Effect of PLGA MW, DTG loading and pre or post loading on the in vitro release kinetics of DTG. A) Release kinetics of DTG from PSIs fabricated with varying PLGA molecular weight (MW 11 kDa, 27 kDa, 54 kDa). DTG loading was held constant at ~570 mg/g in all PSIs. Error bars represent standard deviation of n = 3 samples. Statistical analysis: ANOVA with Tukey's multiple comparisons tests, *p < 0.05. B) Release kinetics of DTG from PSIs fabricated with various DTG loading (225, 450, 550, 650, and 850 mg/g). Error bars represent standard deviation of n = 3 samples. The ‘x’ in the graph represents the timepoint at which PSIs (DTG-225 and DTG-450) significantly swelled and changed in size. Statistical analysis: ANOVA with Tukey's multiple comparisons tests, **p < 0.01. C) Release kinetics of DTG from PSIs fabricated with varying compression forces (0.5, 1.0, 1.5 US.ton). DTG concentration was held constant at 650 mg/g. Error bars represent standard deviation of n = 3 samples. D) Release kinetics of DTG from PSIs fabricated by pre-loading method and post-loading method. DTG concentration was held constant at 650 mg/g. Error bars represent standard deviation of n = 3 samples. E) Summary of release kinetics including initial burst release and zero-order release rate for PSIs described in A-D.