Table 1.
Levels of independent and dependent variables in design of experiment.
Table 2.
Effect of formulation components and process variables on different characteristics of microspheres.
Fig 1.
3 dimensional response surface graphs indicating (A) the effect of the concentration of polymer and stirring speed on particle size, and (B) the effect of the surfactant (PVA) concentration and stirring speed on particle size.
Fig 2.
3-dimensional response surface graphs indicating (A) the effect of the concentration of polymer and stirring speed on EE, and (B) the effect of the surfactant (PVA) and polymer concentration on EE.
Fig 3.
Drug release profiles of the microspheres prepared with (A) 50 mg of ethyl cellulose, (B) with 100 mg of ethyl cellulose, (C) with 150 mg of ethyl cellulose, and (D) of the all formulations.
Fig 4.
3-dimensional response surface graphs indicating (A) the effect of the concentration of polymer and stirring speed on dissolution rate, and (B) the effect of the surfactant (PVA) concentration and stirring speed on dissolution rate.
Table 3.
Predicted and actual values of independent and dependent variables for the optimized formulation.
Fig 5.
SEM analysis of Formulation P3 (A), Formulation P5 (B) and Formulation P10 (C) at different magnifications.
Table 4.
Values of correlation co-efficient of different kinetics models on release data.
Fig 6.
FTIR spectra of Pentazocine (a), Physical mixture (b), and optimized microsphere formulation (c).
Fig 7.
Thermogravimetric analysis of Pentazocine (a), Physical mixture (b), and optimized microsphere formulation (c).
Fig 8.
Powder x-ray diffractograms of Pentazocine (a), Physical mixture (b), and optimized microsphere formulation (c).