emo >99% Pure - what does it mean?

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6 years 9 months ago #99

Hi All,

I may be misunderstanding what it means to say that the Mesochem drugs are >99% pure.

Does it mean that there are <1% impurities in them, ie. ingredients other than the pure drug as manufactured by Mesochem?

Or does it mean that the Mesochem drug is >99% similar to the brand name drug, ie. almost identical to the brand name drug?

Or what?

Thanks, dointime

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6 years 9 months ago #106

Making a medication is not a lot different to a chemistry experiment or for that matter a back yard meth lab. Typically you add two chemicals together in a solvent, heat it to such an such a temperature for a while, do something to make what you want separate from what you don't, then rinse and repeat.

What this means in practical terms is that at the end of manufacture you have a lot of the thing you want (which is the > 99%) and a whole lot of traces of things you don't want, but can not easily separate. Traces of solvents (from the process), traces of metals (from the containers used in manufacture), and traces of molecules similar, but not identical, to what you have been trying to produce.

Here is the official Chinese analysis of Mesochem's Sofosbuvir API fixhepc.com/images/coa/COA-Sofosbuvir.pdf


YMMV

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6 years 9 months ago #107

Hi Dr Freeman,

Many thanks for this answer.
So if I'm understanding you correctly, >99% Pure means >99% free of impurities.
It does NOT say anything about the medication being an accurate copy of the brand name drug, therefore it does NOT imply that similar results to the brand name drug can be expected.

So which is the test that shows that the Mesochem drug is an accurate copy of the brand name drug? I take it that that would be the NMR Comparison test. I would like to get an NMR comparison test on any drugs that I receive. Do you know how / where could I get this done?

Best wishes,
dointime

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6 years 9 months ago #109

Doesn't chemistry logic dictate that you have to first identify the chemical that you are testing before you can test it's purity? If you didn't start with that premise, every chemical you tested would logically be made up 100% of impurities.

Last Edit: 6 years 9 months ago by Alsdad.

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6 years 9 months ago #110

Hi Alsdad

Yes, that would make sense. Mesochem, being the manufacturer, would know exactly which chemical it had manufactured and was testing for impurities. It could name that chemical whatever it wanted to, Mesovir for example. Their testing might then find that their Mesovir had <1% impurities in it.

But if we wanted to know if Mesovir was an accurate copy of, say, Sofosbuvir then we would need to run an NMR comparison to compare Mesovir with Sofosbuvir, as Dr Freeman has done and posted his results here on the website.

dointime

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6 years 9 months ago #112

99% purity means 99% pure medication + 1% other stuff, mostly solvents used in manufacturing.

Testing is complex, but here it is in a nutshell:

Mass Spectrometry establishes the exact ratio of atoms present, so water would be H20 and Sofosbuvir is C22H29FN3O9P

Mass spec can also see impurities like stuff that you do not want including heavy metals like Lead, Arsenic, Tin....

Now Mass Spec tells you what atoms are present in what ratios but does not tell you how they are arranged. A technology called NMR tells your the exact arrangement. You can see a simple overview of our results here:

fixhepc.com/blog/item/2-sofosbuvir-ledip...r-and-mass-spec.html

That's abbreviated. The full set of tests done have included:

  • Mass Balance
  • NMR
  • qNMR
  • 2D NMR
  • HPLC
  • ELSD
  • Karl Fischer
  • Thermogravimetric Analysis

We have proven reference samples of these materials and can test any imported material against these.


YMMV

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6 years 9 months ago #115

Dr Freeman,

Thank you very much for this explanation. It is indeed exciting to see the results that you have obtained. Are you continuing to test random batches that you receive? You say that you tested a batch of Mesochem Sof and Led. Haveyou done any testing on Daclatasvir so far?

Best,
dointime

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6 years 9 months ago #117

We have tested all of Sofosbuvir, Ledipasvir, and Daclatasvir at a local facility and they all look good.

We have tested every individual dose to date, with the exception of one patient who could not afford the cost (but we had tested ever other sample from that batch). He's at SVR so it worked, but it made me worry about "What if?"

Going forward we have negotiated a slightly reduced price from Mesochem if we batch up orders, so we will be able to include the testing with patients not paying any more.

For me testing is my protection - Yes, your honour, I prescribed a Hep C medication to a Hep C patient and I had confidence in that because....

And for patients..... I use the mum test. Would I be happy with my mum getting this treatment in this way?


YMMV
The following user(s) said Thank You: Archer

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6 years 9 months ago #118

Wow, that sounds really really good and a process that a patient could trust. I wish I could get my meds tested like that. Do you have any suggestions on how I could do that? Maybe I should just come to Tasmania. I'm half joking, but why not. I am already looking at travelling to Delhi or Beijing to get meds based on trusting the supplier and minimizing the supply line. Your testing is better still.

Are you using the Daclatasvir then for some people? I am interested to know how it is decided to use Daclatasvir rather than Ledipasvir. I see that there could be financial reasons (led costs at least 4 x dac) but are there clinical reasons why it is more appropriate in some situations?

I am also just curious - what genotype do you see most of in your area, if one type is prevalent?

Thanks,
dointime

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6 years 9 months ago #123

In Australia we are 54% G1a/G1b and 37% G3a. So that accounts for 91%. We've seen quite a lot of G2, probably because Sof/Riba is not a bad choice for it and that's what came online first out of India and we don't really have G4 G5 G6 here.



I'm pretty sure I can find a colleague in the UK who will help in which case we could arrange something.

Price is probably the major decision maker in Led vs Dac for someone with G1. For G3 it's definitely Dac. For G2 you'd be tossing up Sof+Riba vs Sof+Dac.

It will almost certainly change as more data becomes available.


YMMV

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6 years 9 months ago #125

Dr Freeman,

Many thanks for this information. I am still trying to absorb the implications for me of the comprehensive testing that you have done on the Mesochem drugs. This new information, that the Mesochem drugs are indeed identical to the brand name, puts them on a par with the Indian licensed generics.

The hepC landscape is moving very fast. Sometimes it seems to change daily. I want to consider my options till around Xmas this year and start tx early in the New Year. I don't wish to trouble you with extra work when you obviously have your hands full already, but I may very well wish to take you up on the offer of finding a colleague in the UK who could replicate the testing for me that you are doing.

Best wishes,
dointime

Best wishes,
dointime

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6 years 9 months ago #128

Dr freeman,

Regards my getting testing done in the UK, I do not have proven reference samples of the brand name drugs for comparison purposes. Would you expect your colleague to supply these?

DT

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