Development of solid dispersions of β-lapachone in PEG and PVP by solvent evaporation method.

β-lapachone (βlap) has shown potential use in various medical applications. However, its poor solubility has limited its systemic administration and clinical applications. The aim of this work is to develop solid dispersions of βlap using poly (ethylene glycol) (PEG 6000) and polyvinylpyrrolidone (PVP K30) as hydrophilic polymers and evaluate the dissolution rate in aqueous medium. Solid dispersions were prepared by solvent evaporation method using different weight ratios of βlap and hydrophilic polymer (1:1, 1:2, and 1:3). Characterization performed by differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy showed that βlap was molecularly dispersed within the polymer matrix. The in vitro dissolution tests showed an enhancement in the dissolution profile of βlap as solid dispersions prepared in both PVP and PEG, although the former showed better results. The drug:polymer ratio influenced βlap dissolution rate, as higher amounts of hydrophilic polymer led to enhanced drug dissolution. Thus, this study demonstrated that solid dispersions of βlap in PVP offers an effective way to overcome the poor dissolution of βlap.