Enhancing Oral Absorption of β-Lapachone: Progress Till Date.

β-Lapachone is a naphthoquinone with high and diverse biological activity. It is useful to treat several pathologies, in particular cancer due to its ability to induce selective apoptosis in tumoral cells. Despite its advantages, β-lapachone's clinical applications are limited by its low solubility in biological fluids and its low specific distribution pattern. In the last decade various formulation strategies have been designed and developed in order to overcome these limitations and to make feasible its wide therapeutic use. The most relevant strategies for oral administration have been focused on the improvement of its solubility in order to increase β-lapachone oral bioavailability. The use of cyclodextrins or the inclusion of the active substance in micelles and microparticles has demonstrated to be successful approaches. For topical and local application temperature-sensitive hydrogels have been developed to achieve high target concentrations. Polymeric micelles administrated subcutaneously have proved to be a long-lasting circulating system and to increase accumulation in tumor tissue making them an interesting formulation strategy.