Table 1.

Mean size, polydispersity index (PDI), zeta potential, and encapsulation efficiency of solid lipid nanoparticles containing diclofenac after preparation and two-month storage at 2–8°C (mMean ± SD, n = 3).

	After preparation	After one month	After two months
Mean size (nm)	172.7 ± 6.3	216.4 ± 10.2	269.5 ± 2.8
PDI	0.254 ± 0.001	0.184 ± 0.044	0.150 ± 0.083
Zeta potential (mV)	−0.9 ± 2.0	−1.5 ± 0.5	0.5 ± 1.3
Encapsulation efficiency (%)	95.1 ± 4.2	98.2 ± 0.8	98.0 ± 2.4