The spelling of the word "ptelein" is quite unusual, but it is not without reason. In fact, the way it is spelled reflects its origin. This word is derived from the Greek language, and in Greek, the letter "p" is often inserted before words that begin with certain letters, including "t". Additionally, the "pt" combination is often pronounced with a silent "p" in Greek. Therefore, the IPA transcription of "ptelein" would be /ˈtɛlɪn/.
An alcoholic extract of ptelea, tonic in doses of gr. 1-3 (0.06-0.2).
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.