Adeyeye Moji Christianah, Jain Ashwinkumar C, Ghorab Mohamed K M, Reilly William J
Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA 15282, USA.
AAPS PharmSciTech. 2002;3(2):E8. doi: 10.1208/pt030208.
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.
本研究的目的是考察含有不同浓度微晶纤维素和羧甲基纤维素钠（Avicel® CL - 611）作为稳定剂的外用乳膏的粘弹性特性。以4种不同水平（1%、2%、4%和6%分散体）使用Avicel CL - 611制备外用乳膏，并使用醋酸氢化可的松作为模型药物。使用TA仪器AR 1000流变仪测量这些乳膏的粘弹性特性，如损耗模量（G"）、储能模量（G'）和损耗角正切（tan δ），并与市售制剂进行比较。进行了用于确定屈服应力和触变性行为的连续流动试验，以及用于确定线性粘度时间扫描数据的动态力学试验。使用Enhancer TM细胞组件研究了各种制剂的药物释放情况。含有1%和2% Avicel CL - 611的制剂的相对粘度、屈服应力和触变性值与市售制剂相似。1%和2%制剂的弹性模量（G'）相对较高，且未超过损耗模量（G"），表明凝胶强度较高。在市售制剂中，预剪切后G'增加，600秒后分解。应变扫描试验表明，对于所有含有Avicel CL - 611的制剂，G'高于G"，且两者之间有良好的差距。凝胶强度和G'的优势程度可排序为6% > 4% > 2%。1%和2%制剂的应变曲线与市售制剂相似。1%和2%制剂的δ值相似，含有4% Avicel CL - 611的制剂的δ值较低，表明弹性更大。与使用Avicel CL - 611制备的制剂相比，市售制剂的药物释放最快，这与粘弹性特性相关。研究发现，粘弹性数据，尤其是含有1%和2% Avicel CL - 611的产品的应变扫描曲线，与市售制剂相关。测量粘度、屈服应力、触变性行为以及其他振荡参数（如G'和G"）的流变学试验是预测半固体性能的必要工具。
