Evaluation of the maximum beyond-use-date stability of regular human insulin extemporaneously prepared in 0.9% sodium chloride in a polyvinyl chloride bag

Megan A Rocchio, Caryn D Belisle, Bonnie C Greenwood, Michael C Cotugno, Paul M SzumitaDepartment of Pharmacy, Brigham and Women's Hospital, Boston, MA, USABackground: Regular human insulin 100 units added to a sufficient quantity of 0.9% sodium chloride, to yield a total volume of 100 mL within a polyvinylchloride bag, is accepted to be stable for 24 hours due to physical denaturation and chemical modification. The objective of this study was to evaluate the extended stability of such extemporaneously prepared regular human insulin, stored under refrigeration, to the maximum beyond-use-date allowed by United States Pharmacopeia chapter 797.Methods: At time “0” three admixtures of regular human insulin were prepared by withdrawing 1 mL of regular human insulin with a concentration of 100 units/mL and adding it to a sufficient quantity of 0.9% sodium chloride for injection in a polyvinylchloride bag to yield a total volume of 100 mL. The three admixtures were stored under refrigeration (2°C–8°C [36°F–46°F]), and one sample of each admixture was withdrawn and tested in duplicate at 0, 6, 24, 48, 72, 144, 168, 192, 216, 240, 312, and 336 hours. Utilizing high performance liquid chromatography, each sample underwent immediate testing. The time points were stable if the mean concentration of the samples exceeded 90% of the equilibrium concentration at 6 hours.Results: The equilibrium concentration was 0.89 units/mL. Time points were stable if the mean concentration was at least 0.80 units/mL. All time points retained at least 90% of the equilibrium concentration, with the exception of hour 168 (0.79 ± 0.03 units/mL). At 192 hours the mean concentration was 0.88 ± 0.03 units/mL. At 336 hours the mean concentration was 0.91 ± 0.02 units/mL.Conclusion: Based on these results, regular human insulin 100 units added to 0.9% sodium chloride for injection in a polyvinylchloride bag to yield a total volume of 100 mL is stable for up to 336 hours when stored at 2°C–8°C (36°F–46°F).Keywords: insulin, stability, storage, temperature, USP 797, sodium chloride, polyvinylchlorid

Induction of il21 in peripheral t follicular helper cells is an indicator of influenza vaccine response in a previously vaccinated HIV-infected pediatric cohort

HIV-infected patients of all ages frequently underperform in response to seasonal influenza vaccination, despite virologic control of HIV. The molecular mechanisms governing this impairment, as well as predictive biomarkers for responsiveness, remain unknown. This study was performed in samples obtained prevaccination (T0) from HIV-infected children who received the 2012-2013 seasonal influenza vaccine. Response status was determined based on established criterion for hemagglutination inhibition titer; participants with a hemagglutination titer >= 1: 40 plus a >= 4-fold increase over T0 at 3 wk postvaccination were designated as responders. All children had a history of prior influenza vaccinations. At T0, the frequencies of CD4 T cell subsets, including peripheral T follicular helper (pTfh) cells, which provide help to B cells for developing into Ab-secreting cells, were similar between responders and nonresponders. However, in response to in vitro stimulation with influenza A/California/7/2009 (H1N1) Ag, differential gene expression related to pTfh cell function was observed by Fluidigm high-density RT-PCR between responders and nonresponders. In responders, H1N1 stimulation at T0 also resulted in CXCR5 induction (mRNA and protein) in CD4 T cells and IL21 gene induction in pTfh cells that were strongly associated with H1N1-specific B cell responses postvaccination. In contrast, CD4 T cells of nonresponders exhibited increased expression of IL2 and STAT5 genes, which are known to antagonize peripheral Tfh cell function. These results suggest that the quality of pTfh cells at the time of immunization is important for influenza vaccine responses and provide a rationale for targeted, ex vivo Ag-driven molecular profiling of purified immune cells to detect predictive biomarkers of the vaccine response

Diagnosis, classification, basis of treatment of hyperphenylalaninemias

Neonatal mass screening is the common way to identify hyperphenylalaninemias (i.e. plasma Phe greater than or equal to 120 mu M similar to 2 mg/dl, Tyr less than or equal to 140 mu M similar to 2.5 mg/dl) due to Phenylalanine hydroxylase system deficiency. Once hyperphenylalaninemia (hyperPhe) has been detected, a complete diagnostic work-up must be applied to exclude defects in cofactor metabolism. While a tetrahydrobiopterin (BH4) defect is ruled out, the determination of plasma Phe concentration is the clue to differentiate the different degrees of enzyme deficiency: 1) Phe > 1000 mu M (16.5 mg/dl): classic PKU with mandatory Phe restricted diet; 2) Phe between > 600 mu M (similar to 10 mg/dl) e < 1000 mu M (16.5 mg/dl): 2) Phe type II with Phe restricted diet following the individual tolerance; 3) Phe steadily and on normal diet < 600 mu M (similar to 10 mg/dl): hyperPhe type III, without needing of treatment.The Phe restricted diet prevents mental retardation and neurological impairment. The goal of the treatment is to maintain plasma Phe levels between 120 and 360 mu M (similar to 2 and 6 mg/dl. In BH4 deficient patients dietary treatment, when needed, must be combined with pharmacological therapy to restore adequate levels of BH4 and specific neurotransmitters.This is thew first italian official report (one of the few worldwide published) on the topic