Bioanalysis

Bioanalysis is a specialized sub-discipline of analytical chemistry, primarily concerned with the quantitative measurement of biotic and xenobiotic substances in biological systems. Biotics refer to naturally occurring macromolecules, proteins, DNA, large molecule drugs, and metabolites, while xenobiotics pertain to drugs, their metabolites, and other foreign biological molecules present in unusual locations or concentrations.

Overview

Bioanalysis plays a pivotal role in multiple scientific disciplines, enabling accurate quantification of both drugs and endogenous substances in biological specimens. In the realm of the pharmaceutical industry, bioanalysis delivers quantitative data on active drugs and their metabolites, facilitating research in areas like pharmacokinetics, toxicokinetics, bioequivalence, and exposure–response studies. Additionally, the scope of bioanalysis extends to illegal drug use, forensic examinations, anti-doping tests in athletics, and ecological concerns.

Traditionally, bioanalysis was predominantly concerned with small molecule drugs. However, the surge in biopharmaceuticals (such as proteins and peptides) over the last two decades has redefined the landscape, presenting new challenges for quantification.

History

Bioanalytical studies tracing drugs in biological fluids originated in the nascent field of forensic medicine and toxicology, aiming to detect potential overdoses. Early techniques were nonspecific, failing to distinguish between a drug and its metabolites. For instance, drugs like aspirin and sulfonamides were quantified using colorimetric assays, while antibiotics were gauged by their potency against bacterial proliferation. The 1930s marked the emergence of pharmacokinetics, spurring the demand for more specific assays. Contemporary drugs, being more potent, necessitated refined bioanalytical assays to reliably determine these drugs at minuscule concentrations, prompting technological advancements and improved analytical methods.

Bioanalytical Techniques

Bioanalytical research employs a myriad of techniques, including:

• Hyphenated Techniques:
  • LC–MS
  • GC–MS
  • LC–DAD (liquid chromatography–diode array detection)
  • CE–MS

• Chromatographic Methods:
  • HPLC
  • GC
  • UPLC (ultra performance liquid chromatography)
  • Supercritical fluid chromatography

• Other Techniques:
  • Electrophoresis
  • Ligand binding assays, including:
    • Dual polarisation interferometry
    • ELISA
    • MIA
    • RIA
  • Mass spectrometry
  • Nuclear magnetic resonance

Predominantly, liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) is used for small molecules, while enzyme-linked immunosorbent assay (ELISA) is favored for macromolecules.

Sample Preparation and Extraction

Given the complex nature of biological samples, various extraction techniques are implemented to segregate the analyte from potential interfering substances. Common methodologies include:

• Protein precipitation
• Liquid–liquid extraction
• Solid phase extraction

To address the sheer volume of samples from clinical trials and other sources, bioanalytical labs increasingly resort to automated sample preparation processes and liquid-handling robots to optimize efficiency and minimize expenses.

Bioanalytical Organizations

Globally, numerous national and international bioanalytical organizations operate, often as subsets of larger entities. Notable examples include the Bioanalytical Focus Group and Ligand Binding Assay Bioanalytical Focus Group, both under the American Association of Pharmaceutical Scientists (AAPS), and FABIAN, associated with the Analytical Chemistry Section of the Royal Netherlands Chemical Society. Conversely, the European Bioanalysis Forum (EBF) functions independently, unaffiliated with any overarching society or association.