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 New β-Carotene-Chitooligosaccharides Complexes for Food Fortification: Stability Study

Foods ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 765 ◽  
Author(s):  
Alma Bockuviene ◽  
Jolanta Sereikaite
Keyword(s):  
Freeze Drying ◽  
Stability Study ◽  
Food Fortification ◽  
Kinetics Parameters ◽  
Long Term Stability ◽  
First Order Kinetics ◽  
The Stability ◽  
Β Carotene ◽  
Carotene Degradation

The application of β-carotene in food industry is limited due to its chemical instability. The drawback may be overcome by designing new delivery systems. The stability of β-carotene complexed with chitooligosaccharides by kneading, freeze-drying and sonication methods was investigated under various conditions. The first-order kinetics parameters of the reaction of β-carotene degradation were calculated. The complexation improved the stability of β-carotene at high temperatures and ensured its long-term stability in the dark at 4 °C and 24 °C, and in the light at 24 °C. In water solutions, the best characteristics were exhibited by the complexes prepared by freeze-drying and sonication methods. In the powder form, the complexes retained their colour for the period of the investigation of four months. The calculated total colour differences of the complexes were qualified as appreciable, detectable by ordinary people, but not large. Therefore, β-carotene-chitooligosaccharides complexes could be used as a new delivery system suitable for food fortification.

scholarly journals Bio-analytical Approach for Stability Studies of Bendroflumethiazide Materials

2021 ◽  
pp. 195-203
Author(s):  
B. Veeraswami ◽  
V. M. K. Naveen
Keyword(s):  
Stability Study ◽  
Stability Studies ◽  
Dry Extract ◽  
Long Term Stability ◽  
Analytical Stability ◽  
Ich Guidelines ◽  
The Stability ◽  
Efficacy Prediction

In this paper a comprehensive study of stability related, and evidence based best practices of Bio-analytical stability on Bendroflumethiazide drug samples are studied. The proposed approach is very significant and essential for the drugs development process address the specify the acceptancy, purity, efficacy, prediction of strength and quality of the drugs. The stability study constituents several methods like Bench-Top, Auto-sampler, Freeze-Thaw, Dry-extract, Wet-extract, Short-term, long-Term stability studies at relative intervals results the complete stability information about the drug under the proposed and validated method. There ported out comes of this methos shows this drug have good stability according to ICH guidelines.

scholarly journals Do Ophthalmic Solutions of Amphotericin B Solubilised in 2-Hydroxypropyl-γ-Cyclodextrins Possess an Extended Physicochemical Stability?

Pharmaceutics ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 786
Author(s):  
Philip Chennell ◽  
Mouloud Yessaad ◽  
Florence Abd El Kader ◽  
Mireille Jouannet ◽  
Mathieu Wasiak ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Breakdown Product ◽  
Eye Drops ◽  
Chromatography Method ◽  
Term Stability ◽  
Long Term Stability ◽  
The Stability ◽  
Ophthalmic Solutions

Fungal keratitis is a sight-threatening disease for which amphotericin B eye drops is one of the front-line treatments. Unfortunately, there are currently no commercial forms available, and there is little data concerning the long-term stability of compounded formulations based on intravenous dosages forms. New formulations of amphotericin B ophthalmic solutions solubilised with γ-cyclodextrins have shown promising in-vitro results, but stability data is also lacking. The objective of this study was therefore to investigate the stability of a formulation of ready-to-use amphotericin B solubilised in 2-hydroxypropyl-γ-cyclodextrins (AB-HP-γ-CD), for 350 days. An amphotericin B deoxycholate (ABDC) formulation was used as a comparator. Analyses used were the following: visual inspection, turbidity, osmolality and pH measurements, amphotericin B quantification by a stability-indicating liquid chromatography method, breakdown product research, and sterility assay. AB-HP-γ-CD formulation showed signs of chemical instability (loss of amphotericin B) after 28 and 56 days at 25 °C and 5 °C. Adding an antioxidant (ascorbic acid) to the formulation did not improve stability. ABDC formulation showed signs of physical instability (increased turbidy and amphotericin B precipitation) after 28 days and 168 days at 25 °C and 5 °C. As such, AB-HP-γ-CD formulation does not provide long-term stability for ophthalmic amphotericin B solutions.

scholarly journals Separation of Gases by Membranes: The Effects of Pollutants on the Stability of Membranes

2017 ◽  
Vol 45 (1) ◽  
pp. 5-8
Author(s):  
Nándor Nemestóthy
Keyword(s):  
Polymer Membranes ◽  
Measuring System ◽  
Nitrogen Gas ◽  
Long Term Stability ◽  
Separation Membranes ◽  
Gas Separation Membranes ◽  
Separation Of Gases ◽  
Multichannel Measuring ◽  
The Stability

Abstract The long-term stability of membranes is determined mainly by their sensitivity to pollutants. Their stability was tested using a novel, multichannel measuring system, which is based on pressure differences. This measuring system is suitable to determine the changes in permeability of polymer membranes. The damaging effects of H2S, BTX and n-dodecane were investigated in terms of polyimide gas separation membranes using nitrogen gas.

scholarly journals Stability study of nasal powder formulation containing nanosized lamotrigine

2020 ◽  
Vol 90 (1) ◽  
pp. 27-31
Author(s):  
Péter Gieszinger ◽  
Gábor Katona ◽  
Piroska Szabó-Révész ◽  
Rita Ambrus
Keyword(s):  
Local Effect ◽  
Stability Study ◽  
System Effect ◽  
In Vitro Drug Release ◽  
Long Term Stability ◽  
The Past ◽  
The Stability ◽  
Degradation Effect

Drug administration through the nose offers great possibilities which have been discovered in the past few decades. Besides the most known local effect, systemic and central nervous system effect is also available, the administration is non-painful and the degradation effect of the gastrointestinal tract can be avoided. Amongst the nasal formulations, powders have become more popular as their stability is favorable compared to the liquid formulations and a higher dose can be administered in powder form. The quality insurance and stability of the products in the pharmaceutical field have gained considerable attention in the last decades. Due to this fact, the aim was to execute a long-term stability study of a previously developed, nanosized lamotrigine (LAM) containing nasal powder (NP) formulation. The results of the stability test showed that the NP formulation preserved its key properties (particle size, morphology, structure and in vitro drug release) after 6 months of storage.

