Modulation of the Photophysical Properties of Curcumin in Nonionic Surfactant (Tween-20) Forming Micelles and Niosomes: A Comparative Study of Different Microenvironments

Abstract

The modulation of the photophysical properties of curcumin inside two different types of microenvironments provided by nonionic surfactant forming micelles and vesicles (niosomes) has been investigated using steady state and time-resolved fluorescence spectroscopy. The formation of small unilamellar Tween-20/cholesterol niosomes with narrow size distribution has been successfully demonstrated by means of dynamic light scattering (DLS) and transmission electron microscopy (TEM) techniques. Our results indicate that niosomes are a better possible delivery system than the conventional surfactants forming normal micelles to suppress the level of degradation of curcumin. The enhanced fluorescence intensity along with the significant blue-shift in the emission maxima of curcumin upon encapsulation into the hydrophobic microenvironments of micelles and niosomes is a consequence of the reduced interaction of curcumin with the water molecules. We found that the more rigid and confined microenvironment of niosomes enhances the steady state fluorescence intensity along with the fluorescence lifetime of curcumin more than in micelles. The rigidity of the niosome membrane which arises basically due to the presence of cholesterol molecules increases the level of interaction between curcumin and the oxoethylene units of Tween-20 molecules. It is also possible for the hydroxyl groups of the cholesterol moieties to form intermolecular hydrogen bonds with curcumin to perturb nonradiative deactivation mechanism through excited state intramolecular hydrogen atom transfer (ESIHT).

Exploiting Co‐solubilization of Warfarin, Curcumin, and Rhodamine B for Modulation of Energy Transfer: A Micelle FRET On/Off Switch

“…This promotes electrostatic attraction between anionic WF and cationic CTAB micelles. To estimate the interaction of WF with CTAB micelles, the binding constant K , calculated according to a method already described, was found to be 5.55×10 5 m −1 . The large binding constant indicates favorable interaction between WF and CTAB micelles.…”

Topical Niosome Gel of Zingiber cassumunar Roxb. Extract for Anti-inflammatory Activity Enhanced Skin Permeation and Stability of Compound D

“…E a of compound D were, thus, estimated to be 28.6 and 27.3 kJ/mol for ZC gel and its niosomal gel, respectively. Arrhenius plots of curcumin in niosomes were also similarly parallel and comparable to solubilized form with an E a of about 10 kJ/mol (32). Also, intermolecular interactions between curcumin and cholesterol in the niosomal bilayer reduce thermal interference to the encapsulated curcumin.…”

Size and Stability of Curcumin Niosomes from Combinations of Tween 80 and Span 80

“…Niosomes were prepared by thin-film hydration method as reported in the literature (Mandal et al 2013) with some modifications. Initially, non-ionic surfactants and cholesterol (molar ratio = 2:1) and 0.04 g curcumin were dissolved in mixture of chloroform and methanol (3:1 v/v) in a round bottomed flask.…”

“…The two major components used for the preparation of niosomes are cholesterol and non-ionic surfactant. Niosomes prepared with non-ionic surfactant, Tween 20 in combination with cholesterol was reported to suppress the degradation of curcumin better than micelles (Mandal et al 2013). Tween 80 and Span 80 have been tested in pharmaceutical field as drug delivery system and in particular they can be used to prepare highly stable niosomes (Ruckmani et al 2000;Yoshioka et al 1994).…”