scholarly journals Influence of the span 80/Gelatin B combination on the formulation and stabilization of Argan oil-in-water emulsions

2020 ◽  
Vol 11 (4) ◽  
pp. 7182-7191
Author(s):  
Aicha Fahry ◽  
Yassir El Alaoui ◽  
Younes Rahali ◽  
Nawal Charkaoui ◽  
Abdelkader Laatiris
Keyword(s):  
Lipid Phase ◽  
Type B ◽  
Sorbitan Monooleate ◽  
Simultaneous Application ◽  
Stability Properties ◽  
Argan Oil ◽  
Oil In Water ◽  
Span 80 ◽  
The Stability ◽  
Droplet Charge

The present study aims to evaluate the effect of the combination of a linear protein: Gelatin type B and an oil-soluble emulsifier Span 80 (sorbitan monooleate) in the stabilization of argan oil-in-water emulsions. For this purpose, the emulsifiying properties of Gelatin itself with Argan oil as lipid phase were investigated first, by preparing oil-in-water (O/W) emulsions containing 10  wt%.  Argan oil and varying Gelatin concentrations (0.5-2 % w/w), we have also formulated Argan O/W emulsions by span 80 alone at levels ranging from 1 to 6 wt%. Subsequentely, we explored the influence of the simultaneous application of the Span 80 and the gelatine on the stability properties and on the droplets size of Argan O/W emulsions, using different mixtures of the two emulsifiers. We compared the stability properties (flocculation, creaming, and phase separation) of argan O/W emulsions prepared with type B gelatine as the only emulsifier with those of emulsions prepared with span 80 and mixture of gelatin/Span. For stable emulsions, our analysis was completed with measurement of droplets size and Zeta Potential. Finally, all of the experimental results and the storage time showed that the emulsions prepared by 10 wt% argan oil and 2 (w/w) % Gelatin+ 3 wt% Span 80 were the most stable with optimum conditions for minimal creaming, small droplets size (size <1µm) and high net droplet charge (absolute value of ZP > 23). The presence of span 80 in coexistence with gelatin, even in small quantitiees, has a profound influence on the stability of the argan O/W emulsions.

Emulsification of Water and Pyrolysis Oil by Sorbitol Derivative Surfactants

2014 ◽  
Vol 633-634 ◽  
pp. 537-540 ◽  
Author(s):  
Prakorn Kittipoomwong ◽  
Monpilai Narasingha
Keyword(s):  
Surfactant Concentration ◽  
Pyrolysis Oil ◽  
Stable Emulsion ◽  
Sorbitan Monooleate ◽  
Oil Emulsion ◽  
Hydrophilic Lipophilic Balance ◽  
Average Water ◽  
Span 80 ◽  
Oil Emulsions ◽  
The Stability

Effects of sorbitol derivative surfactants on the stability of pyrolysis oil emulsion prepared from plastic waste were experimentally investigated. The water-pyrolysis oil mixture emulsified by Sorbitan monooleate (Span 80) surfactant is more stable than the water-in-oil emulsions prepared by other Sorbitol derivative surfactants which have lower hydrophilic-lipophilic balance (HLB) numbers. The Span 80 concentration of 1.5% by volume was found to produce the most stable emulsion and the smallest average water droplet. This optimal surfactant concentration is the same as critical micelle concentration.

scholarly journals Stabilization of crude oil emulsions using different surfactants

2018 ◽  
Vol 1 (1) ◽  
pp. 23-26
Author(s):  
Sweeta Akbari ◽  
Abdurahman Hamid Nour
Keyword(s):  
Crude Oil ◽  
Emulsion Stability ◽  
Oil In Water ◽  
Span 80 ◽  
Oil Emulsions ◽  
The Stability ◽  
Triton X

Emulsions can be found in different industries such as petroleum, food, cosmetic and pharmaceutics. Generally, there are two types of emulsions in petroleum industries: water-in-oil (W/O) and oil-in-water (O/W). The aim of this research was to evaluate the stability of W/O emulsions using different emulsifiers such as Span 80, Span 83, Triton-x-100, DEA, and LSWR with different concentrations (1.5 and 2.5) vol%. All the emulsions were prepared at (20-80) vol% and 2000 rpm. The result of this study showed that the most stable emulsions were prepared by Span 80. However, LSWR formed the most unstable emulsions. In addition, it was also found that the concentration of emulsifier can significantly affect the emulsion stability.

