Preparation and characterization of quercetin-polyvinylpyrrolidone K-30 spray dried solid dispersion

Context: The use of quercetin as a potential active pharmaceutical ingredient is limited by low aqueous solubility leading to low bioavailability. A spray-dried solid dispersion technique is used to increase the solubility and dissolution profiles of quercetin. Aims: To prepare and characterize quercetin solid dispersion using polyvinylpyrrolidone (PVP) K-30. Methods: Solid dispersions (SDs) were prepared by spray drying technique at quercetin/PVP K-30 ratios of 10/90, 20/80, 30/70, 40/60 and 50/50. A physical mixture of quercetin/PVP K-30 (50/50) and pure quercetin were used as comparisons. The SDs were characterized by powder X-Ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform IR (FTIR) spectroscopy, solubility and dissolution studies. The effect of the drug/polymer ratio on the solubility of quercetin was also studied. Results: Quercetin SDs appeared as amorphous form as confirmed by XRD. Quercetin was better dispersed as the drug/polymer ratio decreased. SD with ratio 10/90 showed regular spherical particles in the size range of 0-35 mu m. The solubility of quercetin increased with decreasing drug/polymer ratio. Preparation of SDs influence the solubility significantly (p<0.01). The increase in solubility is probably due to a hydrogen bond between quercetin and PVP K30 as confirmed by FTIR spectra. SD with ratio 10/90 showed a high dissolution rate (95.12 +/- 1.83%) within 120 min in comparison to pure quercetin (19.37 +/- 0.58%) or physical mixture (37.85 +/- 0.85%). Conclusions: Preparation of quercetin SDs with PVP K30 by spray drying technique results in amorphous spherical particles. There was an increase in solubility and percent dissolved with a decrease in drug/polymer ratio.