Physical–chemical characterization studies of ketoprofen for orodispersible tablets

The development of orodispersible tablets containing ketoprofen (KTP) offers versatility in administration to patients with swallowing difficulties. The rational development of a medication requires characterization studies for the solid state of the active ingredient and compatibility with excipients to thus ensure a high-quality, safe and effective pharmaceutical form. Therefore, compatibility studies were performed by differential scanning calorimetry (DSC) and thermogravimetry/derivative thermogravimetry (TG/DTG), spectroscopy techniques (DRIFT, DRX, Raman), and morphological analysis by scanning electron microscopy in order to obtain thermal characterization of the drug. The DSC curve demonstrated an endothermic, symmetrical and evident fusion event ( T peak = 96.37 °C, Δ H = −120.92 J g −1 ) and the TG/DTG curve showed mass loss of Δ m = 92.45% relative decomposition. For stability analysis, the non-isothermal kinetic study was carried out. The granulate KTP showed higher Ea = 77.30 ± 0.25 kJ mol −1 , hence being more stable than pure KTP (Ea = 54.69 ± 1.53 kJ mol −1 ). Regarding the compatibility study, a displacement of the drug’s melting point to lower temperatures was observed. However, a more significant interaction was evident with magnesium stearate. Further studies were performed using spectroscopic techniques of DRIFT, Raman, X-ray diffraction and by scanning electron microscopy, which demonstrated that there was no change in physicochemical properties of pure KTP. Therefore, through this study it is possible to produce orodispersible tablets by compression and freeze-drying methods containing ketoprofen.