UPLC-MS/MS method for determination of sofosbuvir in human plasma.

INTRODUCTION: A sensitive and rapid method for quantitation of Sofosbuvir in human plasma has been established using ultra performance liquid chromatography-electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS). MATERIALS AND METHODS: Sofosbuvir d3 was used as an internal standard. Sofosbuvir and internal standard in plasma sample were extracted using ethyl acetate (liquid liquid extraction). A centrifuged upper layer was then evaporated and reconstituted with the mobile phase of 0.5% formic acid: methanol (30:70, v/v). The reconstituted samples were injected into a Gemini C18 (50×4.6mm, 5µm) column. RESULTS: Using MS/MS in the multiple reaction monitoring mode, Sofosbuvir and Sofosbuvir d3 were detected without severe interferences from human plasma matrix. Sofosbuvir produced a protonated precursor ion ([M+H]+) at m/z 428.35 and a corresponding product ion at m/z 279.26. The internal standard produced a protonated precursor ion ([M+H]+) at m/z 431.38 and a corresponding product ion at m/z 282.37. The calibration curves for the analyte was linear (R2≥0.9956, n=4) over the concentration range of 4.063-8000.010ng/mL. Stability studies revealed that Sofosbuvir was stable in plasma during bench top (7h at room temperature), in injector (20h), at the end of five successive freeze and thaw cycles and long term at -70°C±15°C for 15 days. CONCLUSION: The developed method was validated as per the guidelines of USFDA and the obtained results were found to be within the limits and could be successfully employed for the determination of Sofosbuvir in human plasma for regular and pharmacokinetic studies.

A multicenter prospective hospital-based surveillance to estimate the burden of rotavirus gastroenteritis in children less than five years of age in India.

BACKGROUND: Rotavirus is the leading cause of severe, dehydrating diarrhea in children aged <5 years globally, with an estimated 25 million outpatient visits and 2 million hospitalizations attributable to rotavirus infections each year. The aim of this hospital-based surveillance was to summarize the local epidemiological and virological features of rotavirus and to estimate the disease burden in the population under surveillance in India. METHODS: During the 16 months surveillance period from April 2011 through July 2012, a total of 4711 children under the age of 5 years were admitted with acute diarrhea at 12 medical centers attached to medical schools throughout India. Stool samples were randomly collected from 2051 (43.5%) subjects and were analyzed for rotavirus positivity using commercial enzyme immunoassay kit (Premier Rotaclone Qualitative Elisa) at the respective study centers. Rotavirus positive samples were genotyped for VP7 and VP4 by reverse-transcription polymerase chain reaction (RT-PCR) at a central laboratory. RESULTS: During the study period, maximum number of rotavirus related hospitalizations were reported from December 2011 through February 2012. Out of the 2051 stool samples tested for rotavirus, overall 541 (26.4%) samples were positive for rotavirus VP6 antigen in stool. The highest positivity was observed in the month of December, 2011 (52.5%) and lowest in the month of May, 2011 (10.3%). We found that majority of the rotavirus positive cases (69.7%) were in children <24 months of age. The most common genotypes reported were G1 (38%), G2 (18%), G9 (18%), G12 (9%) and mixed strains (17%). CONCLUSIONS: The results of this study confirm the significant burden of acute rotavirus gastroenteritis as a cause of hospitalizations in under five children in India.

How much will it cost? Estimation of resource needs and availability for HIV prevention, treatment and care for people who inject drugs in Asia.

As countries in Asia strive to meet their universal access targets, harm-reduction programmes are yet to be scaled up to reach effective levels of coverage. Resource tracking and estimation of resource needs and gaps is critical to inform the financing decisions of major donors of harm-reduction programmes in the region. This study aimed at estimating the financial resource needs and gaps for scaling-up harm reduction in the region, building on previous research conducted by the Independent Commission on AIDS in Asia. The overall resource need for achieving universal access in the target population in 2009 was US $0.5 billion, with NSP and OST accounting for nearly 70% of the overall regional resource need. A significant resource gap, approximately 90%, of the resource need in 2009, was identified for harm reduction in the region, representing less than 2% of the overall global resource need to address AIDS. Additional resources will be required to support the introduction and scaling-up of integrated, comprehensive harm-reduction programmes that provide a full range of services to reduce HIV transmission among people who inject drugs.