Introduction and background

Monoclonal antibodies (mABs) are monovalent immunoglobulin molecules that bind only to the same epitope. These antibodies have a wide range of applications such as in diagnostics, analytics, and as drugs in the treatment of cancer and other autoimmune diseases. The emerging market of mAB biosimilars demands proper characterization after previously performed isolation of these molecules. Isolating these antibodies however is quite a challenge and was first done by Georges Köhler and César Milstein, for which they were awarded the Nobel prize in medicine and physiology in the year 1984.

In this small blog article, we would like to explain two terms often mixed up during analytical method validation. It’s about specificity and selectivity.

Specificity

According to the official guideline to be applied for method validation ICH Q2(R1), specificity is defined as:

“Specificity is the ability to assess unequivocally the analyte in the presence of components which may be expected to be present.”

Introduction and background

Recombinant human tissue Plasminogen Activator (rt-PA), the synthetic version of Tissue plasminogen activator (tPA), is a serine protease involved in degradation of blood clots. As a drug it is used for the treatment of stroke. It functions by converting plasminogen into plasmin, which in turn degrades insoluble fibrin into soluble by-products. This process of converting fibrin into soluble by-products is called fibrinolysis.

Introduction and background

Fulvestrant or Faslodex is a drug used to cure hormone receptor-positive (HR+) metastatic breast cancer in postmenopausal women with disease progression. It belongs to the group of Selective Estrogen Receptor Downregulators (SERD) and is often considered a suitable replacement for Tamoxifen. It functions by binding to the estrogen receptor and destabilizing it, promoting degradation by the cell's normal protein degradation mechanism. For Fulvestrant’s content determination in pure and pharmaceutical dosage form or its purity, there has been no HPLC (High Performance Liquid Chromatography) or LSV (Linear Sweep Voltammetry) methods reported thus far. In this post, we would like to highlight such methods, developed by Atila et al., with focus on their advantages and compliance to method validation.