PHARMACEUTICAL STUDIES ON THE EFFECT OF DIFFERENT POLOXAMERS ON THE DISOLUTION RATE OF BSC CLASS II ANTIGOUT MODEL DRUG (FEBUXOSTAT)
Ahmed A. El Shenawy*, Wael A. Abdelhafez, Ahmed Ismail, Alaa A. Kassem
ABSTRACT
The aim of the present work was to increase the dissolution rate of febuxostat (FXT) (Xanthine oxidase enzyme inhibitor), a practically water-insoluble drug using solid dispersion with hydrophilic polymers. Two commercially available poloxamer grades (poloxamer 188 and poloxamer407) were selected, and solid dispersions containing different weight ratio of poloxamers and FXT were prepared by kneading method. The kneading method was used to prepare FXT/ poloxamer solid dispersions due to the good results obtained in previous researches reported by many researchers. FXT has low, variable oral bioavailability and poor water solubility with slow dissolution and peripheral degradation. The prepared solid dispersions was characterized by drug content, in vitro release study, Fourier Transform Infra-Red (FT-IR), Scanning electron microscopy (SEM) and Differential scanning calorimetry (DSC). The results revealed that FXT solid dispersion using poloxamer 188 and poloxamer 407 increased the dissolution rate in comparison to unprocessed FXT. Further, the thermal analysis showed that the FXT enhanced dissolution was due to FXT crystal pattern changes. Moreover, the results revealed that, FXT dissolution rate was inversely proportional with poloxamer ratio as its increase, drug dissolution decreased. SEM image revealed that the solid dispersion granules did not have a perfect spherical shape and a rugged surface. It could be concluded that, solid dispersion technique was a powerful method that enhanced the dissolution rate of FXT utilizing kneading method and poloxamer 188 in 1:1 drug/ polymer w/w ratio was effectively enhanced the dissolution rate of FXT more than poloxamer 407.
Keywords: Febuxostat, Solid dispersions, Poloxamer.
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