Influence of doxorubicin inclusion into phospholipid nanoformulation on its antitumor activity in mice: increased efficiency for resistant tumor model.

AIM: The new formulation of doxorubicin on the base of phospholipid nanoparticles (particle size <30 nm) is elaborated in the Institute of Biomedical Chemistry (Russian Academy of Medical Sciences) on the base of plant phospholipids. The aim of study is to investigate an antitumor effect of this nanoformulation in mice with two cancer models with various sensitivity to chemotherapy ­ lymphoid malignancy P-388 and Lewis lung carcinoma (LLC). METHODS: Nanophospholipid (NPh) formulation of doxorubicin was prepared by homogenization of soybean phosphatidylcholine and doxorubicin hydrochloride. The effect of this formulation was studied in experiments with single or threefold drug administration. Percents of tumor growth inhibition in mice under influence of free or NPh doxorubicin forms were compared. RESULTS: Single administration of both free and NPh doxorubicin in mice with P-388 resulted in the same quick severe inhibition of tumor growth (60­90% depending from dose), with further gradual decrease of inhibition degree. However for more resistant tumor, LLC, the obvious advantage of NPh doxorubicin form was shown. The little effect of free doxorubicin began to reveal only after 11 days, but NPh formulation induced significant inhibition of tumor growth (40%) from the first experimental point (6 days after administration). The advantages of NPh doxorubicin was manifested particularly in low drug doses, 2 and 4 mg/kg. In other experiment design in mice with LLC, with threefold weekly drug administration, NPh doxorubicin appeared to be 2.5 times more active than free drug. The reason of the same actions of free and NPh doxorubicin form in P-388 is suggested the high drug sensitivity of this model, that gives quick high drug response for any doxorubicin form. CONCLUSION: Doxorubicin in phospholipids nanoformulation revealed higher antitumor efficiency as compared with free doxorubicin in mice with LLC carcinoma. The mechanism of such changes is supposed to be caused by increase of doxorubicin availability for cancer cells.

[Possibilities for use of phospholipid nanosystem with glycyrrhizic acid ("phosphogliv") for optimization of drugs: doxorubicin and budesonide as examples].

The complexes of phospholipids nanoparticles (as the injection form of newly developed hepatoprotector phosphogliv) with the antitumor drug doxorubicin or with glucocorticoid budesonide have been investigated for their pharmacological activity in comparison with free forms of these drugs. Doxorubicin with phosphogliv revealed more antitumor and antimetastatic activity in C47B 1/6 mice with carcinoma LLC than free doxorubicin. Inhalation of budesonide with phosphogliv in vivo to quinea pigs resulted to more pronounced decrease of antigen or histamin induced bronchospasm, particularly its subacute phase, as compared with traditional powder or suspension budesonide forms. This suggests that the phosphogliv injection forms may be used not only for treatment of liver diseases, but also for delivery of a number of other drugs and consequently for optimization of their efficiency.

[Antirheumatoid activity of methotrexate in phospholipid nanoparticles (Phosphogliv)].

The efficiency of methotrexate use in basic therapy of rheumatoid arthritis is limited because of risk of side effects and fast drug efflux from zone of joints as well. The new stabilized form of methotrexate was elaborated with phospholipid micelles as a carrier. The injective form of the preparation Phosphogliv was used for this purpose. Phosphogliv has recently been developed in the Institute of Biomedical Chemistry (Moscow), as the emulsion of 50 nm phospholipid nanoparticles stabilized by glycyrrhizic acid. The conditions of maximal methotrexate incorporation into the phospholipid nanoparticles were optimised under control of HPLC (60% of total methotrexate was associated with nanoparticles, with remaining drug being in free form in the water phase). Such preparation revealed higher therapeutic efficiency in experimental adjuvant arthritis in rats as compared with free methotrexate. The increase of antirheumatoid activity of the elaborated preparation may also be attributed to the influence of glycyrrhizic acid, possessing both antiinflammatory and immune properties. The possibility of clinical employment of a new methotrexate drug form for rheumatoid arthritis treatment is discussed.