Optimization of Unnicked β2-Glycoprotein I and High Avidity Anti-β2-Glycoprotein I Antibodies Isolation

Patient biological material for isolation of β2-glycoprotein I (β2GPI) and high avidity IgG anti-β2-glycoprotein I antibodies (HAv anti-β2GPI) dictates its full utilization. The aim of our study was to evaluate/improve procedures for isolation of unnicked β2GPI and HAv aβ2GPI to gain unmodified proteins in higher yields/purity. Isolation of β2GPI from plasma was a stepwise procedure combining nonspecific and specific methods. For isolation of polyclonal HAv aβ2GPI affinity chromatographies with immobilized protein G and human β2GPI were used. The unknown protein found during isolation was identified by liquid chromatography electrospray ionization mass spectrometry and the nonredundant National Center for Biotechnology Information database. The average mass of the isolated unnicked purified β2GPI increased from 6.56 mg to 9.94 mg. In the optimized isolation procedure the high molecular weight protein (proteoglycan 4) was successfully separated from β2GPI in the 1st peaks with size exclusion chromatography. The average efficiency of the isolation procedure for polyclonal HAv anti-β2GPI from different matrixes was 13.8%, as determined by our in-house anti-β2GPI ELISA. We modified the in-house isolation and purification procedures of unnicked β2GPI and HAv anti-β2GPI, improving the purity of antigen and antibodies as well as increasing the number of tests routinely performed with the in-house ELISA by ~50%

Investigation of drug product and container-closure interactions: A case study of diluent containing prefilled syringe.

Prefilled syringes (PFS) constitute a widely used medical device for drug delivery particularly for the drugs of biological origin. Interactions between the product contents and the components of the PFS play a critical role in determining the suitability of selected PFS. A diluent (with benzyl alcohol/BzOH as a preservative) containing PFS used for reconstitution of the lyophilized product revealed a systematic decrease in the BzOH content during accelerated and stress stability program. Investigation was carried out to understand and identify the underlying causes of this phenomenon. BzOH has a varying propensity to bind to the rubber components (stopper and tip-cap) of the PFS. Vapor permeation behavior across the tip-cap of the PFS was studied via headspace-gas chromatography-mass spectroscopy (HS-GC-MS) enabled analysis. Depending on the properties of the rubber components, BzOH can not only bind but also traverse across them, resulting in a systematic loss during the course of the stability. PFS can allow not only water vapor permeation across the tip-cap as shown in previous studies, but also molecules like benzyl alcohol. This phenomenon stresses the need for careful selection of the components of the primary packaging and also provides an opportunity to deploy novel tools like HS-GC-MS in the early selection of the optimal primary packaging configuration