Fabrication of ATR Nanocrystals Using Chitosan

Nanocrystals were prepared by combination of anti-solvent precipitation process followed by probe sonication method.31 (link) Briefly, organic feeds were prepared by dissolving 80 mg of ATR and Labrasol^® (0.5% w/w) in methanol. Then the organic feeds were injected instanta neously into polymer solution containing chitosan and were pre-homogenized at 12,000 rpm for 2 minutes (Ultra-turrax T-25 1KA, Germany). The dispersion was further processed for particle size reduction using probe sonication (Sonics Vibra cell, VCX 750; Sonics & Materials, Inc., Newtown, CT, USA) at 20–23 kHz for 4 minutes to prepare 1% w/w ATR nanocrystals. The process was established and repeated to fabricate ATR nanocrystals using Labrasol^® alone and in combination with three different molecular weight chitosan (CS_L, CS_M, CS_H). Further, the final colloidal dispersions of all batches were lyophilized (Christ alpha 1-2-LD plus, Germany) to obtain powder chitosan based ATR nanocrystals.