intraperitoneal
adjective
in·tra·per·i·to·ne·al ˌin-trə-ˌper-ə-tə-ˈnē-əl 
: existing within or administered by entry into the peritoneum
intraperitoneal chemotherapy
intraperitoneally
ˌin-trə-ˌper-ə-tə-ˈnē-ə-lē
adverb 
Example Sentences
Recent Examples on the Web Not only would this be more acceptable to and comfortable for patients, especially children, than intravenous, intraperitoneal and subcutaneous routes. 
Philip W. Askenase, Scientific American, 17 June 2020
Philip W. Askenase, Scientific American, 17 June 2020 Word History
First Known Use
circa 1836, in the meaning defined above
Medical Definition
intraperitoneal
adjective
in·tra·per·i·to·ne·al ˌin-trə-ˌper-ət-ᵊn-ˈē-əl
: situated within or administered by entering the peritoneum