Viscoelastic evaluation of topical creams containing microcrystalline cellulose/sodium carboxymethyl cellulose as stabilizer

Abstract

The purpose of this study was to examine the viscoelastic properties of topical creams containing various concentrations of microcrystalline cellulose and sodium carboxymethyl cellulose (Avicel(R) CL-611) as a stabilizer. Avicel CL-611 was used at 4 different levels (1%, 2%, 4%, and 6% dispersion) to prepare topical creams, and hydrocortisone acetate was used as a model drug. The viscoelastic properties such as loss modulus (G"), storage modulus (G'), and loss tangent (tan delta) of these creams were measured using a TA Instruments AR 1000 Rheometer and compared to a commercially available formulation. Continuous flow test to determine the yield stress and thixotropic behavior, and dynamic mechanical tests for determining the linear viscosity time sweep data, were performed. Drug release from the various formulations was studied using an Enhancer TM Cell assembly. Formulations containing 1% and 2% Avicel CL-611 had relative viscosity, yield stress, and thixotropic values that were similar to those of the commercial formulation. The elastic modulus (G') of the 1% and 2% formulation was relatively high and did not cross the loss modulus (G"), indicating that the gels were strong. In the commercial formulation, G' increased after preshearing and broke down after 600 seconds. The strain sweep tests showed that for all formulations containing Avicel CL-611, the G' was above G" with a good distance between them. The gel strength and the predominance of G' can be ranked 6% > 4% > 2%. The strain profiles for the 1% and 2% formulations were similar to those of the commercial formulation. The delta values for the 1% and 2% formulations were similar, and the formulations containing 4% Avicel CL-611 had lower delta values, indicating greater elasticity. Drug release from the commercial preparation was fastest compared to the formulations prepared using Avicel CL-611, a correlation with the viscoelastic properties. It was found that viscoelastic data, especially the strain sweep profiles of products containing Avicel CL-611 1% and 2%, correlated with the commercial formulation. Rheological tests that measure the viscosity, yield stress, thixotropic behavior, other oscillatory parameters such as G' and G" are necessary tools in predicting performance of semisolids.

Improved and Safe Transcorneal Delivery of Flurbiprofen by NLC and NLC-Based Hydrogels

“…The magnitude of yield stress relates to the strength of the three-dimensional network microstructure. 42 Semisolid suspensions with a constant solid volume fraction may differ in its viscosities and yield values due to the particle size and size distribution (PI) differences. The larger the particles are, the lower the viscosity is.…”

Cellulose nanofibrils for one-step stabilization of multiple emulsions (W/O/W) based on soybean oil

“…and foods (ice creams, pastes, etc.) [10]. Microcrystalline cellulose is prepared via acid treatment of wood fibers, which dissolves the amorphous regions yielding crystalline particles of low aspect ratio and with sizes in the order of tens of micrometers [11,12].…”

Biodegradable Materials for Multilayer Transient Printed Circuit Boards

“…Both Na-CMC and PEO are water soluble [ 23,24 ] and biocompatible [ 25,26 ] ; each has been used in food, pharmaceuticals, and cosmetics as stabilizers for emulsions [ 27,28 ] and thickeners. [ 29,30 ] As cast, the Na-CMC fi lms have a surface roughness of Figure S3a).…”