Stability of Immunoglobulins in OraCAb to Simulated Gastric Fluid (SGF)

Simulated gastric fluid, pH 1.2 was prepared according to the US Pharmacopeia and contained 2 g NaCl, 7 ml 37% HCl and 3.2 g porcine pepsin (8000 U) (Sigma) made up to a liter with water for irrigation. OraCAb was evaluated for stability of immunoglobulins to SGF. SGF was mixed with OraCAb formulation in different ratios (10% OraCAb, 20% OraCAb, 30% OraCAb, 40% OraCAb, and 50% OraCAb in SGF). The mixtures were incubated for 2.5 h at 37°C with gentle shaking every 15 min. At the end of the incubation, pH was increased by adding Phosphate Buffered Saline (PBS) to prevent further protein digestion by the pepsin in SGF. Samples were then analyzed by the toxin neutralization assay.