Particle characterization and analysis in therapeutic protein formulation

Abstract

The aim of the study was characterization and analysis of particles in protein formulation. Characterization of particles was carried out by compendial method such as light obscuration (LO). But it has limitations for detecting various particles such as glass, silicone oil droplets, air bubble, proteinaceous and non-proteinaceous particles. The US and EU pharmacopeias require sub-visible particle (SbVP) analysis of parenteral drug products. hence there was a requirement of an orthogonal method which can analyze, quantify and characterize particles on parameters such as size, morphology, optical density etc. Micro Flow Imaging (MFI) was the orthogonal method available which could characterize and quantify particles on the basis of their morphology. Therefore, the main aims of the study were 1) Development of a method which could differentiate between proteinaceous and non-proteinaceous particles and also transluscent and transparent particles. 2) Comparative evaluation of compendial method i.e. LO and orthogonal method i.e. MFI. The method development for MFI and comparative evaluation was carried out using polystyrene beads standards, which showed comparable results. After that placebo and real protein formulation were analyzed for the same. MFI was able to provide more information regarding particle morphology and the particle subpopulation based on their morphological filters. Considering advantages and limitations of both methods, MFI was proved to be more sensitive method with respect to counting accuracy and size accuracy. hence quantification and characterization of protein formulations with both LO and MFI had provided more information regarding the particle morphology and particle nature, which helps in the development of stable and potentially safe protein therapeutic products.