Table 2.

Physicochemical parameters of the ACY-AqS and PLGA-TPGS-NPs determined at 25 °C (A); and corneal permeation parameters of ACY from the two formulations (B); (values were expressed in mean ± SD, n = 3).

(A) Physicochemical parameters
Parameters	Time points	ACY-AqS	PLGA-TPGS-NPs
Clarity	Initially	Clear	Clear
	After 30 days	Clear	Clear
pH	Initially	6.78 ± 0.27	6.88 ± 0.23
	After 30 days	6.89 ± 0.25	7.21 ± 0.12
Refractive index	Initially	1.332 ± 0.009	1.353 ± 0.008
	After 30 days	1.345 ± 0.007	1.367 ± 0.003
Surface tension	Initially	39.53 ± 1.02	41.28 ± 1.04
(mN·m−1)	After 30 days	42.27 ± 1.04	45.13 ± 1.03
Viscosity (mPa·s)	Initially	30.15 ± 1.07	35.42 ± 1.85
	After 30 days	33.27 ± 1.94	39.35 ± 2.05

(B) Corneal permeation parameters
	Parameters	PLGA-TPGS-NPs	ACY-AqS
		(0.28%, w/v of ACY)	(0.28%, w/v of ACY)
	Cumulative amount permeated (µg cm−2 at 6 h)	1872.691 ± 42.582	1933.109 ± 12.895
	pH	7.01 ± 0.09	7.24 ± 0.15
	Steady-state flux, J (µg cm−2 h−1)	521.541 ± 21.731	365.765 ± 13.861
	Permeability coefficient, P (cm h−1)	(18.627 ± 0.0077) × 10−2	(13.063 ± 0.0049) × 10−2