Table 8. Release kinetics of drug at different pH from microspheres.

Formulation	pH	Zero order release kinetics		First order release kinetics		Higuchi model
		K0 (h−1)	r	K1 (h−1)	r	K2 (h−1)	r
F1	1.2	4.749	0.752	0.165	0.873	0.219	0.890
	7.4	2.565	0.959	0.045	0.972	0.133	0.994
F2	1.2	4.537	0.749	0.131	0.841	0.209	0.886
	7.4	2.590	0.952	0.038	0.951	0.127	0.988
F3	1.2	4.057	0.903	0.100	0.971	0.178	0.970
	7.4	2.601	0.944	0.038	0.954	0.128	0.990
F4	1.2	4.375	0.865	0.110	0.956	0.195	0.961
	7.4	2.551	0.882	0.037	0.908	0.055	0.964
F5	1.2	4.275	0.851	0.100	0.941	0.192	0.954
	7.4	2.726	0.853	0.039	0.866	0.131	0.937
F6	1.2	4.671	0.923	0.097	0.986	0.204	0.939
	7.4	2.807	0.848	0.042	0.874	0.137	0.986
F7	1.2	4.801	0.942	0.089	0.990	0.209	0.993
	7.4	2.921	0.910	0.045	0.927	0.142	0.973