dont use concentrates myself so no experience
but i saw this
Germany legalised medical cannabis recently (few months)
this is from storz and bickel medical site for volcano medic
seems alcohol tincture is ok if alcohol is first evaporated away with low heat
Dronabinol
In Germany ∆9-THC (dronabinol) is produced by THC-Pharm and Bionorica Ethics in a partly synthetic manner or directly from hemp flowers. The extracted pure substance is used as a formula magistralis for pharmacies in Germany that manufacture capsules or liquids dissolved in neutral oil or alcohol for oral application. The dronabinol dissolved in alcohol is also appropriate for vaporization and subsequent inhalative application.
Alcoholic solution
Use only approved dronabinol (THC) as it is manufactured as a formula magistralis from pharmacies. ∆9-THC (dronabinol) is a colorless, odorless and odor-free substance of honey-like viscosity.The pharmacy produces an alcohol solution according to your physician's prescription (generally 2.5% THC) for inhalation with the VOLCANO MEDIC Vaporization System.
Dronabinol (THC) dissolved in oil is not suitable for vaporization and is intended for oral administration.
and
Cannabis extracts and pure cannabinoids - dissolved in alcohol - need a substrate to be vaporized. Therefore a liquid pad made of stainless steel wire was developed, fitting perfectly into the filling chamber. The wire of the liquid pad has a surface area of approx. 100 cm² that is sufficient for vaporization. The liquid pad can absorb up to 20 drops of alcoholic solution without any problems.
As the alcoholic fraction is not supposed to be inhaled a separation is necessary and can be executed easily. The filling chamber with the liquid pad is placed on the hot air generator and air with a temperature up to 100°C is pumped through the liquid pad. In this temperature range, the cannabinoids do not vaporize, but the alcohol evaporates quickly. After the alcohol has vaporized, which, because of the alcohol's distinctive odor, can easily be determined by an olfactory test, the 'AIR' is turned off and the device is heated to 210°C. The cannabinoids will now be vaporized from the liquid pad and subsequently be inhaled. Dronabinol has neither odor nor taste and it can be easily vaporized at higher temperatures.
link
http://www.vapormed.com/shop_eu/en/dronabinol/