scholarly journals Formulation and Evaluation of Ethosomal Nanoparticles of Avobenzone for Improved Sunscreen Efficacy

2021 ◽  
Vol 70 (1) ◽  
Author(s):  
Sumit Kumar Nagle ◽  
Mansi Gupta ◽  
Deepak Kumar Basedia ◽  
Dubey B.K.
Keyword(s):  
Propylene Glycol ◽  
Room Temperature ◽  
Ethanol Concentration ◽  
Sun Protection ◽  
Irregular Shape ◽  
Good Protection ◽  
In Vitro Permeation ◽  
Egg Membrane ◽  
The Stability

Ethosomes entrapping avobenzone were prepared using cold method and the effect of varying concentration of ethanol was considered for obtaining an optimized formulation. Lecithin (2%w/w) was used as the phospholipid to provide the structure to the vesicles and propylene glycol (10%) was used as the permeating agent. The vesicles were found to be of spherical to irregular shape ranged from 1.11 µm to 1.6 µm in size. The drug entrapment in the ethosomes was studied by analyzing the unentrapped drug spectrophotometrically. The in vitro permeation study suggested that the maximum permeation in the egg membrane occurred in AET3 (0.40 mg/cm2) with 30% ethanol concentration. It was observed that only about 2% degradation occurred at room temperature and all formulations were almost stable at 8° and 4° with only 1.3% degradation of avobenzone thereby proving the stability of the developed system. The best ethosomal formulation (AET3) was incorporated into gel base to obtain sunscreen gels and the results revealed a good protection of the ethosomal gel when 2% carbopol was used as the gelling base. It could be concluded that incorporation of avobenzone in the ethosomal carrier and formulating the same as gel formulation might help in reducing the dose of avobenzone as well as improving the sunscreen efficacy (sun protection over enhanced duration).

scholarly journals The Formation of Chitosan-Coated Rhamnolipid Liposomes Containing Curcumin: Stability and In Vitro Digestion

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 560
Author(s):  
Wei Zhou ◽  
Ce Cheng ◽  
Li Ma ◽  
Liqiang Zou ◽  
Wei Liu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Functional Foods ◽  
Positive Charge ◽  
Physical Stability ◽  
In Vitro Digestion ◽  
Salt Addition ◽  
High Transformation ◽  
Liposomal Delivery ◽  
The Stability

There is growing interest in developing biomaterial-coated liposome delivery systems to improve the stability and bioavailability of curcumin, which is a hydrophobic nutraceutical claimed to have several health benefits. The curcumin-loaded rhamnolipid liposomes (Cur-RL-Lips) were fabricated from rhamnolipid and phospholipids, and then chitosan (CS) covered the surface of Cur-RL-Lips by electrostatic interaction to form CS-coated Cur-RL-Lips. The influence of CS concentration on the physical stability and digestion of the liposomes was investigated. The CS-coated Cur-RL-Lips with RL:CS = 1:1 have a relatively small size (412.9 nm) and positive charge (19.7 mV). The CS-coated Cur-RL-Lips remained stable from pH 2 to 5 at room temperature and can effectively slow the degradation of curcumin at 80 °C; however, they were highly unstable to salt addition. In addition, compared with Cur-RL-Lips, the bioavailability of curcumin in CS-coated Cur-RL-Lips was relatively high due to its high transformation in gastrointestinal tract. These results may facilitate the design of a more efficacious liposomal delivery system that enhances the stability and bioavailability of curcumin in nutraceutical-loaded functional foods and beverages.

scholarly journals PREPARATION, CHARACTERIZATION AND ANTIOXIDANT ACTIVITY OF XANTHONE-LOADED MAKING (HODGSONIA HETEROCLITA) MICROEMULSIONS

2017 ◽  
Vol 9 (3) ◽  
pp. 262
Author(s):  
Sunee Chansakaow ◽  
Panee Sirisa-ard ◽  
Ruttiros Khonkarn
Keyword(s):  
Antioxidant Activity ◽  
Propylene Glycol ◽  
Droplet Size ◽  
Tween 80 ◽  
Screw Press ◽  
Pharmaceutical Applications ◽  
Microemulsion Based Gel ◽  
Release Study ◽  
The Stability

