Die Pharmazie is published by IMR Press from Volume 81 Issue 1 (2026). Previous articles were published by another publisher under the CC-BY licence, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement.
Preparation and characterization of freeze-dried 2-methoxyestradiol nanoparticle powders
Bin Du 1, Xiao-Tian Li 1, Ya Zhao 1, You-Mei A 1, Zhen-Zhong Zhang 2
Affiliations
Article Info
1 School of Pharmacy, Zhengzhou University, Zhengzhou, P.R. China
2 School of Pharmacy, Zhengzhou University, 100 Science Road, Zhengzhou, 450001, P.R. China, Email: zzupaper@sina.com
Abstract
Poorly water–soluble compounds are difficult to develop as drug products using conventional formulation techniques and are frequently abandoned early in discovery. In the present study, a nanoprecipitation–high–frequency ultrasonication technique was adapted to produce drug nanosuspensions. The formulation of 2–methoxyestradiol (2–ME) as nanosuspension, either in the form of lyophilized powder or granules, was very successful in enhancing dissolution rate, more 45 times than bulk 2–ME being dissolved in the first 10 min. The increase in vitro dissolution rate may favourably affect bioavailability. The nanosuspension produced was then characterized using particle size determination, zeta potential measurement, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and X–ray analysis. Results showed that freeze–dried nanosuspension composed of amorphous particles with a mean particle size of 244 ± 10.6 nm (polydispersity index of 0.21 ± 0.02) was obtained. Physical stability studies showed that 2–ME nanosuspension remained homogeneous with slight increase in mean particle size and polydispersity index over a 3–month period.
