Formulation and Optimization of Sustained Release Stavudine Microspheres Using Response Surface Methodology

Table 3

Analysis of variance (ANOVA) for all three responses^(a).

	Entrapment efficiency (%) (𝑌1)		Particle size (μm) (𝑌2)		𝑡80% release (min) (𝑌3)
Source	F	𝑃 value	F	𝑃 value	F	𝑃 value
Model	3.81	.0801	1.08	.4838	169.68	.0001
X1	1.60	.2617	0.11	.7556	326.82	.0001
X2	1.82	.2349	0.70	.4419	1.15	.3325
X1X2	0.21	.6682	3.33	.1277	13.97	.0135
X12	0.014	.9103	0.61	.4685	263.25	.0001
X22	1.21	.3209	0.53	.5011	0.77	.4199
X12X2	0.30	.6061	0.19	.6826	8.83	.0311
X1X22	2.51	.1738	0.90	.3857	3.18	.1348

^(a)Significant effect (𝑃 value <.5) of factors on individual responses are shown in bold; 𝑡_80% release: time of 80 percent of drug release; 𝑋₁: drug-to-polymer ratio; 𝑋₂: stirring speed.