Objective: The aim of this study was to incorporate xanthone into Making (Hodgsonia heteroclita) microemulsions and to evaluate the antioxidant activity of the formulations.Methods: Making oil was obtained from the seed of Hodgsonia heteroclite by a screw press machine. The solubility of xanthone in various oils, surfactants, and co-surfactants was investigated. Stable Making microemulsion and microemulsion-based gel were simultaneously loaded with xanthone. Finally, an in vitro xanthone release study was carried out and antioxidant activity was determined.Results: The optimal formulations of the Making microemulsion consisted of Making oil, capryol 90, tween 80, propylene glycol, and water. The average droplet size of xanthone-loaded Making microemulsion was around 110–130 nm. It was found that the stability of the xanthone-loaded Making microemulsion-based gel was higher than the xanthone-loaded Making microemulsion. Besides, the release of xanthone from the Making microemulsion-based gel was lower than that of the Making microemulsion. Moreover, it was found that the antioxidant activity of both xanthone-loaded Making microemulsion (TEAC and EC values of 9.8 mmol/mg and 14.8 mmol/mg, respectively) and microemulsion-based gel (TEAC and EC values of 9.4 mmol/mg and 18.5 mmol/mg, respectively) remained high even after extended storage conditions.Conclusion: It was concluded that Making oil is an attractive material to deliver xanthone in pharmaceutical applications.

scholarly journals Effect of Doxycycline Microencapsulation on Buccal Films: Stability, Mucoadhesion and In Vitro Drug Release

Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 51
Author(s):  
Venu Gopal Reddy Patlolla ◽  
Nikolina Popovic ◽  
William Peter Holbrook ◽  
Thordis Kristmundsdottir ◽  
Sveinbjörn Gizurarson
Keyword(s):  
Tensile Strength ◽  
Room Temperature ◽  
In Vitro Release ◽  
Sodium Thiosulfate ◽  
Scanning Calorimetry ◽  
In Vitro Drug Release ◽  
Metalloproteinase Inhibitors ◽  
The Stability ◽  
Buccal Films

The aim of this work was to stabilize doxycycline in mucoadhesive buccal films at room temperature (25 °C). Since doxycycline is susceptible to degradation such as oxidation and epimerization, tablets are currently the only formulation that can keep the drug fully stable at room temperature, while liquid formulations are limited to refrigerated conditions (4 °C). In this study, the aim was to make formulations containing subclinical (antibiotic) doxycycline concentration that can act as matrix metalloproteinase inhibitors (MMPI) and can be stored at temperatures such as 25 °C. Here, doxycycline was complexed with excipients using three techniques and entrapped into microparticles that were stored at 4 °C, 25 °C and 40 °C. Effect of addition of precomplexed doxycycline microparticles on films: stability mucoadhesion capacity, tensile strength, swelling index and in vitro release was studied. The complexation efficiency between drug-excipients, microparticles and films was studied using Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Two of the films were found to be stable at 4 °C but the film containing microparticle composed of precomplexed doxycycline with β-cyclodextrin, MgCl2, sodium thiosulfate, HPMC and Eudragit® RS 12.5 was found to be stable at 25 °C until 26 weeks. The addition of microparticles to the films was found to reduce the mucoadhesive capacity, peak detachment force, tensile strength and elasticity, but improved the stability at room temperature.

scholarly journals Presence and Stability of SARS-CoV-2 on Environmental Currency and Money Cards

2021 ◽  
Author(s):  
Colleen Newey ◽  
Abigail T Olausson ◽  
Alyssa Applegate ◽  
Ann Aubrey Reid ◽  
Richard A Robison ◽  
...  
Keyword(s):  
Room Temperature ◽  
Credit Cards ◽  
The United States ◽  
Microbial Pathogens ◽  
Rapid Reduction ◽  
Live Virus ◽  
Brigham Young University ◽  
Contagious Nature ◽  
The Stability

