[Doreen]

@MarkBroussard
The impossibility to preserve lecithin emulsified products against molds, is that (amongst other reasons) due to the interaction with parabens?
I don’t use lecithin as emulsifier, but I have a few products that contain medium/high levels of lecithin:

- Rovisome CE Plus (Evonik, INCI: Water (>50%), Pentylene Glycol (10-25%), Lecithin (10-25%), Alcohol (1-5%), Ascorbyl Palmitate (1-5%), Tocopherol (0.1-1%), Potassium Phosphate (0.1-1%);
- Phytrox LTR15-IP MB (Jan Dekker (IMCD), INCI: Lecithin (sunflower lecithin: EU approved food additive E322), Ascorbyl Palmitate, Tocopherol (d-mixed tocopherols: d-β, d-γ, d-δ), Rosmarinus Officinalis Extract, Helianthus Annuus Seed Oil)

Rovisome CE Plus I use between 1-3% and Phytrox LTR15-IP MB at 0.1 - 0.5%.
Do you think these low levels of lecithin in the product (emulsions) can be used together with parabens at the maximum of the recommended levels?

I totally understand if you say that I should do tests to find out, but I thought maybe it has been researched from what level of lecithin there is significantly deactivation of parabens, like with some non-ionics.

[Doreen]

Distilled and deionized water.

[Doreen]

@Bill_Toge
I think ngarayeva001 uses a stick blender.

[Doreen]

@ngarayeva001 

96%… I heard controversial opinions about tetrahexadecyl ascorbate. Some papers suggest it works but the sample is too small. I used 10% for a couple of months (made it myself, I don’t think you can buy it at a such concentration) and didn’t notice any difference.

Apparently there are several brands using it at 20% to even (way) higher.
I have documents regarding, but unfortunately I still can’t upload files here.

[Doreen]

@Pharma What I meant in my earlier reply was that maybe one of the forms has the lidocaine incompatibility (OH-), maybe the other, cyano- hasn’t? And that the latter form is used in the i.m. injections that you mention? Again, I really can’t imagine two incompatible substances that might give precipitation when put together, being mixed in one syringe.

@Belassi
You mentioned availability of the B12.
For me it’s the cheapest way to use the solution for injection in hydroxocobalamine form (in the research they used cyanocobalamine, but the powder is quite expensive here). If you can’t find the pure powders, maybe you can get hold of the injection solution too? Just a tip.

[Doreen]

@Pharma
So? I have never seen two incompatible substances being put together in one syringe, nor for immediate i.m. use or otherwise.

[Doreen]

Ascorbyl palmitate has a low solubility and poor rate of dissolution in oil (30 mg/100 ml at room temperature). Do you add it to the heated oil phase?

[Doreen]

@Pharma
The Cyanokit is exactly the same. It’s hydoxocobalamine in a higher dose.

[Doreen]

@Belassi
I read about it being used topically for atopic dermatitis.
https://www.ncbi.nlm.nih.gov/pubmed/15149512

[Doreen]

@Pharma
Maybe it’s the form that matters (hydroxo or cyano), regarding incompatability with lidocaine? I read the warning not to use hydroxocobalamine together with i.a. lidocaine in the same IV line (and thus couldn’t be mixed in the same syringe either) due to ‘chemical incompatability’ in the Cyanokit booklet (page 23)
The i.m. injection isn’t painful at all though?

[Doreen]

I’m formulating a cream with vitamin B12 for a family member with atopic dermatitis:
https://chemistscorner.com/cosmeticsciencetalk/discussion/5900/usefullness-and-stability-vitamin-b12-in-creams

I’ll post updates in my thread. If the results are promising, maybe it could be an idea for you dog as well?

Have you tried oatmeal? You could make an oatmeal ‘bath’ for example.
Or in a cream (Graham’s Eczema cream contains 2.5% colloidal oatmeal).

