) and Akt phosphorylation in hepatic cells indicated that insulin bioactivity of the samples stored at oscillating temperature during the usage period is identical to that of the samples maintained at 2–8°C. Taken together, these results indicate that insulin can be stored at such oscillating ambient temperatures for the usual four–week period of use. This enables the barrier of cold storage during use to be removed, thereby opening up the perspective for easier management of diabetes in humanitarian contexts and resource poor settings.


2016 ◽  
Vol 9 (1) ◽  
pp. 54
Author(s):  
Megha Sharma ◽  
Neeraj Mahindroo

Objective: The objective of the present study was to develop and validate a novel stability indicating reverse phase-high performance liquid chromatography (RP-HPLC) method for determination of β-acetyldigoxin, an active pharmaceutical ingredient (API).Methods: The chromatographic separation was carried out on Agilent Technologies 1200 series HPLC system equipped with photo diode array detector and C-18 (4.6x250 mm, 5 µ) column. The mobile phase consisted of water: acetonitrile (65:35 v/v), delivered at a flow rate of 1.5 ml/min and eluents were monitored at 225 nm.Results: The retention time of β-acetyldigoxin was 9.2 min. The method was found to be linear (R2= 0.9995) in the range of 31.25-500 µg/ml. The accuracy studies showed the mean percent recovery of 101.02%. LOD and LOQ were observed to be 0.289 µg/ml and 0.965 µg/ml, respectively. The method was found to be robust and system suitability testing was also performed. Forced degradation analysis was carried out under acidic, alkaline, oxidative and photolytic stress conditions. Significant degradation was observed under tested conditions, except for oxidative condition. The method was able to separate all the degradation products within runtime of 20 min and was able to determine β-acetyldigoxin unequivocally in presence of degradation products.Conclusion: The novel, economic, rapid and simple method for analysis of β-acetyldigoxin is reported. The developed method is suitable for routine quality control and its determination as API, and in pharmaceutical formulations and stability study samples.


Author(s):  
KAHTAN J HASSON ◽  
ESRAA G JABAR ◽  
IHAB I ALKHALIFA

Objective: Bisacodyl is a laxative drug used in the treatment of constipation, it is soluble in mineral acids, but it is practically insoluble in water. Therefore, it is very hard task to dissolve bisacodyl in alkaline medium so the objective of this study was the development of proper dissolution method for a new formulation of bisacodyl suppositories in a medium simulated to rectal region. Obviously, most of the bisacodyl suppositories preparation products will yield low percentages of dissolution in the alkaline medium of phosphate buffer pH 7.2. Methods: Preparation inclusion complex of bisacodyl with the solubilizing agent beta-cyclodextrin then incorporated in a suppository base. The quantitative analysis of bisacodyl in suppositories was carried by a developed and validated high-performance liquid chromatography method. Results and Discussion: The dissolution rates for the innovated formulation of bisacodyl complexed with beta-cyclodextrin suppositories were in average of 97.5% and the stored suppositories of this formulation maintained their specified physical and chemical properties along the real stability study. Conclusion: The application of the inclusion complexation technique of bisacodyl with beta-cyclodextrin in the production of suppositories enhances the dissolution rate and improves the stability of suppositories performance.


Author(s):  
T. Stylianopoulos ◽  
A. Yeckel ◽  
J. J. Derby ◽  
X. J. Luo ◽  
M. S. Shephard ◽  
...  

The study of creeping flow in fibrous media is of considerable interest in many biological and biomedical applications. There is little work, however, on permeability calculations in three-dimensional random networks. Computational power is now sufficient to calculate permeabilities directly by constructing artificial fiber networks and simulating flow through them. Even with today’s high-performance computers, however, such an approach would be infeasible for large simulations. It is therefore necessary to develop a correlation based on fiber volume fraction, radius and orientation, preferably by incorporating previous studies on isotropic or structured networks. In this work, the direct calculations were performed, using the finite element method, on networks with varying degrees of orientation, and combinations of results for flow parallel and perpendicular to a single fiber or an array thereof, using a volume averaging theory, were compared to the detailed analysis.


2019 ◽  
Vol 102 (4) ◽  
pp. 1014-1020
Author(s):  
Lisa J Patel ◽  
Manan A Raval ◽  
Samir G Patel ◽  
Archita J Patel

Abstract Background: Ayurvedic medicines help in healing disease with fewer undesirable effects in comparison with an allopathic system of medicine to treat central nervous system (CNS) disorders, as the latter is more expensive. Centella asiatica L. is often used in Ayurvedic formulations for the treatment of CNS disorders. Objective: A stability test using an HPTLC method for the estimation of an important marker asiaticoside (ASI) from C. asiatica powder and marketed formulation was developed. Methods: The marker compound ASI from plant powders and marketed formulations were resolved using toluene–ethyl acetate–methanol–glacial acetic acid (2+7+3+1, v/v/v/v) as the mobile phase and then was derivatized. The plant powder and marketed formulation were also subjected to stability studies. Results: The Rf value of ASI was found in range of 0.43–0.47 for the standard ASI, plant powder, and marketed formulation. It was found that the plant powder and formulation exhibited first-order degradation kinetics. Conclusions: The contents of ASI in the formulation (Churna) and its flow characters reduced at the end of the 6 months during an accelerated stability study. The developed method can be used to quantify ASI in the presence of its degradation products. Highlights: The developed method helps in determining batch to batch variation in the content of ASI in herbal formulations.


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