The word "dispermin" is spelled as /dɪsˈpɜːmɪn/. This means that the first syllable is pronounced as "dis," the second syllable is pronounced with a short "e" sound followed by a stress on the third syllable, and the final syllable is pronounced with a short "i" sound. The word "dispermin" is not commonly used and its meaning is not clear. It is possible that the intended word was "spermicide" which is a type of birth control product.
Piperazin.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.