Dabbaghi Maryam, Namjoshi Sarika, Panchal Bhavesh, Grice Jeffrey E, Prakash Sangeeta, Roberts Michael Stephen, Mohammed Yousuf
Therapeutics Research Group, The University of Queensland Diamantina Institute, Faculty of Medicine, University of Queensland, Brisbane, QLD 4102, Australia.
School of Agriculture and Food Sciences, The University of Queensland, Brisbane, QLD 4072, Australia.
Pharmaceutics. 2021 Aug 27;13(9):1351. doi: 10.3390/pharmaceutics13091351.
Rheological characteristics and shear response have potential implication in defining the pharmaceutical equivalence, therapeutic equivalence, and perceptive equivalence of commercial topical products. Three creams (C1 and C3 as oil-in-water and C2 as water-in-oil emulsions), and two gels (G1 and G2 carbomer-based) were characterized using the dynamic range of controlled shear in steady-state flow and oscillatory modes. All products, other than C3, met the Critical Quality Attribute criteria for high zero-shear viscosity () of 2.6 × 10 to 1.5 × 10 Pa∙s and yield stress () of 55 to 277 Pa. C3 exhibited a smaller linear viscoelastic region and lower (2547 Pa∙s) and (2 Pa), consistent with lotion-like behavior. All dose forms showed viscoelastic solid behavior having a storage modulus (G') higher than the loss modulus (G″) in the linear viscoelastic region. However, the transition of G' > G″ to G″ > G' during the continual strain increment was more rapid for the creams, elucidating a relatively brittle deformation, whereas these transitions in gels were more prolonged, consistent with a gradual disentanglement of the polymer network. In conclusion, these analyses not only ensure quality and stability, but also enable the microstructure to be characterized as being flexible (gels) or inelastic (creams).
流变学特性和剪切响应对于界定市售局部用产品的药学等效性、治疗等效性和感知等效性具有潜在意义。使用稳态流动和振荡模式下的可控剪切动态范围对三种乳膏（C1和C3为水包油型，C2为油包水型乳剂）和两种凝胶（G1和G2为基于卡波姆的凝胶）进行了表征。除C3外，所有产品均符合关键质量属性标准，即高零剪切粘度（）为2.6×10至1.5×10 Pa∙s，屈服应力（）为55至277 Pa。C3表现出较小的线性粘弹性区域以及较低的（2547 Pa∙s）和（2 Pa），这与洗剂样行为一致。所有剂型在线性粘弹性区域均表现出粘弹性固体行为，其储能模量（G'）高于损耗模量（G″）。然而，在持续应变增加过程中，乳膏从G' > G″转变为G″ > G'的速度更快，这表明其变形相对较脆，而凝胶中的这些转变更为持久，这与聚合物网络的逐渐解缠一致。总之，这些分析不仅确保了质量和稳定性，还能够将微观结构表征为柔性（凝胶）或非弹性（乳膏）。
