Tiapride is a medication which takes effect on the central nervous system and is used in the treatment of dyskinesias such as in chorea huntington and movement disorders, tic disease and tremor due to alcohol abuse.
I have dissolved the evaporation residues of tiapride droplets in ethyl alcohol and achieved a totally different result. The polarisation filter came in handy again.
Nonetheless it could be possible that the picture taken could be one of the additive agent potassium sorbate. As I do not possess the pure substance I am unable to make a comparison.