Thermoanalytical, Spectroscopic and Chromatographic Approach to Physicochemical Compatibility Investigation of 5-Aminosalicylates and Folic Acid

Fixed-dose combinations have shown to be a great alternative to traditional polytherapy; however, development of such formulation requires thorough physicochemical compatibility investigation of active pharmaceutical ingredients to provide a stable, safe and therapeutically effective product. In this work, differential scanning calorimetry, X-ray powder diffraction, isothermal stress testing followed by Fourier-transform infrared spectroscopy and chromatographic analysis as well as dissolution studies were used for physicochemical compatibility investigation of folic acid and balsalazide or olsalazine. Balsalazide and olsalazine as well as their blend were successfully characterised regarding their physicochemical properties using the mentioned techniques. Differential scanning calorimetry gave ambiguous results due to premature degradation of balsalazide. On the contrary, other techniques have implied the absence of any chemical reactions or physical changes in prepared blends. Obtained result imply that folic acid is compatible with both balsalazide and olsalazine which goes in favour of developing proposed fixed-dose combinations. This work is licensed under a Creative Commons Attribution 4.0 International License