Table 5
Nonlinear fits of β-E release from elemene injection and PEGylated liposomes
| Equation type | Elemene injection | PEG-Lipo-β-E | ||
|---|---|---|---|---|
| Equation | R2 | Equation | R2 | |
| Zero-order model, F = K0 * t | F = 3.150 * t | 0.3520 | F = 2.289 * t | 0.6869 |
| First-order model, F = 100 * (1 – e−k1*t) | F = 100 * (1 – e−0.101*t) | 0.9375 | F = 100 * (1 – e−0.042*t) | 0.9301 |
| Higuchi model, F = KH * t0.5 | F = 16.839 * t0.5 | 0.8838 | F = 11.913 * t0.5 | 0.9836 |
| Weibull model, | 0.9511 | 0.9909 | ||
F, the fraction (%) of drug released in time t; K0, K1 and KH, the zero-order, first-order, and Higuchi release constant, respectively; α, the scale parameter which defines the time scale of the process; β, the shape parameter which characterizes the curve as either exponential (β = 1; case 1), sigmoid, S-shaped, with upward curvature followed by a turning point (β > 1; case 2), or parabolic, with a higher initial slope and after that consistent with the exponential (β < 1; case 3).