Poloxamer

Overview

File:Poloxamere General Formula V2.svg

General chemical structure of a poloxamer.

Poloxamers are a class of synthetic block copolymers composed of a central hydrophobic block of polypropylene oxide (PPO) flanked by two hydrophilic blocks of polyethylene oxide (PEO). These copolymers are also known by the trade name Pluronic. The unique structure of poloxamers allows them to function as surfactants, emulsifiers, and solubilizing agents in various pharmaceutical and industrial applications.

Chemical Structure

Poloxamers are characterized by their ABA block structure, where "A" represents the hydrophilic PEO block and "B" represents the hydrophobic PPO block. The general formula for a poloxamer is (PEO)x-(PPO)y-(PEO)x, where x and y denote the number of repeating units of each block. The molecular weight and the ratio of PEO to PPO can be varied to tailor the properties of the poloxamer for specific applications.

Properties

Poloxamers exhibit unique thermoreversible gelation properties. At low temperatures, they are typically liquid, but they can form gels at higher temperatures. This property is particularly useful in drug delivery systems, where the poloxamer can be injected as a liquid and then form a gel at body temperature, providing sustained release of the drug.

Applications

Poloxamers are widely used in the pharmaceutical industry as excipients in drug formulations. They enhance the solubility and bioavailability of poorly soluble drugs. In addition, poloxamers are used in topical formulations, ophthalmic solutions, and as stabilizers in emulsions and suspensions.

In the industrial sector, poloxamers are used as detergents, dispersants, and emulsifiers. Their ability to stabilize emulsions makes them valuable in the formulation of cosmetics and personal care products.

Related Pages

• Surfactant
• Emulsifier
• Polyethylene oxide
• Polypropylene oxide
• Drug delivery system