An improved size exclusion-HPLC method for molecular size distribution analysis of immunoglobulin G using sodium perchlorate in the eluent.

Size exclusion (SE) high performance liquid chromatography (HPLC) is widely used for the molecular size distribution (MSD) analyses of various therapeutic proteins. We report development and validation of a SE-HPLC method for MSD analyses of immunoglobulin G (IgG) in products using a TSKgel SuperSW3000 column and eluting it with 0.4M NaClO, a chaotropic salt, in 40mM phosphate buffer, pH 6.

Protein Nitrogen Determination by Kjeldahl Digestion and Ion Chromatography.

We report development and validation of a simple, rapid, and accurate method for the quantitation of protein nitrogen, which combines Kjeldahl digestion and ion chromatography with suppressed conductivity detection and requires nanomolar amount of nitrogen in samples (≥10 μg protein). The mechanism of suppressed conductivity detection does not permit analysis of samples containing copper (present in Kjeldahl digestion solution) and aluminum (present in many vaccines as adjuvants) due to precipitation of their hydroxides within the suppressor. We overcame this problem by including 10 μM oxalic acid in Kjeldahl digests and in the eluent (30 mM methanesulfonic acid).

Evaluation of growth based rapid microbiological methods for sterility testing of vaccines and other biological products.

Most biological products, including vaccines, administered by the parenteral route are required to be tested for sterility at the final container and also at various stages during manufacture. The sterility testing method described in the Code of Federal Regulations (21 CFR 610.12) and the United States Pharmacopoeia (USP, Chapter <71>) is based on the observation of turbidity in liquid culture media due to growth of potential contaminants.