In the present paper, the physicochemical incompatibility of doxepin with dextrose was evaluated in solid-state mixtures. The compatibility was evaluated using different physicochemical methods such as differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy and mass spectrometry. Non-isothermally stressed physical mixtures were used to study the solidstate kinetic parameters. Different thermal models such as Friedman, Flynn-Wall-Ozawa and Kissinger-AkahiraSunose were used for the characterization of the drugexcipient mixtures. Overall, the incompatibility of doxepin as a tertiary amine with dextrose as a reducing carbohydrate was successfully assessed. DSC-based kinetic analysis is a simple and fast method in evaluation of different drug-excipient mixtures incompatibility. Finally, it can be recommended to exclude dextrose from doxepin pharmaceutical formulations and also to apply the easy and versatile DSC method in kinetic study of drug-excipient incompatibility.

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Purpose: In the present study the incompatibility of FLM (fluvoxamine) with lactose in solid state mixtures was investigated. The compatibility was evaluated using different physicochemical methods such as differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR) spectroscopy and mass spectrometry. Methods: Non-Isothermally stressed physical mixtures were used to calculate the solid–state kinetic parameters. Different thermal models such as Friedman, Flynn–Wall–Ozawa (FWO) and Kissinger–Akahira–Sunose (KAS) were used for the characterization of the drug-excipient interaction. Results: Overall, the incompatibility of FLM with lactose as a reducing carbohydrate was successfully evaluated and the activation energy of this interaction was calculated. Conclusion: In this research the lactose and FLM Maillard interaction was proved using physicochemical techniques including DSC and FTIR. It was shown that DSC- based kinetic analysis provides fast and versatile kinetic comparison of Arrhenius activation energies for different pharmaceutical samples.

In the present study the physicochemical stability of sertraline with lactose was evaluated in drug-excipient binary mixtures. Different physicochemical methods such as differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy, and mass spectrometry were applied to confirm the incompatibility. The final aim of this study was to evaluate the kinetic parameters using a fast and sensitive DSC method. Solid-state kinetic parameters were derived from nonisothermally stressed physical mixtures using different thermal models such as Friedman, Flynn-Wall-Ozawa, and Kissinger-Akahira-Sunose. Overall, the instability of sertraline with lactose was successfully evaluated. Further confirmation was made by tracking the Maillard reaction product of sertraline and lactose by mass spectrometry. DSC scans provided important information about the stability of sertraline in solid-state condition and also revealed the related thermokinetic parameters in order to understand the nature of the chemical instability.