2.2.2. Nano Co-Crystal Optimization

A CCD design generated using version 11 Design Expert® software (Stat-Ease Inc., Minneapolis, MN, USA) was selected for the optimization of process variables for the synthesis of NCC using reduced-temperature sonoprecipitation. Preliminary studies revealed that two independent factors viz., SDS and TPGS 1000 concentration were critical [25]. The PS, PDI and ZP were monitored. The experiments conducted for the CCD are listed in Table 1. All experiments were performed in triplicate for each run using the levels suggested by the CCD, which also includes repeated runs at specific levels. Furthermore, the runs are conducted in a randomised manner to minimize any potential bias.


**Table 1.** Summary of CCD experiments for nano co-crystals (NCC) optimization.

Sodium dodecyl sulphate (SDS), α-tocopheryl polyethylene glycol succinate (TPGS 1000).
