Fig. 4From: Improving the anticancer effect of afatinib and microRNA by using lipid polymeric nanoparticles conjugated with dual pH-responsive and targeting peptidesStability of afatinib in LPN-HR at 4 °C. a Size and zeta potential; b PDI of Afa/LPN-HR at 4 °C for 28 days. Afa/LPN-HR was stored at 4 °C for 28 days and the size, zeta potential and PDI was measured by Zetasizer. The values are the mean ± standard error (SD). For each group, n = 3Back to article page