Product of the Month October: Lactic Acid

Lactic Acid – A Versatile Laboratory Chemical with Biotechnological Potential

Lactic acid (2-hydroxypropanoic acid) is much more than just a metabolic byproduct in the human body. In chemical and pharmaceutical research, it has established itself as a versatile laboratory chemical, with applications ranging from synthesis and analytics to biotechnology.

Origin and Production

Lactic acid naturally occurs in many biological processes, such as anaerobic glycolysis. Industrially, it is now predominantly produced biotechnologically via fermentation – typically from carbohydrates like glucose or sucrose using lactic acid bacteria (e.g., Lactobacillus spp.).

Biotechnological production offers several advantages:

• Sustainability through the use of renewable raw materials

• High enantiomeric purity (L- or D-lactic acid)

• Good scalability for industrial applications

Alternatively, chemical synthesis routes also exist, such as from acetaldehyde or acrylic acid, though these are less common.
Lactic acid contains a stereogenic center → L- and D-enantiomers. Chiral purity is especially important in pharmaceutical applications, as biological activity can be enantiomer-specific.

Applications in the Laboratory and Industry

1. Chemical Synthesis

Lactic acid serves as a starting material or intermediate for:

• Polymerization to polylactide (PLA) – a biodegradable plastic

• Production of lactates (e.g., ethyl lactate) as solvents

• Synthesis of chiral molecules in organic chemistry

2. Analytics

In clinical chemistry, lactic acid is used to determine lactate levels in blood – an important parameter in cases of shock, hypoxia, or metabolic disorders. In laboratories, it also serves as a reference substance or reagent in enzymatic tests.

3. Pharmaceutical Research

• Used as an excipient in topical formulations (e.g., peels, creams)

• Included in antiseptic solutions for wound care

• Acts as a pH regulator in pharmaceutical preparations

4. Biotechnology

• Substrate in microbial fermentation processes

• Component of cell culture media

• Used in the development of drug delivery systems (e.g., PLA-based microparticles)
Storage and Safety

Lactic acid is hygroscopic and should be stored in airtight containers in a cool environment. It is classified as an irritant and may cause skin or eye irritation upon contact. Appropriate protective equipment (gloves, safety goggles) is recommended when handling in the lab.

Lactic acid is a highly interesting laboratory chemical that stands out due to its biological origin, chirality, and wide range of applications in research and industry.