Factorial design for PEGylated nanoparticles bearing temozolomide The main effect of A, B, C and D represents the www.selleckchem.com/products/PD-0332991.html average result of changing variable at a time from its low level to high level. The interaction terms (AB, AC, AD, BC, BD, CD, A2, B2, C2 and D2) show how the PDE changes when 2 variables are simultaneously changed. The negative coefficient for all the independent variables (D, AC, BD, A2, C2 and D2) indicate unfavorable effect on the PDE while others are exhibiting positive interaction which indicate favorable effect on the PDE as its concentration in all selected formulation is kept unchanged. Among the four independent variables the lowest coefficient value is for D (-0.36 and p < 0.05) indicating that this variable is insignificant in the prediction of PDE.

It is also observed that the PDE does not significantly change (p < 0.05) because as on changing sonication time from 30 sec to 90 sec there is very little decrease in the PDE which shows very less amount of drug loss due to size reduction of the nanoparticles. Similarly, the effect of PVA on the PDE of various nanoparticles was observed and as on increasing the PVA concentration from 0.5 to 1% in nanoparticles the PDE increases significantly while on further increasing PVA concentration no significant change in PDE was observed in all the cases of nanoparticles formulations (Eqns. 1 and 3). This shows an appropriate concentration of PVA (surfactant 1%) for the better formation of emulsion.

The Variance Inflation Factor (VIF) measures how much the variance of that model coefficient is inflated by the lack of orthogonality in the design and calculated for Non-PEGylated and PEGylated formulations for temozolomide which is found to be near 1 indicating good estimation of the coefficient (Tables 3 and and4).4). Similarly Ri-squared is near to zero which is leading to good model. The model F value calculated in the range of 75.15 to 81.00 which implies the models are significant. The values of Prob > F less than 0.05 are indicating that model terms are significant. In all cases A, B, C, D, AB, A2 and B2 are significant model terms. The lack of fit values ��F-value�� for Non-PEGylated nanoparticles was found to be 61.86, which implies the lack of fit is not significant relative to the pure error and there are only 10�C11% chances of large lack of fit ��F-value�� which could occur due to noise and non-significant lack of fit ��F-value�� is good fit of model.

Similar results were obtained in PEGylated nanoparticles bearing temozolomide where lack of fit ��F-value�� was found to be 11.44% which is non-significant related to pure error. In both these cases 17�C23% chances of large lack of fit ��F-value�� could occur due to noise. In both cases ��Pred R-squared�� values are in reasonable GSK-3 agreement with the ��Adj R-squared�� values. The Adeq-Precision is the measures of the signal to noise ratio. A ratio > 4 is desirable.