scholarly journals Influence of Whey Protein Micro-Gel Particles and Whey Protein Micro-Gel Particles-Xanthan Gum Complexes on the Stability of O/W Emulsions

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2301
Author(s):  
Man Zhang ◽  
Bin Liang ◽  
Hongjun He ◽  
Changjian Ji ◽  
Tingting Cui ◽  
...  
Keyword(s):  
Oxidative Stability ◽  
Whey Protein ◽  
High Speed ◽  
Xanthan Gum ◽  
Physical Stability ◽  
Theoretical Support ◽  
Gel Particles ◽  
Oil In Water ◽  
The Stability ◽  
The Impact

Appropriate pretreatment of proteins and addition of xanthan gum (XG) has the potential to improve the stability of oil-in-water (O/W) emulsions. However, the factors that regulate the enhancement and the mechanism are still not clear, which restricts the realization of improving the emulsion stability by directional design of its structure. Therefore, the effects of whey protein micro-gel particles (WPMPs) and WPMPs-XG complexes on the stability of O/W emulsion were investigated in this article to provide theoretical support. WPMPs with different structures were prepared by pretreatment (controlled high-speed shear treatment of heat-set WPC gels) at pH 3.5–8.5. The impact of initial WPC structure and XG addition on Turbiscan Indexes, mean droplet size and the peroxide values of O/W emulsions was investigated. The results indicate that WPMPs and XG can respectively inhibit droplet coalescence and gravitational separation to improve the physical stability of WPC-stabilized O/W emulsions. The pretreatment significantly enhanced the oxidative stability of WPC-stabilized O/W emulsions. The addition of XG did not necessarily enhance the oxidative stability of O/W emulsions. Whether the oxidative stability of the O/W emulsion with XG is increased or decreased depends on the interface structure of the protein-XG complex. This study has significant implications for the development of novel structures containing lipid phases that are susceptible to oxidation.

scholarly journals Polymeric Micelles for the Enhanced Deposition of Hydrophobic Drugs into Ocular Tissues, without Plasma Exposure

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 744
Author(s):  
Ijeoma F. Uchegbu ◽  
Jan Breznikar ◽  
Alessandra Zaffalon ◽  
Uche Odunze ◽  
Andreas G. Schätzlein
Keyword(s):  
Polymeric Micelles ◽  
Rabbit Model ◽  
Penetration Enhancer ◽  
Hydrophobic Drugs ◽  
Ocular Tissues ◽  
Ocular Penetration ◽  
Self Assembling ◽  
Similar Dose ◽  
Oil In Water ◽  
The Stability

Commercial topical ocular formulations for hydrophobic actives rely on the use of suspensions or oil in water emulsions and neither of these formulation modalities adequately promote drug penetration into ocular tissues. Using the ocular relevant hydrophobic drug, cyclosporine A (CsA), a non-irritant ocular penetration enhancer is showcased, which may be used for the formulation of hydrophobic actives. The activity of this penetration enhancer is demonstrated in a healthy rabbit model. The Molecular Envelope Technology (MET) polymer (N-palmitoyl-N-monomethyl-N,N-dimethyl-N,N,N-trimethyl-6-O-glycolchitosan), a self-assembling, micelle-forming polymer, was used to formulate CsA into sterile filtered nanoparticulate eye drop formulations and the stability of the formulation tested. Healthy rabbits were dosed with a single dose of a MET–CsA (NM133) 0.05% formulation and ocular tissues analyzed. Optically clear NM133 formulations were prepared containing between 0.01–0.1% w/v CsA and 0.375–0.75% w/v MET polymer. NM133 0.01%, NM133 0.02% and NM133 0.05% were stable for 28 days when stored at refrigeration temperature (5–6 °C) and room temperature (16–23 °C), but there was evidence of evaporation of the formulation at 40 °C. There was no change in drug content when NM133 0.05% was stored for 387 days at 4 °C. On topical dosing to rabbits, corneal, conjunctival and scleral AUC0–24 levels were 25,780 ng.h g−1, 12,046 ng.h g−1 and 5879 ng.h g−1, respectively, with NM133 0.05%. Meanwhile, a similar dose of Restasis 0.05% yielded lower values of 4726 ng.h/g, 4813 ng.h/g and 1729 ng.h/g for the drug corneal, conjunctival and scleral levels, respectively. NM133 thus delivered up to five times more CsA to the ocular surface tissues when compared to Restasis. The MET polymer was non-irritant up to a concentration of 4% w/v. The MET polymer is a non-irritant ocular penetration enhancer that may be used to deliver hydrophobic drugs in optically clear topical ocular formulations.