The highly contagious nature of SARS-CoV-2 has led to several studies on the transmission of the virus. A little studied potential fomite of great concern in the community is currency, which has been shown to harbor microbial pathogens in several studies. Since the onset of the COVID-19 pandemic, many businesses in the United States have limited the use of banknotes in favor of credit cards. However, SARS-CoV-2 has shown greater stability on plastic in several studies.  Herein, the stability of SARS-CoV-2 at room temperature on banknotes, money cards and coins was investigated. In vitro studies with live virus suggested SARS-CoV-2 was highly unstable on banknotes, showing an initial rapid reduction in viable virus and no viral detection by 24 hours. In contrast, SARS-CoV-2 was far more stable on money cards with live virus detected after 48 hours. Environmental swabbing of currency and money cards on and near the campus of Brigham Young University supported these results, with no detection of SARS-CoV-2 RNA on banknotes, and a low level on money cards. No viable virus was detected on either. These preliminary results suggest that the use of money cards over banknotes in order to slow the spread of this virus may be ill-advised. These findings should be investigated further through larger environmental studies involving more locations.

scholarly journals Nanoencapsulation of clove oil and study of physico-chemical properties, cytotoxic, haemolytic and antioxidant activities

2020 ◽  
Author(s):  
Pramod G Nagaraju ◽  
Parineeta Sengupta ◽  
C. G. Poornima Priyadarshini ◽  
Pooja J Rao
Keyword(s):  
Room Temperature ◽  
In Vitro Release ◽  
Radical Scavenging ◽  
Tween 80 ◽  
Tween 20 ◽  
Haemolytic Activity ◽  
Clove Oil ◽  
The Stability ◽  
Vitro Release

AbstractThe therapeutic properties of clove oil is known for centuries, however, the pungent nature, chemical instability and low water solubility impose limitations in harnessing its therapeutic potential. Hence, nanoencapsulation of clove oil was performed to overcome the above constraints and control its in-vitro release. The stability of nanoemulsion depends on various factors where the surfactant and its hydrophile/lipofile balance (HLB) play a key role. The non-ionic surfactants Tween 20, 40 and 80 with HLB of 16.7, 15.6 and 15, respectively, were used to study the stability of clove oil nanoemulsion (CON). The creaming index of CON prepared with Tween 20, 40 and 80 was 22.75 and 17.5 and 1.5%, respectively, after 8 days of storage at room temperature. Tween 20 and 40 produced particles > 300 nm while Tween 80 resulted in particles of size ∼150 nm. Transmission electron microscopic image of spray dried CON prepared with Tween 80 showed particle size in the range 150-190 nm after one month of storage at room temperature. The in vitro release studies showed 76% and 42% cumulative release of CON and native clove oil (NC), respectively at pH 7.4. The cellular toxicity of CON was significantly reduced by four fold compared to NC at a concentration of 60 µg/mL when tested on Caco2 cells. Similarly, haemolytic activity on red blood cells revealed less than 10% haemolysis signifying the compatibility of CON for its nutraceutical applications. In addition, CON also exhibited higher in-vitro antioxidant compared to NC as shown by DPPH and ABTS radical scavenging activity. Collectively, we have developed a unique method for NC nanoencapsulation using cost effective polysaccharide (maltodextrin) and surfactant for stabilizing the nanoemulsion for increased bioactivity.

THE STABILITY OF ENDOGENOUS AND EXOGENOUS CORTICOTROPHIN IN RAT PLASMA AS ESTABLISHED BY A BIOASSAY IN INTACT RATS

1968 ◽  
Vol 41 (4) ◽  
pp. 491-497 ◽  
Author(s):  
H. D. PURVES ◽  
NANCY E. SIRETT
Keyword(s):  
Low Temperature ◽  
Room Temperature ◽  
Rat Plasma ◽  
Significant Loss ◽  
Working Standard ◽  
The Stability ◽  
Saline Medium ◽  
Intact Rats

SUMMARY Corticotrophin (ACTH) activity in rat plasma, both endogenous (adrenalectomized rat plasma) and exogenous (International Working Standard, 1962), has been assayed in dexamethasone-treated rats and the stability studied under various conditions of storage. Exogenous ACTH added to rat plasma and assayed immediately had only 76% of the activity of the same ACTH dissolved in gelatine acid saline medium. This difference is ascribed to the effects of the medium and not to inactivation. When allowance was made for the effects of the medium on potency, added ACTH showed a similar stability on incubation or storage to endogenous ACTH. For endogenous ACTH the following loss of activity was found in vitro: after 45 min. at 37°, 64%; after 1 day at room temperature, more than 85%; after 1 day at 3°, 58%. No loss of potency was detected on storage at −17° for 18 months. It is concluded that plasma can be frozen, stored at low temperature, and thawed without significant loss of corticotrophic potency provided that the blood is chilled as soon as drawn and the subsequent operations performed expeditiously.

