Smoking alternatives: Do e-cigs provide the optimal alternative? What voltage is optimal? Nicotine

[JW50]

Below is an abstract of some research that deals with PG. It is found here: ScienceDirect - International Journal of Pharmaceutics : Effect of energy on propylene glycol aerosols using the capillary aerosol generator and deals with “optimal aerosolization” of PG. Thinking of the e-cig as an aerosol generator the question arises as to what voltage (and resistance) of vaping gives the most optimal delivery of nicotine.

Effect of energy on propylene glycol aerosols using the capillary aerosol generator

X. Shen , M. Hindle , and P. R. Byron
Aerosol Research Group, Department of Pharmaceutics, Virginia Commonwealth University, Box 980533, 410 North 12th St., Richmond, VA 23298-0533, USA
Received 13 March 2003; Revised 11 September 2003; accepted 9 February 2004. Available online 27 March 2004.
Abstract
The CAG is being developed for pulmonary drug delivery. Liquids are pumped, heated and vaporized by the CAG, whence they nucleate and condense to form aerosols. This study characterized the effect of energy on the aerosolization process. With increasing energy, the CAG produced an increasing fine particle fraction (FPF) until “optimal aerosolization” was achieved between 40 and 45 J; this energy range agreed with that theoretically required to vaporize the dose of PG. Further increases in energy above this optimal range did not improve PG’s aerosolization efficiency. Based on the energy, FPF and temperature profiles, it was possible to deduce the nature of the liquid flow-boiling during aerosol generation. The aerosol particle size went through a minimum, as energy was increased through the “optimal range.” In the “energy excess” region, where additional energy increased PG vapor temperature and velocity, droplet sizes were increased primarily due to changes in the nucleation rates and supersaturation ratios affecting the nucleation and condensation processes occurring within the vapor jet. The in vitro MMAD of the PG aerosol changed as a function of the applied energy, suggesting that for any pharmaceutical application, the choice of applied energy is critical to deposition profile of the aerosol.
Author Keywords: Author Keywords: Aerosol; Propylene glycol; Vaporization; Energy

Any thoughts or comments about the optimum e-cig wattage that would produce the fastest intake of nicotine? How might the "optimal" be proven?

 

[JW50]

Apparently I inadvertently posted this in two sub-forums. In the ask veterans sub-forum rolygate replied as follows:

Standard equipment operates around 4 watts, LR equipment is about 6 watts, and 5 volts produces 8 to 10 watts or so, depending on the exact resistance of the atty/carto used. It is generally accepted that increasing the power (wattage) increases the vapor volume and density, among other things. The liquid is used up faster as well.

Logically, this means there is more of everything in the vapor, including nicotine. Particle size may well be affected but this probably does not have as great an effect as the amount of nicotine supplied, which will most likely be more at higher wattages (it certainly feels that way).

However you also might need to take into account that nicotine is absorbed in the mouth, lungs and nose - not just the lungs. Probably, particle size is irrelevant in the mouth. There is a theory that more nicotine is absorbed in the mouth when vaping because the particle size in vapor is around ten times that of smoke, therefore vapor ingredients (such as nicotine) are not nearly as well absorbed, since the vapor does not penetrate the smallest airways of the lungs. Research that describes this is not easy to find, and it is extremely unlikely that an expansion of the research quoted above, that addresses the exact amount of power supplied to atomizer coils for any given result, will be forthcoming any time soon. This type of research is paid for by pharma and they don't have any reason to do it. The cheapest possible trials of this sort would cost several hundred thousand dollars.

Increase the power of your e-cig and you get more of everything. Nicotine is almost certainly absorbed by the mouth and nose as well as the lungs, so an optimal absorption method would be to hold the vapor in the mouth first, then inhale, then exhale through the nose. In the end, vaping time is probably the most easily adjusted factor, as 6 minutes at 8 watts may be equal to 12 minutes at 4 watts, whatever way you cut it.

That thread was closed. Although I don't necessarily disagree with rolygate, I don't necessarily agree either. Contrary to what rolygate says here, I think the New Zealand study said the "particles" were too small as compared to cigarette smoke to create the rapid effect of cigarettes. But, whatever the case, I think what perhaps many vapers find lacking is that "rapid" effect. To me, what the article suggests is that the energy input at the atty has an effect on particle size that in turn might effect where that particle impacts and causes effect, which in turn might effect how rapid "we feel it". Perhaps just out of past habit I'm personally looking for something like is experienced with cigarettes. Hence, the question.

