you have to have hash oil. the nonploar nature doesnt like to dissolve in water(blood), there are ways of getting around this of course.
i worked on a preparation using methylated cyclodextrins that would work. and while this can have implications in a hospital setting thats not really how the drug works. theres really no reason for an immediate dose as far as medical reasons
abstract
Cannabis is widely used recreationally and for symptomatic relief in a number of ailments. However, cannabis has been implicated as a risk factor for the development of psychotic illness. For forty years researchers have utilised intravenous preparations of Δ(9)-THC, as well as several other phytocannabinoids, in a laboratory setting. The intravenous route has the most reliable pharmacokinetics, reducing inter-individual variation in bioavailability and is well suited for the delivery of synthetic compounds containing a sole pharmacological moiety. Given the association between cannabinoids and psychotic illness, there has been a resurgence of interest in experimental studies of cannabinoids in humans, and the intravenous route has been employed. Here in a critical review, we appraise the major findings from recent intravenous cannabinoid studies in humans and trace the historical roots of this work back to the 1970's.
as you can see, its nothing new