Synthesis and behaviour of ester derivatives of 4-isobutylphenyl-2-propionic acid (ibuprofen) with end-hydroxylated poly(N-vinylpirrolidinone) and poly(N-acryloyl morpholine) oligomers

Four derivatives of 4-isobutylphenyl-2-propionic acid (Ibuprofen), in
which the drug was bound by ester linkages to poly(ethylene glycols) (PEG 2000-I),
monomethoxy poly(ethylene glycols) (PEG 1900-I), poly(N-vinyl pyrrolidinone) (PVPI)
and poly(N-acryloyl morpholine) (PACM-I), all having approximatively the same
number average molecular weight (M̄(n) ~ 2000), were prepared and tested for their
pharmacokinetic properties after oral administration. It was found that the two
end-hydroxylated amphiphilic oligomers of polyvinylic structure, PACM and PVP,
whose physico-chemical properties are comparable to those of PEGs especially as
regards solvent affinity, have in principle a similar potential as promoieties for
preparing oligomeric prodrugs.