Poly(n-butylcyanoacrylate) nanoparticles for oral delivery of quercetin: preparation, characterization, and pharmacokinetics and biodistribution studies in Wistar rats

Background: Quercetin (QT) is a potential bioflavonol and antioxidant with poor bioavailability and very low distribution in the brain. A new oral delivery system comprising of poly(n-butylcyanoacrylate) nanoparticles (PBCA NPs) was introduced to improve the oral bioavailability of QT and to increase its distribution in the brain. Physicochemical characteristics, in vitro release, stability in simulated gastric fluid and intestinal fluids, and pharmacokinetics and biodistribution studies of QT-PBCA NPs coated with polysorbate-80 (P-80) were investigated. Objective: This study aimed to investigate the physicochemical characteristics, in vitro release, stability in simulated gastric fluid and intestinal fluids, and pharmacokinetics and biodistribution studies of QT-PBCA NPs coated with polysorbate-80 (P-80). Results: The results showed that QT-PBCA NPs and QT-PBCA NPs coated with P-80 (QT-PBCA+P-80) had mean particle sizes of 161.1 +/- 0.44 nm and 166.6 +/- 0.33 nm respectively, and appeared spherical in shape under transmission electron microscopy. The mean entrapment efficiency was 79.86%+/- 0.45% for QT-PBCA NPs and 74.58%+/- 1.44% for QT-PBCA+ P-80. The in vitro release of QT-PBCA NPs and QT-PBCA+ P-80 showed an initial burst release followed by a sustained release when compared to free QT. The relative bioavailability of QT-PBCA NPs and QT-PBCA+ P-80 enhanced QT bioavailability by 2.38- and 4.93-fold respectively, when compared to free QT. The biodistribution study in rats showed that a higher concentration of QT was detected in the brain after the NPs were coated with P-80. Conclusion: This study indicates that PBCA NPs coated with P-80 can be potential drug carriers for poorly water-soluble drugs. These NPs were observed to improve the drugs' oral bioavailability and enhance their transport to the brain.