Dispersion of Cholesterol in Aqueous Surfactant Solutions: Interpretation of Viscosity Data

Singh, Vimal Sheel; Gaur, Rishika

doi:10.1080/01932698308943376

Cited by 4 publications

(3 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The fact lies in the formation of a fixed number of niosomes at a given amount of vesicle components (surfactant, cholesterol and lecithin), thus having definite entrapment efficiency and the excess drug gets precipitated. [27,31] …”

Section: Optimisation Of the Proniosomal Formulationsmentioning

confidence: 99%

“…The loosely packed membrane was thus formed which showed high permeability. [27] The concentration of cholesterol also plays an important role in the formation and drug entrapment in the vesicles because these molecules house themselves as 'vesicular cement' into the bilayers of the surfactant membranes. [28,29] This mechanism is responsible for the permeability, rigidity and stability of the niosomes vesicles.…”

Section: Optimisation Of the Proniosomal Formulationsmentioning

confidence: 99%

See 1 more Smart Citation

Proniosomal gel-mediated transdermal delivery of bromocriptine:in vitroandex vivoevaluation

Lather¹,

Sharma²,

Pandita³

2016

Journal of Experimental Nanoscience

View full text Add to dashboard Cite

Vesicular systems endow large opportunities for the transdermal delivery of therapeutics. The present study was designed to investigate the potential of a novel class of vesicular system 'proniosome' as a carrier for transdermal delivery of bromocriptine (BCT). Proniosome formulations were prepared by the coacervationphase separation method and the influence of factors like surfactant type and its amount, lipid concentration, cholesterol amount and drug content were studied. Span 60 was the most appropriate surfactant, and yielded vesicle size and percentage encapsulation efficiency of 1.3 mm and 98.9%, respectively. The developed system was characterised w.r.t. morphology, transition temperature, drug release, skin permeation and skin irritancy. Proniosomes exhibited a sustained release pattern of BCT in vitro. Skin permeation study revealed high penetration of proniosomes with sustained release of BCT through rat skin. The optimised proniosomal formulation showed enhanced transdermal flux of 16.15 mg/cm 2 /h as compared to 3.67 mg/cm 2 /h for drug dispersion. The developed formulations were observed as non-irritant to the rat skin and were found as quite stable at 4 and 25 C for 90 days w.r.t. vesicle size and drug content. The dried proniosomal formulation could act as a promising alternative to niosomes and preferably for transdermal delivery of BCT.

show abstract

Section: Optimisation Of the Proniosomal Formulationsmentioning

confidence: 99%

Section: Optimisation Of the Proniosomal Formulationsmentioning

confidence: 99%

Proniosomal gel-mediated transdermal delivery of bromocriptine:in vitroandex vivoevaluation

Lather¹,

Sharma²,

Pandita³

2016

Journal of Experimental Nanoscience

View full text Add to dashboard Cite

show abstract

“…In fact, the interaction between cholesterol and lecithin is a primary reaction in cell membranes, with the molar ratio of cholesterol to lecithin varying from 0.1 to 1 16. 17 It has also been suspected that lecithin may have beneficial effects on the properties of the cell membrane, such as permselectivity, fixed charge density, and fluidity characteristics 18. Our previous experiments have confirmed that lecithin does not significantly alter the surface tension, which suggests that the foamability of lecithin is much less than that of most surfactants 15.…”

Section: Introductionmentioning

confidence: 99%

Lecithin‐enhanced biotransformation of cholesterol to androsta‐1,4‐diene‐3,17‐dione and androsta‐4‐ene‐3,17‐dione

Wang

Huang

Rathman

et al. 2002

J of Chemical Tech & Biotech

View full text Add to dashboard Cite

A biotransformation process using Mycobacterium sp was studied for androsta-1, 4-diene-3,17-dione (ADD) and androsta-4-ene-3,17-dione (AD) production from cholesterol. Cholesterol has a poor solubility in water ($1.8 mg dm À3 at 25°C), which makes it difficult to use as the substrate for biotransformation. Lecithin is a mixture of phospholipids of phosphatidylcholine (PC) and phosphatidylethanolamine (PE), which behave like surfactants and can form planar bi-layer structures in an aqueous medium. Therefore, a small amount of lecithin (<1 g dm À3 ) can be used to form stable colloids with cholesterol at a relatively high concentration (20 g dm À3 ) in water. In this work, an energy density of 1000 J cm À3 from sonication was provided to overcome the self-association of cholesterol and to generate a stable lecithin-cholesterol suspension that could be used for enhanced biotransformation. The lecithin-cholesterol suspension was stable and could withstand typical autoclaving conditions (121°C, 15 psig, 20 min). In contrast to conventional surfactants, such as Tween 80, that are commonly used to help solubilize cholesterol, lecithin did not change the surface tension of the aqueous solution nor cause any significant foaming problem. Lecithin was also biocompatible and showed no adverse effect on cell growth. Compared with the medium with Tween 80 as the cholesterol-solubilizing agent, lecithin greatly improved the biotransformation process in regard to its final product yield ($59% w/w), productivity (0.127-0.346 g dm À3 day À1), ADD/AD ratio (6.7-8), as well as the long-term process stability. Cells can be reused in repeated batch fermentations for up to seven consecutive batches, but then lose their bioactivity due to aging problems, possibly caused by product inhibition and nutrient depletion.

show abstract

Surfactant stabilised colloidal cholesterol

et al. 1993

View full text Add to dashboard Cite

Dispersion of Cholesterol in Aqueous Surfactant Solutions: Interpretation of Viscosity Data

Cited by 4 publications

References 19 publications

Proniosomal gel-mediated transdermal delivery of bromocriptine:in vitroandex vivoevaluation

Proniosomal gel-mediated transdermal delivery of bromocriptine:in vitroandex vivoevaluation

Lecithin‐enhanced biotransformation of cholesterol to androsta‐1,4‐diene‐3,17‐dione and androsta‐4‐ene‐3,17‐dione

Surfactant stabilised colloidal cholesterol

Contact Info

Product

Resources

About