import re
pat = re.compile(r'''\b
(?: i
(?: ntra
(?: cerebroventricular (?:ly)?
| duodenally
| gastric (?:ly)?
| muscular
| peritoneal (?:ly)?
| venous (?:ly)?
) \b
| \.? (?: [gmpv] | c \.? v ) \b \.?
)
|
(?:per)? oral (?:ly)? \b
|
p \.? o \b \.?
|
subcutaneous (?:ly)? (?: \s+ injection )? \b
)''', re.I | re.X)
s = 'Pharmacokinetics parameters evaluated after single IV or IM'
print(pat.findall(s))