2.4.1. Physical robustness to dilution
SNPDs were exposed to different folds of dilutions (100,
500 and 1000) with different media (water, 0.1N HCl and
phosphate buffer pH 7.4). Diluted formulations were stored on
shelf for 6 h where any physical changes were monitored.
Percentage of transmission was measured by using spectrophotometer
(Shimadzu, Japan) at wavelength 638.3 nm (Elnaggar et al.,
2009; Elsheikh et al., 2012; Gupta et al., 2011)