The use of kinetic N-order model in description of active substance release from various drug forms. Part 2. Analysis of paracetamol and sodium diclofenac release from methylcellulose.

The first part of the monograph presented the premises and equations which are the basis for the proposed mathematical n-order model. This non-linear physical model obeying the laws of chemical kinetics was used to describe the processes of active substance release from drug form. The possibilities of its application in the mathematical description and detailed analysis of the kinetics of paracetamol and sodium diclofenac release from various viscosity gels based on methylcellulose were investigated. Moreover, the effect of temperature on the release profiles of the above-mentioned active substances from investigated formulations was analyzed. On the basis of a series of performed experiments and detailed comparative statistical analysis of the estimators of two parameters characterizing n-order model: release rate constant K and order coefficient of the release process N, it was demonstrated that the active substance release rate from formulations with uncontrolled release is correlated with actual order of the process. Also, the proposed n-order model was compared with models obeying the laws of chemical kinetics: 0-order model, 1-order model and with diffusion Higuchi "square root of time" model, and the comparison demonstrated superiority of the n-order model over standard models. A non-linear statistical analysis was performed by means of computer software Statistica Pl. v. 7.1 manufactured by StatSoft Polska and Mathematica v. 5.0 manufactured by Wolfram Research.