Melt crystallization of ibuprofen on surfaces patterned by a Nd : YAG laser

Abstract

Surface-based control of melt crystallization of ibuprofen (IBU) is reported. The substrates in the present study included glass, flat Au, and laser-patterned Au. The IBU crystal morphologies were regulated depending on the surfaces where IBU crystallization was induced, and spherical, sunflower-like, and dendritic morphologies were obtained. Especially, the dendritic morphology of a large surface area was observed on the novel laser-patterned surfaces. Three-dimensionally tortuous Au structures were achieved by a 532 nm Nd : YAG laser, of which Gaussian beam profile was reshaped into a flat-top contour using a custom-designed diffusing system. Also, the effect of poly-e-caprolactone was analyzed as a crystallization modulating additive to fine-tune the IBU crystal morphologies. The IBU crystallization behaviors as well as the laser patterning processes are described as a part of the ongoing efforts to develop a general strategy to utilize heterogeneous nucleation and directional growth to control the crystallization of important organic compounds, such as active pharmaceutical ingredients.