[Doreen]

I misspelled some symptoms (Dutch instead of English).

I also want to thank Pharma and amitvedekar for info about buffers and pH (I see I only mentioned Sibech and chemicalmatt). I’ve been too hasty, it’s terribly late (or actually very early) here and I’m in dire need of sleep. :flushed:
And thank ALL of you who have replied, I really value your input very, very much!

I’ll keep you informed about how things went!

[Doreen]

@Perry @Pharma @Sibech @chemicalmatt @amitvedakar
Thank you all so much for your answers!

@Perry

You wanted me to clarify the first question ‘1. Does anyone know how stable OH-cobalamine is in an emulsion?’

What I mean with ‘stable’:  how easily  is the substance decomposed, oxidized.

I know that OH-cobalamine (also) needs to be protected against light, so that’s one thing.

I would  expect an emulsion with 0.07% to turn pink as both cyano- & OH-cobalamine are bright red in colour and a red colorant was used in the double blind research to make the placebo look exactly the same.

There are many incompatabilities known with pharmaceutical substances, like diazepam, fentanyl, lidocaine etc,but  I wondered if there are incompatabilities known with excipients like emulsifiers, preservatives. 

@Pharma

Both cyano- as OH-cobalamine injections are indeed buffered. Not all manufacturers use the same excipients though.

Are you sure you aren’t confused with another substance, regarding painful injections? OH-cobalamine is incompatible with lidocaine and (unless used for cyanide intoxication) never administered intravenously, only intramuscular and subcutaneous.

I have to inject myself i.m. with B12 every three months (I’m a vegetarian + a thyroid disfunction which usually goes together with troubled B12 uptake, enteral pathway of B12 is complicated) and I can’t really say that it’s painful. At least not as notorious as propofol for example, which burns down the veins even with lidocaine (what I remember from being anesthetized decades ago).

A strange (but explainable) side effect of B12 injections: a lot (1 in 10) of users get acneiform dermatitis (luckily I’m not one of them). Hopefully this won’t happen when used topically to the family member that I will be making it for.
(@Sibech you’re right, I typed this answer + scheme when I only got answers from Perry and Pharma)

I made a quick scheme.

Availability and price

1. Cyanocobalamine :

- injections only used for Schillingtest i.m.;

- most (or only) used B12 form for topical application at 0.07%;

- powder form available on local DIY site, but extremely pricey.

2. OH-cobalamine:

- injections only used for B12 deficiency  i.m./s.c. and cyanide/smoke poisoning (i.v.);

- solution for injection (0.5 mg/ml) available, these are rather cheap.

Interactions/incompatabilities

- Incompatibility with several pharmaceutical substances, but no corticosteroids were listed, so I guess there are either no known interactions or it’s unknown (family member uses topical corticosteroids during severe outbreaks);

- Interaction with vitamin C.

Side effects

- Acneiform dermatitis when used parenterally in both lower and higher doses, topically unknown;

- (FYI for all readers of this forum): When used in large doses (≥ 5 gram parenterally):

several (serious) side effects mentioned, like raising of blood pressure, ventriculair extrasystoles (‘extra’ heartbeats, paradoxically seems to feel like heart is ‘missing’ a beat), high levels of calcium oxalate in urine (kidney stones), acute kidney failure and necrosis, lowering % of lymphocytes, restlessness, pleural effusion (excessive fluids around the lungs), dyspnoe (shortage of breath), reversible red discoloration of skin and mucous membranes, chromaturia (red discoloration urine), pustular exanthema, peripheral oedema, gastrointestinal symptoms like diarrhea, nausea, effect on laboratory tests: raised glucose, cholesterol, albumin, protein, creatinine and lowered amylase and ALAT (=liver enzyme).

(The side effects on the kidneys (-failure and -necrosis) were perceived in patients that were treated with high levels of B12 ánd suspected or diagnosed with cyanide poisoning, all the other symptoms (also) perceived in healthy patients.)

