**5. Conclusion**

Doxorubicin is an effective anti-cancer drug that has high MDR incidence. High expression of an efflux transporter P-gp is one established mechanism responsible for the loss of drug effectiveness and MDR development. This can be due to the P-gp function in preventing intracellular accumulation of doxorubicin up to its effective level. Several approaches have been introduced in order to increase the efficacy of doxorubicin-based chemotherapy and overcome MDR. The combination of doxorubicin and non-cytotoxic P-gp modulators, particularly when given to the specific target cancer can be a promising approach to increase cancer sensitivity to doxorubicin through suppression of P-gp function. With the novel encapsulation technologies, it is very possible to develop the drug delivery platforms with specific targeted cancer cells as well as improvement of doxorubicin delivery into the cells. By these means, enhancement of doxorubicin-mediated cytotoxicity can be achieved with minimal dosing of the anti-cancer drugs. After clinically approval, it will provide a great benefit to patients receiving doxorubicin-based chemotherapy.
