Sara Majd Jabbari

Background: Sofosbuvir (SOF) is a revolutionary treatment for patients with hepatitis C virus (HCV). However, its efficacy and safety among patients with end-stage renal disease (ESRD) remains controversial. In this study, we examined the levels of SOF metabolite (GS-331007) (SOF-007) in human plasma of patients infected with HCV having ESRD using an optimized liquid chromatography-mass spectrometry (LC-MS) analytical method. Methods: In this case-control study, 10 clinically confirmed cases and five controls were enrolled. SOF-007 was extracted from plasma using methanol precipitation. The limit of detection (LOD) for the drug and its metabolite were 0.85 and 2.3, respectively. Such a wide range of quantification in a period of separation time shorter than 3.0 minutes (run time) allowed monitoring of the plasma concentration of analytes up to 4 hours (pre-dialysis and post-dialysis) for 12 weeks in non-cirrhotic patients with HCV infection undergoing dialysis. Results: SOF-007 in the plasma of HCV patients with healthy kidneys showed no cumulative effect. An analysis comparing patients with ESRD and healthy participants showed that their behaviour was similar, followed by dialysis with a relatively small cumulative effect. Conclusion: The plasma concentrations of SOF-007 decreased significantly after the 4-hour period of dialysis compared with the plasma concentrations hemodialysis of pre-dialysis in HCV patients with ESRD.

The present study deals with preparation and optimization of a novel chitosan hydrogel‐based matrix by suspension cross‐linking method for controlled release of Depo‐Medrol. The controlled release of Depo‐Medrol for effective Rheumatoid arthritis disease has become an imperative field in the drug delivery system. In this context, it was intended to optimize loading circumstances by experimental design and also study the release kinetics of Depo‐Medrol entrapped in the chitosan matrix in order to obtain maximal efficiency for drug loading. The optimum concentrations of chitosan (2.5 g), glutaraldehyde (3.05 μL) and Depo‐Medrol (0.1 mg) were set up to achieve the highest value of drug loaded and the most sustained release from the chitosan matrix. In vitro monitoring of drug release kinetic using high‐performance liquid chromatography showed that 73% of the Depo‐Medrol was released within 120 min, whereas remained drug was released during the next 67 h. High correlation between first‐order and Higuchi's kinetic models indicates a controlled diffusion of Depo‐Medrol through the surrounding media. Moreover, recovery capacity >82% and entrapment efficiency of 58–88% were achieved under optimal conditions. Therefore, the new synthesized Depo Medrol–chitosan is an applicable appliance for arthritis therapy by slow release mechanism. Copyright © 2016 John Wiley & Sons, Ltd.