Now, it is true that to obtain time related plasma concentration of nic, for a meaningful sample size, lots of dollars would likely be involved. But it occurs to me that blood plasma concentration may or may not tell us "are we feeling it". Really what we would like to know is what's hitting our mind - and we care less about blood - as long as the mind effect is right. Perhaps there are brain scans or similar type tests that could evidence "are we getting it" but still, it is we who are the real judge of "are we getting it". So, my thoughts were that maybe those who know the watts that gets them closest to "are we getting it", might enlighten all of us as to what watts are right. For those who have tried (and know what they have tried in terms of watts), your advise, information and experiences are sought. What is the best wattage to taking us to - "we are getting it".

 

[JW50]

One more brief comment. Particle size is very likely not the whole story. What kind of nic (and perhaps other ingredients) is there at the beginning of the process probably has much to do with it as well. But, keeping what is being vaped constant, what wattage takes us closer to "getting it"?

 

[4mehealth]

I (as nicely as possible) think you're looking at this the wrong way.

The ejuice is not being "atomized" as an aerosol (my interpretation is an aerosol is a liquid in fine particle form - loose translation). However, my thinking is the the ejuice in the atty is being "vaporized" (boiled). So you aren't actually inhaling any aerosol (like a puffer for asthmatics). You are inhaling a gas.

I may be wrong. I have no information to back myself up on this. Just my impressions.

As for "proper" wattage, I think it's an end user issue. You are now more able to tailor the vape to your liking. Like it cool, go on ahead. Want it warmer, change the settings. And everything in between. There is no umbrella perfect vape. What I like most likely will be very different than what you like.

 

[JW50]

I (as nicely as possible) think you're looking at this the wrong way.

The ejuice is not being "atomized" as an aerosol (my interpretation is an aerosol is a liquid in fine particle form - loose translation). However, my thinking is the the ejuice in the atty is being "vaporized" (boiled). So you aren't actually inhaling any aerosol (like a puffer for asthmatics). You are inhaling a gas.

I may be wrong. I have no information to back myself up on this. Just my impressions.

As for "proper" wattage, I think it's an end user issue. You are now more able to tailor the vape to your liking. Like it cool, go on ahead. Want it warmer, change the settings. And everything in between. There is no umbrella perfect vape. What I like most likely will be very different than what you like.

Perhaps you are right. But I tend to think "getting it" is a combination of things. I tend to agree with you that there is "vaporization" taking place. But lot at boiling temperatures. If it were coming to our mouth as vapor it would burn the bejeepers out of us. After vaporization it is cooling (and condensing back to liquid). We, I think, are getting a mist in our mouth and perhaps lungs if inhaled. The idea on the wattage is that it effects particle size that impacts where it goes on draw and inhale.

 

[JW50]

"But lot at boiling temperature" above should be "But look at boiling temperatures.

 

[4mehealth]

Well, I dunno then?

I found my vape in a 3.7v mod with LR atty's. I'm very happy with vaping now.

I mean, if you're looking for something similar to analogs, go with 6v? It'll be warmer for you.

As for simulating smoking, I don't think you'll ever get there. Smoking is smoking. Vaping is vaping. 2 different animals. They're similar, but they'll never be same. (I don't mean to sound short if it comes across that way).

As I said, everybody's different. With smoking, you're more or less stuck. Leaf burns, you inhale. 1 temp, very little difference in flavor, etc. Vaping provides you with a smorgasborg (sp) of options. Warm to cool vape, tobacco to marshmallow flavor. There's just too many combinations to be able to have somebody come here and tell you what's right for you.

Unfortunately, you have to find your way (trial and error). Once you get it though, it all falls into place. I'd suggest you not think of this as a true replacement of analogs. This is the evolution of smoking. Therefore, you can let go of vaping having to be just like smoking. Let go of your prejudices (meant in the nicest way possible), open your mind to vaping and enjoy it for what it is.

[/soapbox].

Good luck to you.