As discussed here before, there is apparently no approved...

As discussed here before, there is apparently no approved product containing propofol and TPGS. I couldn’t find one and nor could you. This was despite your previous assertion that Lusedra was an approved product containing propofol and TPGS and your further suggestion that there were other approved propofol formulations containing TPGS.

But we did agree that there was a patent for a propofol injectable formulation which contained TPGS (Bharat Serums and Vaccines Ltd – Priority Date 07/12/2000).

Now you have suggested that there is no difference between a TPM propofol formulation and a TPGS propofol formulation. In your mind, they are both simply “tocopheryl phosphate propofols”.

Now, while I agree that TPM and TPGS both have the words tocopheryl in them and both can function as solubilizing agents, to my mind, that doesn’t make them the same. Sydney Harbour Bridge and Princes Bridge, for example, both contain the word “bridge” and both function as bridges but I think that most people of sane mind wouldn’t consider them to be the same.

I would argue that if the TPM propofol and TPGS propofol formulations, as revealed in their respective patents, were the same, any patent examiner would have to recommend against patent approval of TPM propofol on the grounds of lack of novelty. But the international searching authority has found all claims of the TPM propofol patent application filed by Terumo and Phosphagenics to be novel.

I would also suggest that the disclosed compositions of the two formulations are quite different.


The TPGS propofol composition includes d-Alpha Tocopheryl Polyethylene Glycol 1000 Succinate (TPGS) in an amount from 1 to 20 % w/v, with at least ten times the weight of TPGS to propofol required.

The TPM propofol composition includes mono(tocopheryl) phosphate and di(tocopheryl) phosphate (TPM) in a total amount from 0.20 w/v% to 0.74 w/v%. In the example given, the weight of TPM used is just one quarter of that of propofol. The formulation also contains polysorbate 80 and polysorbate 20 which are said to work as solubilizers in conjunction with the TPM. The ratio of both the mono(tocopheryl)phosphate to di(tocopheryl) phosphate and the polysorbate 80 to polysorbate 20 can be adjusted (within a certain range).

To my (layperson’s) eye, these two “recipes” for a clear, stable propofol solution look quite different.

BTW, a patent search including Terumo and propofol shows that Terumo filed a patent application in 2011 (JP2012210315) for a pre-filled syringe container, suitable for propofol, that allows stable storage, transport and administration. That patent was granted in August 2015. In April the following year, Terumo entered into an R & D alliance with Phosphagenics for a TPM propofol formulation.

I guess that if you have a better propofol syringe container, it makes sense to fill it with a better propofol formulation.