Vorinostat with Sustained Exposure and High Solubility in Poly(ethylene glycol)-b-poly(DL-lactic acid) Micelle Nanocarriers: Characterization and Effects on Pharmacokinetics in Rat Serum and Urine

The histone deacetylase inhibitor suberoylanilide hydroxamic acid, known as vorinostat, is a promising anti-cancer drug with a unique mode of action; however, it is plagued by low water solubility, low permeability, and suboptimal pharmacokinetics. In this study, poly(ethylene glycol)-b-poly(DL-lactic acid) (PEG-b-PLA) micelles of vorinostat were developed. Vorinostat’s pharmacokinetics in rats were investigated after intravenous (i.v.) (10 mg/kg) and oral (50 mg/kg) micellar administrations and compared to a conventional PEG400 solution and methylcellulose suspension. The micelles increased the aqueous solubility of vorinostat from 0.2 mg/ml to 8.15 ± 0.60 mg/ml and 10.24 ± 0.92 mg/ml at drug to nanocarrier ratios of 1:10 and 1:15, respectively. Micelles had nanoscopic mean diameters of 75.67 ± 7.57 nm and 87.33 ± 8.62 nm for 1:10 and 1:15 micelles, respectively, with drug loading capacities of 9.93 ± 0.21% and 6.91 ± 1.19 %, and encapsulation efficiencies of 42.74 ± 1.67% and 73.29 ± 4.78%, respectively. The micelles provided sustained exposure and improved pharmacokinetics characterized by a significant increase in serum half-life, area under curve, and mean residence time. The micelles reduced vorinostat clearance particularly after i.v. dosing. Thus, PEG-b-PLA micelles significantly improved the oral and intravenous pharmacokinetics and bioavailability of vorinostat, which warrants further investigation

Formulation of lipid polymer hybrid nanoparticles of the phytochemical Fisetin and its in vivo assessment against severe acute pancreatitis

Abstract Fisetin (FST) is a naturally occurring flavonol that has recently emerged as a bioactive phytochemical with an impressive array of biological activities. To the author knowledge, boosting the activity of FST against severe acute pancreatitis (SAP) through a nanostructured delivery system (Nanophytomedicine) has not been achieved before. Thereupon, FST-loaded lipid polymer hybrid nanoparticles (FST-loaded LPHNPs) were prepared through conjoined ultrasonication and double emulsion (w/o/w) techniques. Comprehensive in vitro and in vivo evaluations were conducted. The optimized nanoparticle formula displayed a high entrapment efficiency % of 61.76 ± 1.254%, high loading capacity % of 32.18 ± 0.734, low particle size of 125.39 ± 0.924 nm, low particle size distribution of 0.357 ± 0.012, high zeta potential of + 30.16 ± 1.416 mV, and high mucoadhesive strength of 35.64 ± 0.548%. In addition, it exhibited a sustained in vitro release pattern of FST. In the in vivo study, oral pre-treatment of FST-loaded LPHNPs protected against l-arginine induced SAP and multiple organ injuries in rats compared to both FST alone and plain LPHNPs, as well as the untreated group, proven by both biochemical studies, that included both amylase and lipase activities, and histochemical studies of pancreas, liver, kidney and lungs. Therefore, the study could conclude the potential efficacy of the novel phytopharmaceutical delivery system of FST as a prophylactic regimen for SAP and consequently, associated multiple organ injuries