May this be a reminder for everyone not to overdo when using vitamin supplements (especially parenterally).

Recommended dose

I will go with the 0.07% topical cyanocobalamine used in the researches.

I guess I can use 0.07% OH-cobalamine as well. Difference in dose between two forms should be negligible.

Stability

Protect against light

I will be using OH-cobalamine solution for injections 0.5 mg/ml.

Excipients used in the solution:

- hydrochloric acid, NaCl, water for injections (Takeda)

- acetic acid and NaOH, NaCl, water for injections, benzyl alcohol (Centrafarm)

I’ll use the ampoules from Takeda, as these have less excipients and don’t need to be stored in the fridge.

I’ll first try to make it without a buffer at a pH of about 6.
(Thanks Sibech and chemicalmatt for your help!!)

And I’ll weigh the solution first so I can go with % w/w instead of w/v .

Regarding red colorants: I’ve tried Gromwell root (CO2) extract a while ago. I needed only the tiniest speck to turn almost half a kilogram of emulsion from white into pink. (It should turn into a blue hue when the product is alkaline instead of neutral or acidic.)

Edit: adjusted lay-out

[Doreen]

@Perry @Pharma
I didn’t see your replies yesterday, didn’t get a notification.
I will read both of your replies thoroughly and respond later, thanks very, very  much!!

[Doreen]

@tinj
You’re very welcome.

[Doreen]

@Nubian
True. Xanthan is anionic and most gelforming polymers are.

[Doreen]

I would lower the cetearyl alcohol (and panthenol as well) and personally I would add a gelforming polymer. Varisoft also contains cetearyl, and my personal experience is that a too high % of fatty alcohols can become ‘drying’.

[Doreen]

@MarkBroussard
I now see that what I took for the 40C line is actually the 60C line and the lower temperatures indeed don’t increase the conjugated diene forming significantly. Thanks for pointing it out!
(The used medium in this graph is pure sunflower oil by the way (without other additions). I have no idea how and if the graph would change when it would be e.g. an emulsion.)

What concentration would you recommend for skin benefits?

[Doreen]

Dr Catherine Pratt said:

Sorry did you already mention that..

Only Perry can delete a post, and I saw too late that the reply I wrote was already given, so I changed my post to ‘already answered’. (as my post had become unnecessary, but unfortunately I can’t delete it.)

[Doreen]

@Dtdang
Tocopherol acetate doesn’t have antioxidant activity in the product or raw ingredient, so best to use ‘pure’ tocopherol for that reason (which is amber coloured). And as Mark rightfully mentions it’s not very stable, so indeed a good idea to pair it up with the substances that he mentions.
Disadvantage of (alpha-)tocopherol is that you shouldn’t exceed 0.2% or it can become pro-oxidative (see graph below).

Personally I never use tocopherol acetate. I don’t see a good reason for it.

Edit: gamma and delta tocopherol don’t become ‘pro-oxidative’ in higher doses. Manufacturer Jan Dekker for example has products without alpha-tocopherol, so these can be used in higher %.
Source (document):

@Perry
I still can’t upload files in replies, only in private messages.

[Doreen]

Am I really the first here to ask about topical vitamin B12? ?
Hopefully not the last.

[Doreen]

@Pharma
Correct. I see a lot of homecrafters using vitamine E capsules (the acetate form) as antioxidant for their product, but it’s useless for that reason.

Simply put:
Tocopheryl acetate => as skin ‘active’
Tocopherol => as antioxidant for product or raw ingredients (e.g. vegetable oils), no more than 0.2% or it stimulates oxidation rather than inhibits.

[Doreen]

@bellbottom
?

What about these! ?

[Doreen]

Colour is usually amber to light brown, certainly not white. 

(Source of picture)

[Doreen]

@Pharma
Thanks for your reply.
I didn’t know that brand, thanks for mentioning.

Hopefully I can get some answers to my questions.