Co-amorphous Of Etoricoxib And Citric Acid With Enhancement in Solubility And Dissolution

Etoricoxib is a non-steroidal anti-inflammatory drug (NSAID), included to class II of Biopharmaceutical Classification System (BCS) with low solubility in water and high permeability. This research aims to increase the solubility and dissolution of etoricoxib by preparing into co-amorphous phase using citric acid as the coformer at mol ratio of 1:1 by Liquid Assisted Grinding (LAG) method. Co-amorphous characterization were carried out by several solid state characterizations, which are Differential Scanning Calorimetry (DSC) analysis, Powder X-ray Diffraction (PXRD) analysis, Fourier Transform Infrared (FTIR) spectroscopy, and Scanning Electron Microscopy (SEM) analysis. To confirm the amount of co-amorph dissolved, the solubility test was carried out in distilled water for 24 hours using an orbital shaker and the dissolution test was done in phosphate-buffered medium for 45 minutes. Then, the quantity of etoricoxib was analysed by High Performance Liquid Chromatography (HPLC) using phosphate-buffered saline pH 3.5 and acetonitrile with a ratio of 55:45 as mobile phase. The characterization results showed a decrease in the melting point of co-amorphous in the DSC thermogram, and a decline in the intensity of the diffraction peaks in the PXRD diffractogram. FTIR spectrum showed no functional groups formed which confirmed by the wave-numbers of co-amourphous closed to those of the intact components. The morphology of co-amourphous depicted the irregular shape and pores which confirmed by SEM analysis. The solubility results in the co-amorphous showed an increase of 1.592 times and the dissolution efficiency results for 45 minutes showed an increase of 1.153 times compared to intact etoricoxib, respectively. In summary, the formation of co-amorphous etoricoxib - citric acid can enhance the solubility and dissolution of etoricoxib.