Table 6.

Model parameters and R-squared values obtained from the fitting of the ketoprofen-impregnated PLA filament samples to the different mathematical models.

		Impregnating Conditions
		55 °C, 400 bar	75 °C, 250 bar	75 °C, 200 bar	55 °C, 250 bar
Zero-order	$R^2$	0.8780	0.9936	0.9824	0.9452
	$k_O$	0.0459	0.0287	0.0282	0.0149
First-order	$R^2$	0.8162	0.8484	0.8668	0.9536
	$k_1$	0.0735	0.1022	0.0919	0.0551
Higuchi	$R^2$	0.9747	0.9002	0.8781	0.7775
	$k_H$	0.2207	0.1640	0.1610	0.1089
Korsmeyer–Peppas	$R^2$	0.9625	0.9757	0.9737	0.8012
	$k_{KP}$	0.3786	0.0591	0.0737	0.0449
	$n$	0.3224	0.6219	0.5367	0.5571
Peppas–Sahlin	$R^2$	0.5533	0.8818	0.7674	0.4846
	$k_d$	0.4571	0.0123	0.0317	0.0158
	$k_r$	−0.0587	0.0337	0.0282	0.0147