ABSTRACT:Sevelamer is an orally administered weakly basic anion exchange resin which consists of crosslinked polymeric amine that binds dietary phosphate in the gastrointestinal tract. This is approved for the treatment of hyperphosphatemia in adult patients with end-stage renal disease. The binding parameter constants of nonabsorbable sevelamer in its hydrochloride form were determined using the Langmuir approximation for its active pharmaceutical ingredient and 400 mg generic tablet dosage form (Sevel) at pH 4.0, 5.5 and 7.0. The binding parameters were also compared with the innovator product Renagel 400 mg tablet. The results demonstrate the equivalency of the dosage form at each pH in terms of the in vitro binding parameters. The results also demonstrate a shift in the binding mechanism from pH 4.0 to 7.0.

Neutronic and burnup assessment of an LWR based SMR core with Transuranic Fuel (TRU) was carried out and compared with UO2 fuel and mixed oxide fuel (MOX) for different core composition and configurations. Eight different cores were modeled by changing the fuel composition and loading pattern of four different fuel assemblies namely UO2, MOX, TRU, and annular UO2 fuel and simulated in open-source Monte-Carlo code OpenMC. The radial neutron flux distribution and maximum to average flux ratio were studied. The lowest flux ratio was found in Annular-2 models whereas TRU models showed the highest value. The effect of enrichment, fuel burnup, moderator to fuel ratio, and soluble boron concentration on effective multiplication factor (k_eff) was investigated. Burnup analysis of fissionable materials and neutron poison was performed. Burnup dependent fission rate of U-235, Pu-239, and Pu-241 was also studied. The composition of spent fuel at EOC was investigated and lower minor actinides (MAs) production was observed for TRU models. This analysis would help to determine the effectiveness and feasibility of these potential core configurations and to predict their neutronic behavior.