Poloxamers/pluronics

Poloxamer Pluronic Mol. wt. of P block Chain length, n Weight % of E block Chain length, m Mol. wt. of copolymer... 

A biocompatible, biodegradable polymer can be produced as follows. A poloxamer (Pluronic F68) (30) is dried in vacuo at about 105°C for 14 h. Afterwards, glycolide and then -caprolactone are added. As a catalyst stannous octoate is used (29). 

An example of the commonly used polymer in pharmaceutical systems is the A-B-A block copolymer of polyethylene oxide-polypropylene oxide-polyethylene oxide, PEO-PPO-PEO, commercially available as Poloxamers, Pluronics (BASF). On hydrophobic drug particles or oil droplets, the polymer adsorbs with the B hydrophobic chain (PPO) close to the surface, leaving the two hydrophilic A chains dangling in solution. These nonionic polymers provide stabilization against flocculation and/or coalescence by a mechanism usually referred to as steric stabilization [9]. In order to understand the principles of steric stabilization, one must first consider the adsorption and conformation of the polymer at the solid/liquid or liquid/liquid interface. The PPO chain adsorbs on the surface with many attachment points forming small loops , whereas the A chains (sometimes referred to as tails ) extend to some distance (few nm) from the surface [10]. 

Poloxamer Pluronic Molecular m+ Percent Molecular Total... 

Various biodegradable polymers, including poly anhydrides, poly orthoesters, hyalmonic acid, alginate, chitosan, and starch as well as poloxamers (Pluronics), which self-assemble into particulates, and polyphosphazenes have been investigated... 

The poloxamers manufactured by BASF (Cheadle, UK) are known as Pluronic PE block copolymers those manufactured by ICl (Cleveland, UK) as Synperonic PE nonionic surfactants. 

Polyoxyethylerie-polyoxypropylene block copolymers (Pluronics or Poloxamer) 29.0... 

Solubilization oftropicamide, a poorly water-soluble mydriatic/cycloplegicdrug, by poloxamers or Pluronics was studied (Saettone et al., 1988). The polymers evaluated as solubilizers for the drug included L-64, P-65, F-68, P-75, F-77, P-84, P-85, F-87, F-88, and F-127. The authors measured a range of physicochemical properties, such as solubility oftropicamide in polymer solutions, partition coefLcient of the drug between isopropyl myristate and copolymer solutions, critical micelle concentration of the copolymers, and viscosity of the copolymeric solutions containing tropicamide. 

Pluronics are the trade name of Poloxamers from the BASF company, which are composed of a central hydrophobic chain of polyoxypropylene [poly(propylene oxide)] flanked by two hydrophilic chains of polyoxyethylene [poly(ethylene oxide)]. For the generic term poloxamer, these copolymers are commonly named with the letter P (for poloxamer) followed by three digits. For the Pluronic trade name, coding of these copolymers starts with a letter to define its physical form at room temperature [L = liquid, P = paste, F = flake (solid)] followed by two or three digits. 

In this present study we report the effect of graded doses of y-irradiation on the properties of the micelles of Pluronic FI27 and on the temperature induced micellar changes which lead to the eventual gelation of these solutions. In view of the batch variability of the micellar properties of poloxamers (3) comparisons have been made with solutions of the same batch which have not been subjected to irradiation. 

Poloxamer Polyethylene-propylene glycol, Lutrol, Pluronic BP, PhEur, USPNF Melting point =50 °C... 

The first commercially developed emulsion, Fluosol-DA (Green Cross Corp. Osaka, Japan), was stabilized using a mixture of 6 and F-tripropylamine (FTPA, 7, 30% of total PFC) (Table 2). However, the product s stability was still poor Fluosol had to be frozen for shipment and storage, and reconstituted prior to use. Fluosol utilized a surfactant system that included poloxamer-188 (Pluronic F-68) with smaller amounts of EYP and potassium oleate. The poloxamer provided steric stabilization, and potassium oleate introduced negative charges on the droplets, likely to oppose flocculation. 

Another 20 /o w/v emulsion, trade-name Perftoran, based on an FDC and F-[l-(4-methylcyclohexyl)piper-idine] (FMCP, 8) mixture emulsified with a poloxamer was developed in Russia (Russian Academy of Sciences/ Perftoran Company, Pushshino, Russia). " Perftoran is filter-sterilized and stable for about 1 month at 4-8°C but requires freezing for longer storage. The Russian health authorities licensed it in 1997 for a wide range of indications. A highly stable 20 /o w/v F-tributyl-amine/Pluronic F-68 emulsion, Fluosol-43 (later renamed Oxypherol), was commercially available for many years for experimental use. 

Poloxamers are neutral block copolymers such as 12, consisting of two terminal hydrophilic polyoxyethylene blocks flanking a central hydrophobic polyoxypropylene block. Poloxamer 188 (e.g., Pluronic F-68) was used in the first generation PFC emulsions, but was far from adequate Its surface activity is relatively poor, translating into low emulsions stability the purity of the commercial products is usually rather low its cloud point ( 110-115°C) prevents sterilization at the standard temperature of 121°C its tendency to form gels limits the PFC concentration in the emulsions and, finally, Pluronic F-68 has been found to be responsible for the unpredictable transientcomplement activation-mediated anaphylactic reaction observed in some patients in response to the injection of Fluosol. ... 

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