INDEX poloxamer

Poloxamer 331 occurs as a practically colorless liquid. It is a block copolymer condensate of ethylene oxide and propylene oxide with an average formula weight of 3800, a specific gravity of about 1.02, and a refractive index of about 1.452. It is very slightly soluble in water at 25°, but is freely soluble at 0° it is freely soluble in alcohol, but is insoluble in propylene glycol and in ethylene glycol. 

U.S. Food and Drug Administration (2003, Nov. 7), Inactive ingredient search for approved drug products, poloxamer, available http /www.accessdata.fda.gov/scripts/ cder/iig/index.cfm, accessed May 21, 2006. 

Most cubic phases in lipid-water systems exhibit unit cell parameters not larger than 20 mn, while the imit cell of cubic membranes is usually larger than 100 nm. Some exceptioi have been apparently found [131, 132] although at this stage such findings should be treated with caution, as the determination of lattice parameters is dependent on the indexing of diffraction patterns, based only on a small niunber of reflections. Further, in lipid-protein-water, lipid-poloxamer-water and lipid-cationic surfactant-water systems, cubic phases with cell parameters of the order of 50 nm have been observed [56,127, 128]. Due to the small number of reports dealing with the... 

Figure 1 Molecular weight distribution of poloxamers 407 and 188, analyzed by gel permeation chromatography and refractive index detection.

Abbreviations PCS photon correlation spectroscopy, PDI polydispersity index, SlOO purified soybean lecithin Lipoid SlOO, E80 purified egg yolk lecithin Lipoid E80, SGC sodium glycocholate, SML sucrose monolaurate, GS gelatin succinate, SC sodium caseinate, PVA polyvinyl alcohol Mowiol 3-83, POL poloxamer 188 and TET poloxamine 708. 

Table 6.3 Peak Molecular weight (Mp) and polydispersity index (PI) for the two distributions found in poloxamer 407...

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