This invention is for an improved process to co-encapsulate hydrophobic drugs and hydrophilic drugs in
phospholipid liposomes. Non-toxic supercritical or near-critical fluids with / without polar cosolvents are utilized to solubilize
phospholipid materials and hydrophobic drugs, and form uniform liposomes to encapsulate hydrophobic drugs and hydrophilic drugs.
DNA topoisomerase I (Top1) is the target of
camptothecin, and novel Top1 inhibitors are in development as anticancer agents. Top1 inhibitors
damage DNA by
trapping covalent complexes between the Top1 catalytic
tyrosine and the 3′-end of the broken
DNA. Tyrosyl-
DNA phosphodiesterase (Tdp1) can repair Top1-DNA covalent complexes by hydrolyzing the tyrosyl-DNA bond. Inhibiting Tdp1 has the potential to enhance the anticancer activity of Top1 inhibitors and to act as
antiproliferative agents. It has been recently reported that
neomycin inhibits Tdp1 more effectively than the related aminoglycosides
paromomycin and lividomycin A. Inhibition of Tdp1 by
neomycin is observed both with single- and double-stranded substrates but is slightly stronger with duplex DNA, which is different from aclarubicin, which only inhibits Tdp1 with the double-stranded substrate. Inhibition by
neomycin can be overcome with excess Tdp1 and is greatest at low pH.
Aminoglycoside antibiotics and the
ribosome inhibitors thiostrepton,
clindamycin-2-
phosphate, and
puromycin are the first reported pharmacological Tdp1 inhibitors. The development of Tdp1 inhibitors as anticancer agents can be envisioned as combinations of Tdp1 and Top1 inhibitors. Moreover, Tdp1 inhibitors might also be effective by themselves as anticancer agents. In addition, Tdp1 inhibitors might be valuable as anti-infectious agents.This invention can produce a co-encapsulated
combination drug product consisting of a
topoisomerase 1 inhibitor such as camptothecins including neat
camptothecin and its derivatives
irinotecan,
topotecan and other derivatives, and a tyrosyl-DNA
phosphodiesterase (Tdp1) such as
aminoglycoside antibiotics including neomycin and
tetracycline, and the
ribosome inhibitors thiostrepton,
clindamycin-2-
phosphate, and
puromycin.