Thomas Harry Ferguson

Improved potency assay for recombinant bovine somatotropin by high-performance size-exclusion chromatography

A high-performance size-exclusion chromatographic method was developed for the determination of potency of recombinant bovine somatotropin (rbST) monomer and the estimation of dimer and soluble aggregates in bulk drug substances. These proteins can be completely extracted from bulk drug substances with sodium borate-ethylenediamine-tetraacetic acid disodium salt (EDTA) at pH 9.5 and separated on TSK G3000SW column with a mobile phase of pH 7.3 sodium borate-EDTA. The results demonstrated that this method was a non-denaturing assay for the determination of potency of rbST monomer and the data obtained in this study correlated well with data of the hypophysectomized rat body weight gain bioassay. The rbST monomer and dimer in the separation were verified by liquid chromatography-electrospray mass spectrometry. This method was optimized and validated.

Extraction and Quantification of Recombinant Bovine Somatotropin from Oleaginous Vehicle

Abstract A non-denaturing assay for the determination of potency of a recombinant bovine somatotropin (somidobove) formulated in oleaginous vehicles was developed. In this paper, the optimal conditions for extraction of somidobove from oleaginous vehicle were investigated. Results demonstrated that somidobove monomer, oligomers, and soluble aggregates were quantitatively extracted by borate - ethylenediaminetetraacetate (EDTA) pH 9.5 buffer solution in a VanKel dissolution system at 40°C for 3 hours. The extracted analytes, somidobove monomer, dimer, and soluble aggregates, were separated and determined by using a high performance size exclusion chromatographic system consisting of a TSK G3000SW column and a borate - EDTA buffer (pH 7.3) mobile phase. This method was validated for the effects of buffer type, extraction temperature, extraction time and stirring speed. The average CV of intra- and inter-day precision obtained in this method were 2.3%. The recovery of somidobove monomer was 93.7% with a coef...