The Stability of the WHO Reference Thromboplastin NIBS & C 67/40

1979 ◽  
Vol 42 (04) ◽  
pp. 1135-1140 ◽  
Author(s):  
G I C Ingram
Keyword(s):  
Human Brain ◽  
Collaborative Study ◽  
Calibration Constant ◽  
Long Term Stability ◽  
Freeze Dried ◽  
Show Evidence ◽  
Human Material ◽  
Reference Preparation ◽  
The Stability

SummaryThe International Reference Preparation of human brain thromboplastin coded 67/40 has been thought to show evidence of instability. The evidence is discussed and is not thought to be strong; but it is suggested that it would be wise to replace 67/40 with a new preparation of human brain, both for this reason and because 67/40 is in a form (like Thrombotest) in which few workers seem to use human brain. A �plain� preparation would be more appropriate; and a freeze-dried sample of BCT is recommended as the successor preparation. The opportunity should be taken also to replace the corresponding ox and rabbit preparations. In the collaborative study which would be required it would then be desirable to test in parallel the three old and the three new preparations. The relative sensitivities of the old preparations could be compared with those found in earlier studies to obtain further evidence on the stability of 67/40; if stability were confirmed, the new preparations should be calibrated against it, but if not, the new human material should receive a calibration constant of 1.0 and the new ox and rabbit materials calibrated against that.The types of evidence available for monitoring the long-term stability of a thromboplastin are discussed.

Preparation and Long-Term Stability Study of Steel Fiber/Graphite Conductive Concrete

2016 ◽  
Vol 680 ◽  
pp. 361-364 ◽  
Author(s):  
Jun Du ◽  
Cheng Tang ◽  
Bo Jia ◽  
De Zhang ◽  
Qiang Miao
Keyword(s):  
Corrosion Resistance ◽  
Steel Fiber ◽  
Stability Study ◽  
Soil Resistivity ◽  
Grounding Resistance ◽  
Term Stability ◽  
Long Term Stability ◽  
Conductive Fillers ◽  
The Common

The steel fiber/graphite conductive concrete is applied in power system grounding. In high soil resistivity regions, the common methods for reducing the grounding resistance are not practical. It is difficult for grounding resistance of substations to meet the requirements of working earthing and safety earthing. In order to solve this problem, a steel fiber/graphite conductive concrete is developed in this paper. Steel fiber and graphite are added as conductive fillers. The long-term stability of the steel fiber/graphite conductive concrete is studied. The experiment results show that steel fiber/graphite conductive concrete not only maintains excellent conductivity, but also has good mechanical strength and corrosion resistance in 300 days.

LONG-TERM STABILITY ANALYSIS OF ACOUSTIC ABSORBING BOUNDARY CONDITIONS

2013 ◽  
Vol 23 (11) ◽  
pp. 2129-2154 ◽  
Author(s):  
HÉLÈNE BARUCQ ◽  
JULIEN DIAZ ◽  
VÉRONIQUE DUPRAT
Keyword(s):  
Stability Analysis ◽  
Boundary Conditions ◽  
Absorbing Boundary Conditions ◽  
Computational Domain ◽  
Acoustic Wave Equation ◽  
Absorbing Boundary ◽  
Term Stability ◽  
Long Term Stability ◽  
The Stability

This work deals with the stability analysis of a one-parameter family of Absorbing Boundary Conditions (ABC) that have been derived for the acoustic wave equation. We tackle the problem of long-term stability of the wave field both at the continuous and the numerical levels. We first define a function of energy and show that it is decreasing in time. Its discrete form is also decreasing under a Courant–Friedrichs–Lewy (CFL) condition that does not depend on the ABC. Moreover, the decay rate of the continuous energy can be determined: it is exponential if the computational domain is star-shaped and this property can be illustrated numerically.

A Review of Preparation and Tribological Applications of Pickering Emulsion

2021 ◽  
pp. 1-27
Author(s):  
Yichen Bao ◽  
Kai Liu ◽  
Quan Zheng ◽  
Lulu Yao ◽  
Yufu Xu
Keyword(s):  
Pickering Emulsion ◽  
Solid Particles ◽  
Preparation Methods ◽  
Factors Affecting ◽  
Long Term Stability ◽  
New Strategy ◽  
New Type ◽  
The Stability ◽  
Near Future

Abstract Pickering emulsion is a new type of stable emulsion made by ultra-fine solid particles instead of traditional surfactants as stabilizers, which has received widespread attention in recent years. The preparation methods of stator-rotor homogenization, high-pressure homogenization, and ultrasonic emulsification were compared with others in this work. The main factors affecting the stability of Pickering emulsion are the surface humidity of the solid particles, the polarity of the oil phase, and the oil-water ratio. These factors could affect the nature of the solid particles, the preparation process of Pickering emulsion and the external environment. Consequently, the long-term stability of Pickering emulsion is still a challenge. The tribological investigations of Pickering emulsion were summarized, and the multifunctional Pickering emulsion shows superior prospects for tribological applications. Moreover, the latest development of Pickering emulsion offers a new strategy for smart lubrication in the near future.

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