Rapid-onset intranasal delivery of anticonvulsants: pharmacokinetic and pharmacodynamic evaluation in rabbits.
http://www.ncbi.nlm.nih.gov/pubmed/1...ubmed_RVDocSum
In order to assess the feasibility of this approach for the emergency treatment of status epilepticus, three anticovulsants, i.e. diazepam (DZ), clonazepam (CZ), and a monocarbamate-based new compound (MCA) were studied in rabbits for the pharmacokinetics (PK) and pharmacodynamic (PD) response following intravenous (IV) and IN administrations.
The animals were intranasally dosed with DZ (1 mg/kg), CZ (0.2 mg/kg), and MCA (5 mg/kg), dissolved in 200 microl of vehicle consisting of propylene glycol (PG), ethanol (EtOH), and water in the presence or absence of 1% sodium glycocholate (SGC) using single and repeated dosing schedules.
Both DZ and CZ were absorbed very rapidly from 1% SGC/60% PG-30% EtOH-10% Water after IN single application; the T(max)'s were less than 2 min. The absorption rate of MCA was relatively slower with the peak time of 13-32 min. The bioavailability of single IN administration for DZ, CZ, and MCA determined over the first 2 or 4 h was found to be 77, 45, and 79%, respectively.
The peak plasma level of DZ(valium) increased linearly with increasing the volume fraction of EtOH in the ternary cosolvent (20% to 60.
A repeated IN application of DZ, 5 min after the first dose, doubled the C(max) and AUC(0-2 h) values of the first one, whereas those of CZ and MCA resulted in an increase of 73-94% of the first dose. A single IN application of DZ- and CZ-containing formulations produced a PD response within 1.5 min, which was comparable to that of an IV injection. These results suggest that single or repeated IN applications of DZ, CZ, and MCA in a hydroalcohol-glycolic formulation might represent a viable approach to achieving a rapid systemic absorption of these anticonvulsants during the emergency treatment of status epilepticus and other types of seizures.
You have to remeber they used rabbits for this experiment, and the experiment used a solution of ethanol, water, and propyl glycol.
It mentions that increasing the amount of ethanol, when using valium, increased the absortion linearly. So, soluting your benzo in alcohol helps your nose absorb benzos, also, the lack of ethanol or suitable solvent leaves benzos un absorbed. So yea, when used in a solution, benzos can be taken nassally. They can be taken nasally but you may lose some umph
edit:
If I was going to sniff benzos, or was looking for a benzo 'rush' I would look at this part:
A single IN application of DZ- and CZ-containing formulations produced a PD response within 1.5 min, which was comparable to that of an
IV injection.
This was their 2nd dose. The first one just got the drug up there and the 2nd one was like an 'IV injection'. So, go sniff 2 bars, then make 10%ethanol/90% water in a rig or eyedropper. Then drop some of that down your nose.