Chromatography Forum

Dear Friends,

Can any one help on estimation of tween 40 in pharmaceutical formulations as my formulation contain it as an ingradient and it is effecting the dissolution release. i am unable to find the literature in this regard. Looking for your responce

Thanks in advance.
G.R.Reddy,
India.

if you want to estimate tween 80 then you can use hplc but detector you shall have to use elsd. your mobile phase will be volatile should not contain salt, you can use 0.1% tfa(trifluroacetic acid) in water as mobile phase a and 0.1% tfa in acetonitrile as mobile phase b and with waters symmetry column you can proceed.,flow you can give 1ml/min, drift tube temp you can keep 80.0°c and then you shall have to go with trial and error for separating your peak from main peak.

The Tween surfactants (also called polysorbate) are complex mixtures, not single peaks. The USP description gives you an idea: Polysorbate 40 is a palmitate ester of sorbitol and its anhydrides copolymerized with approximately 20 moles of ethylene oxide for each mole of sorbitol and sorbitol anhydrides. We have analyzed them by HPLC, and they are not pretty.

Perhaps conversion of the palmitate to the methyl esters and GC would be viable.

At high concentrations, Tween 80 can be detected by UV absorption at ~ 233 nm (I am not sure if this is the same for Tween 40 – I think it would be) .

For more precise analysis the typical assay is LC-MS. A contract testing lab that offers this is : West Coast Analytical . See http://www.wcaslab.com/special/pharm2.htm

Note: When analyzing protein solutions by SEC-HPLC (a major part of my life), it is common to get high molecular weight peaks that show up unexpectedly and are not reproducible (at the column void volume). Often this is due to Tween micelles.

I will look at a UV spectral scan (from a PDA detector) to differentiate aggregated protein from detergent micelles.