Impact of surfactants on the crystal growth of amorphous celecoxib

The purpose of this study was to investigate the impact of surfactants on the rate of crystal growth of amorphous celecoxib, both in the presence and absence of a polymer. Celecoxib is a poorly water-soluble non-steroidal anti-inflammatory drug. Such compounds may be formulated as amorphous solid dispersions to improve bioavailability, and solid dispersions can contain both a surfactant and a polymer. While the impact of polymers on crystal growth rates has been studied, the effect of surfactants is largely unexplored. Herein, the effect of sodium lauryl sulfate (SLS), sucrose palmitate and d-α tocopherol polyethylenglycol 1000 succinate (TPGS) at a 10% (w/w) concentration on the crystal growth rate of celecoxib was investigated. Linear crystal growth rates as a function of temperature (70-120 °C) were measured using optical microscopy. The mixtures were characterized using differential scanning calorimetry (DSC), infrared spectroscopy, and X-ray diffraction. The results indicate that the surfactants increase the crystal growth rate of amorphous celecoxib. However, addition of polyvinyl pyrrolidone (PVP) helped to mitigate the increase in growth rates, although the ternary systems were highly complex. Thus it is clear that the impact of a surfactant on the physical stability of an amorphous solid dispersion should be considered during formulation.