Screening of solvents for based formulation (B) and non-ionic polymers for non-ionic polymer formulations (PF). The based formulations (B1–B6) were prepared with DW, PBS (pH7.4), BG, DPG, PG, and PEG 400 (a). Non-ionic polymer formulations (PF1-10) were prepared with polymers (including P188®, P407®, PEG 6000, IR®, K12®, PVP/VA S-630, TPGS, HS 15®, Soluplus®)(b). The permeation study was performed with Strat-M® membrane through the Franz diffusion cell system at 32 ± 1 °C for 24 h. Data are expressed as mean ± standard deviation (sd, n = 3).