The present invention provides a method of extracting an asymmetric \u03b2-diketone compound from a \u03b2-diketone compound containing at least one symmetric \u03b2-diketone compound mixed in the asymmetric \u03b2-diketone compound, and the method includes the step of adjusting a pH of a mixed solution of the \u03b2-diketone compound and water at 11. More particularly, this invention is directed to a suppository based vaccine delivery system for the prophylaxis against or treatment of urogenital or anorectal transmitted infectious diseases, such as from viral or microbial pathogens. In some embodiments, the system further includes an illumination scanner configured to scan a surface of the sample with at least a portion of apodized illumination.