The Preparation of (E)-Resveratrol Nanoemulsion and In Vitro Release

2011 ◽  
Vol 236-238 ◽  
pp. 2357-2361 ◽  
Author(s):  
Yue Zhang ◽  
Jun Gang Gao ◽  
Dan Peng Ma
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Propylene Glycol ◽  
Ternary Phase ◽  
Test Results ◽  
Mass Ratio ◽  
Ternary Phase Diagrams ◽  
The Mean ◽  
The Stability

Here a novel procedure to prepare stable (E)-resveratrol nanoemulsion is reported. The optimum (E)-resveratrol nanoemulsion formulation was sifted based on the pseudo ternary phase diagrams and particle size distribution. An optimized prescription was given as (E)-resveratrol 0.35%, EL-40 22.6%, 1,2-propylene glycol 5.03%, IPM 9.21% and water 62.81% (mass ratio), with the mean particle size 47.3 nm. The morphology of the (E)-resveratrol nanoemulsion was characterized by TEM. The test results demonstrate that the nanoemulsion could dramatically improve the stability and release of (E)-resveratrol.

scholarly journals The function of intermediate filaments in cell shape and cytoskeletal integrity.

1996 ◽  
Vol 134 (4) ◽  
pp. 971-983 ◽  
Author(s):  
R D Goldman ◽  
S Khuon ◽  
Y H Chou ◽  
P Opal ◽  
P M Steinert
Keyword(s):  
Cell Shape ◽  
Room Temperature ◽  
Specific Method ◽  
Actin Stress Fiber ◽  
Cultured Fibroblasts ◽  
Fiber Networks ◽  
Molar Ratios ◽  
Disassembly Process ◽  
The Stability

This study describes the development and use of a specific method for disassembling intermediate filament (IF) networks in living cells. It takes advantage of the disruptive effects of mimetic peptides derived from the amino acid sequence of the helix initiation 1A domain of IF protein chains. The results demonstrate that at 1:1 molar ratios, these peptides disassemble vimentin IF into small oligomeric complexes and monomers within 30 min at room temperature in vitro. Upon microinjection into cultured fibroblasts, these same peptides induce the rapid disassembly of IF networks. The disassembly process is accompanied by a dramatic alteration in cell shape and the destabilization of microtubule and actin-stress fiber networks. These changes in cell shape and IF assembly states are reversible. The results are discussed with respect to the roles of IF in cell shape and the maintenance of the integrity and mechanical properties of the cytoplasm, as well as the stability of the other major cytoskeletal systems.

Formation and Structure of Casein Micelles in Lactating Mammary Tissue

1970 ◽  
Vol 28 ◽  
pp. 150-151
Author(s):  
Robert J. Carroll ◽  
Marvin P. Thompson ◽  
Harold M. Farrell
Keyword(s):  
Size Distribution ◽  
G Protein ◽  
Milk Proteins ◽  
Mammary Tissue ◽  
Colloidal System ◽  
Casein Micelles ◽  
The Stability

Milk is an unusually stable colloidal system; the stability of this system is due primarily to the formation of micelles by the major milk proteins, the caseins. Numerous models for the structure of casein micelles have been proposed; these models have been formulated on the basis of in vitro studies. Synthetic casein micelles (i.e., those formed by mixing the purified αsl- and k-caseins with Ca2+ in appropriate ratios) are dissimilar to those from freshly-drawn milks in (i) size distribution, (ii) ratio of Ca/P, and (iii) solvation (g. water/g. protein). Evidently, in vivo organization of the caseins into the micellar form occurs in-a manner which is not identical to the in vitro mode of formation.

Sign in / Sign up

Export Citation Format

Share Document