scholarly journals Velocity and acceleration level inverse kinematic calculation alternatives for redundant manipulators

Meccanica ◽  
2021 ◽  
Author(s):  
Dóra Patkó ◽  
Ambrus Zelei
Keyword(s):  
Degrees Of Freedom ◽  
Direct Method ◽  
Tracking Error ◽  
Inverse Kinematic ◽  
Linear Feedback ◽  
Joint Position ◽  
Stability Properties ◽  
Acceleration Level ◽  
Error Elimination ◽  
The Stability

AbstractFor both non-redundant and redundant systems, the inverse kinematics (IK) calculation is a fundamental step in the control algorithm of fully actuated serial manipulators. The tool-center-point (TCP) position is given and the joint coordinates are determined by the IK. Depending on the task, robotic manipulators can be kinematically redundant. That is when the desired task possesses lower dimensions than the degrees-of-freedom of a redundant manipulator. The IK calculation can be implemented numerically in several alternative ways not only in case of the redundant but also in the non-redundant case. We study the stability properties and the feasibility of a tracking error feedback and a direct tracking error elimination approach of the numerical implementation of IK calculation both on velocity and acceleration levels. The feedback approach expresses the joint position increment stepwise based on the local velocity or acceleration of the desired TCP trajectory and linear feedback terms. In the direct error elimination concept, the increment of the joint position is directly given by the approximate error between the desired and the realized TCP position, by assuming constant TCP velocity or acceleration. We investigate the possibility of the implementation of the direct method on acceleration level. The investigated IK methods are unified in a framework that utilizes the idea of the auxiliary input. Our closed form results and numerical case study examples show the stability properties, benefits and disadvantages of the assessed IK implementations.

scholarly journals Local compactness in approach spaces II

2003 ◽  
Vol 2003 (2) ◽  
pp. 109-117
Author(s):  
R. Lowen ◽  
C. Verbeeck
Keyword(s):  
Stability Properties ◽  
Local Compactness ◽  
The Stability ◽  
Approach Spaces

This paper studies the stability properties of the concepts of local compactness introduced by the authors in 1998. We show that all of these concepts are stable for contractive, expansive images and for products.

On the stability properties of a third order system

1968 ◽  
Vol 78 (1) ◽  
pp. 91-103 ◽  
Author(s):  
G. P. Szegö ◽  
C. Olech ◽  
A. Cellina
Keyword(s):  
Order System ◽  
Third Order ◽  
Stability Properties ◽  
The Stability

scholarly journals Assessment of Fennel Oil Microfluidized Nanoemulsions Stabilization by Advanced Performance Xanthan Gum

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 693
Author(s):  
Rubén Llinares ◽  
Pablo Ramírez ◽  
José Antonio Carmona ◽  
Luis Alfonso Trujillo-Cayado ◽  
José Muñoz
Keyword(s):  
Essential Oil ◽  
Rheological Properties ◽  
Xanthan Gum ◽  
Mechanical Energy ◽  
Physical Stability ◽  
Processing Condition ◽  
Oil In Water ◽  
Mechanical Spectra ◽  
The Stability ◽  
Fennel Oil

In this work, nanoemulsion-based delivery system was developed by encapsulation of fennel essential oil. A response surface methodology was used to study the influence of the processing conditions in order to obtain monomodal nanoemulsions of fennel essential oil using the microchannel homogenization technique. Results showed that it was possible to obtain nanoemulsions with very narrow monomodal distributions that were homogeneous over the whole observation period (three months) when the appropriate mechanical energy was supplied by microfluidization at 14 MPa and 12 passes. Once the optimal processing condition was established, nanoemulsions were formulated with advanced performance xanthan gum, which was used as both viscosity modifier and emulsion stabilizer. As a result, more desirable results with enhanced physical stability and rheological properties were obtained. From the study of mechanical spectra as a function of aging time, the stability of the nanoemulsions weak gels was confirmed. The mechanical spectra as a function of hydrocolloid concentration revealed that the rheological properties are marked by the biopolymer network and could be modulated depending on the amount of added gum. Therefore, this research supports the role of advanced performance xanthan gum as a stabilizer of microfluidized fennel oil-in-water nanoemulsions. In addition, the results of this research could be useful to design and formulate functional oil-in-water nanoemulsions with potential application in the food industry for the delivery of nutraceuticals and antimicrobials.

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