Table 1.

Kinetic study for CS permeation from the eye drops (CS 20.2 mg/mL, HA 0.4%) through a hydrophilic membrane made of regenerated cellulose (Visking^®).

Kinetic Model	Equation	Kinetic Parameter	-r
Zero-order	$\left(Q_{\infty }-Q_t\right)=Q_{\infty }-Q_0)-k ·t$	k = (4.50 ± 0.53)·10−2, mg·min−1	0.9949
First-order	$ln\left(Q_{\infty }-Q_t\right)=ln\left(Q_{\infty }-Q_0\right)-k ·t$	k = (5.22 ± 1.09)·10−3, min−1	0.9840
Higuchi	$Q_t=k_H ·t^{1/2}$	KH = (9.42 ± 1.98)·10−1, min−1/2	0.9837
Korsmeyer–Peppas	$\frac{M_t}{M_{\infty }}=k_r ·t^n$	kr = (8.40 ± 0.43)·10−3, min−n, n = 0.80	0.9869

Note: Q₀, Q_t, Q_∞—CS content at time t₀, t, and t_∞, respectively, in mg; M_t/M_∞—CS fraction at time t and t_∞, respectively; t—time, in min; k, K_H, and k_r—permeation rate constants.