Wetting agents poloxamer

The term poloxamer is widely used to describe a series of ABA block coploymers of polyethylene oxide and polypropylene oxide, extensively used in industry as antifoams, emulsifiers, wetting agents, rinse aids, and in numerous other applications [1-5]. Poloxamers are amphiphilic in character, being comprised of a central polypropylene oxide (PO) block, which is hydrophobic, sandwiched between two hydrophilic polyethylene oxide (EO) blocks as shown below ... 

Poloxamers are most important commercially as anti-foams, wetting agents, and emulsifiers, but have also been found to have numerous potential applications in the medical field. 

Therapeutically, poloxamer 188 is administered orally as a wetting agent and stool lubricant in the treatment of constipation it is usually used in combination with a laxative such as danthron. Poloxamers may also be used therapeutically as wetting agents in eye-drop formulations, in the treatment of kidney stones, and as skin-wound cleansers. 

Poloxamers are used as emulsifying agents for intravenous fat emulsions, as solubilising agents to maintain clarity in elixirs and syrups, and as wetting agents for antibacterials. They may also be used in ointment or suppository bases and as tablet binders or coaters. 

Poloxamer 217 Potassium rosinate Propylene glycol laurate Sodium 2-ethylhexyl sulfate Sodium myristyl sulfate Sodium octyl sulfate Steareth-2 Steareth-10 Steareth-20 Trideceth-3 Trideceth-6 Trideceth-9 Trideceth-12 wetting agent, agric C12-14 pareth-17 C12-14 pareth-22 wetting agent, agric. 

Poloxamer 105 Poloxamer 123 Poloxamer 181 wetting agent, flavoring agents PEG laurate... 

Typical excipients used in parenteral suspensions include surfactants that are used to stabilise emulsions and suspensions as wetting agents (polysorbate 80, poloxamer), as micelle makers for the preparation of solubilisations and to influence the flocculation and deflocculation behaviour of a dispersed system (carmellose sodium, polyvidone). Paren-terally used surfactants in high concentrations are toxic and may cause venous irritation and occasional thrombophlebitis. However, these high concentrations are not necessary to formulate stable parenteral suspensions. 

Adeka PEG-200 Adeka PEG-300 Adeka PEG-400 Adeka PEG-600 Adeka PEG-1000 Adeka PEG-1500 Adeka PEG-4000 Adeka PEG-6000 Adeka PEG-20,000 Cawet-130 Plonon 102 Plonon 104 Plonon 108 Plonon 171 Plonon 172 Plonon 201 Plonon 204 Plonon 208 wetting agent, syndet bars Antarox F-88 FLK Poloxamer 238 wetting agent, synthetics Sera Wet M-EJW Ultravon 7065 Ultra-von SFN... 

To improve wetting, surfactants with an HLB larger than 15 are used, such as sodium dioctyl sulfosuccinate (Aerosol OT ), ethoxylated castor oil, poloxamer, sodium salts of higher alcohol sulfates (sodium lauryl sulfate) and polysorbates, but also polymers with interfacial activity as, for example hydrogel formers as methylcellulose, hypromellose, etcetera. A further discussion of these substances can be found in Sects. 23.6 and 23.7. In practice, propylene glycol or a thickening agent will lower the interfacial tension to a sufficient extent. 

Dispersion of the powder in the vehicle. This requires adequate wetting of the powder (external and internal surfaces) by the liquid vehicle, necessitating the use of a wetting/dispersing agent, mostly a nonionic surfactant (such as poly-sorbates) or polymeric surfactant (such as Poloxamer). This process is described in detail in Chapter 7. 

Figure 9.19 The relationship between (a) Tween 80 concentration, (b) benzethonium chloride concentration, (c) the concentration of several poloxamers as marked and adhesion from a 15% suspension of chloramphenicol in a container with 6.5 cm glass wall, (d) the effect of anionic surface-active agents SLS (sodium lauryl sulphate) and SCS (sodium cetyl sulphate) on adhesion (Ad) and the amount of trapped and retained suspension (Re) x 0.25. Adhesion determined at 40° C after 48 h after a single wetting of the surface. From Uno and Tanaka [47] with permission.

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