Fast dissolving β-lapachone particles and tablets: an approach using surface adsorption technique

β-lapachone (βLAP) is obtained from natural resources with promising preliminary results against the etiologic agent of Chagas disease. βLAP activity is associated with generation of free radical and inhibition of nucleic acids and protein synthesis leading an outstanding antichagasic action. Low water solubility and large therapeutic doses constitute the main problems to overcome in the development of dosage forms of this drug.

The purpose of the present research was to enhance the limited dissolution rate of βLAP by promoting the spontaneous crystalline growth of βLAP on the surface of an inert excipient.

Physicochemical characterization of the particles was carried out as well as the drug dissolution rate. Drug adsorbed particles were compared to the drug as supplied and its physical mixtures with the inner excipient. The utility of the βLAP adsorbed particles in the development of tablets obtained by direct compression were also evaluated.

Particles produced by spontaneous crystalline growth of βLAP on microcrystalline cellulose (MCC) hydrophilic surface showed mean diameters between 55-65 µm and fast drug dissolution rate (90% drug dissolved at 50 min). Neither physical nor chemical instability of the drug were detected after the drug adsorption procedure. The compression process does not extensively deteriorate the dissolution behaviour of the systems when an adequate compression pressure is used.

Surface adsorption technique offers a simple way to produce βLAP powder and tablets with improved dissolution rate for oral administration.