Determination of the binding parameter constants of Renagel capsules and tablets at pH 7 by high performance capillary electrophoresis

Sevelamer hydrochloride is a cross-linked polymeric amine; it is the active ingredient in Renagel capsules and tablets. Sevelamer hydrochloride is indicated for the control of hyperphosphatemia in patients with end-stage renal disease (ESRD). The binding parameter constants of sevelamer hydrochloride were determined using high performance capillary electrophoresis (HPCE) and the Langmuir approximation for three different dosage forms at pH 7.0. The three dosage forms were Renagel 403 mg capsules, Renagel 400 mg tablets and Renagel 800 mg tablets. The results demonstrate the in vitro bioequivalence of all three dosage forms at pH 7.0. These results are in very good agreement with previously published results obtained by ion chromatography.

Determination of the binding parameter constants of Renagel capsules and tablets utilizing the Langmuir approximation at various pH by ion chromatography

Sevelamer hydrochloride is a cross-linked polymeric amine; it is the active ingredient in Renagel capsules and tablets. Sevelamer hydrochloride is indicated for the control of hyperphosphatemia in patients with end-stage renal disease. The binding parameter constants of sevelamer hydrochloride were determined using the Langmuir approximation for three different dosage forms at pH 4.0, 5.5 and 7.0. The three dosage forms were Renagel 403 mg capsules, Renagel 400 mg tablets and Renagel 800 mg tablets. The results demonstrate the equivalency of all three dosage forms at each pH. The results also demonstrate a shift in the binding mechanism from pH 4.0 to 7.0.

Comparative evaluation of the antitumor activity of antiangiogenic proteins delivered by gene transfer

Although the systemic administration of a number of different gene products has been shown to result in the inhibition of angiogenesis and tumor growth in different animal tumor models, the relative potency of those gene products has not been studied rigorously. To address this issue, recombinant adenoviruses encoding angiostatin, endostatin, and the ligand-binding ectodomains of the vascular endothelial growth factor receptors Flk1, Flt1, and neuropilin were generated and used to systemically deliver the different gene products in several different preexisting murine tumor models. Single i.v. injections of viruses encoding soluble forms of Flk1 or Flt1 resulted in approximately 80% inhibition of preexisting tumor growth in murine models involving both murine (Lewis lung carcinoma, T241 fibrosarcoma) and human (BxPC3 pancreatic carcinoma) tumors. In contrast, adenoviruses encoding angiostatin, endostatin, or neuropilin were significantly less effective. A strong correlation was observed between the effects of the different viruses on tumor growth and the activity of the viruses in the inhibition of corneal micropocket angiogenesis. These data underscore the need for comparative analyses of different therapeutic approaches that target tumor angiogenesis and provide a rationale for the selection of specific antiangiogenic gene products as lead candidates for use in gene therapy approaches aimed at the treatment of malignant and ocular disorders.