Analytical Considerations for Measuring the Globule Size Distribution of Cyclosporine Ophthalmic Emulsions

Publication date: Available online 17 August 2018Source: International Journal of PharmaceuticsAuthor(s): Peter Petrochenko, Naresh Pavurala, Yong Wu, Sook Yee Wong, Hamideh Parhiz, Kang Chen, Sharadrao M. Patil, Haiou Qu, Patrick Buoniconti, Absar Muhammad, Stephanie Choi, Darby Kozak, Muhammad Ashraf, Celia N. Cruz, Jiwen Zheng, Xiaoming XuAbstractMeasurement of particle size and size distribution of complex drug products exhibiting complex rheological behaviors can be challenging as these properties may be beyond the theoretical assumptions of the measurement technique. Herein cyclosporine (CsA) ophthalmic emulsion was selected as a model complex system, and an in-depth assessment of particle size was performed using five fundamentally different particle sizing techniques, including dynamic light scattering (DLS), laser diffraction (LD), nanoparticle tracking analysis (NTA), cryogenic transmission electron microscopy (Cryo-TEM) and 2-dimensional diffusion ordered spectroscopy nuclear magnetic resonance (2D DOSY-NMR). The effect of various viscosity modifying and stabilizing excipients in the emulsions was assessed using four types of CsA formulations, i.e., 1) no viscosity modifying excipients, 2) carbomer copolymer type A (CCA), 3) Carbopol 1342, or 4) hydroxypropyl methyl cellulose (HMPC). In general, the variability of reported particle size increased, and is not as accurate, for emulsions dispersed in a non-Newtonian fluid and at higher emulsion concentrations. This ef...
Source: International Journal of Pharmaceutics - Category: Drugs & Pharmacology Source Type: research