would really appreciate any input on the intranasal instillation as well.

Hi Ruiying,

If you have instrumented the airway correctly there should be ZERO in the digestive tract. Depending on who or what you are intubating it should be obvious pretty quick that you have sent the endotracheal tube down the oesophagus.

Assuming that you have done it correctly - for ~500g Sprague Dalwey's and a 12G cannula, you can expect approx 85%+ of the dose to be delivered to the lungs. The remaining ~15% is left in the syringe and tube.

Have a look at the following publication where we quantified that:

Article Optimized Aerosol Delivery to a Mechanically Ventilated Rodent

If you are speaking to intranasal aspiration, the distribution of drug will be dependent on subject type, droplet volume, surface tension and viscosity of the drug, breathing rate and tidal volume of the subject. Smaller animals, e.g. mice will definately see deposition in the lung, but you will see more in the nasal passages, oseophagus and stomach. I am afraid I have nothing to share on that.

If you are delivering to larger animals, e.g. pig....using the a nasal spray, you will see close to ZERO in the lung and most in the oesophagus again......Have a look here:

Article Distinct immune responses and virus shedding in pigs followi...

Considering both publications referenced above, targeting the only will require proper intubation. Targeting the lung but not minding some deposition elsewhere can be achieved using aerosol.

Also..........please consider what the final therapy will be, and how it will be administered.....i.e. don't develop everything using one method of administration and then change that when you move to larger animals/humans......depending on what your therapeutic is, location of deposition may lead to significant differences in clinical response.

Finally, if you need to find out what the distribution is in your hands (different labs = different results), I suggest you follow the relatively simple protocol described in the top paper; Article Optimized Aerosol Delivery to a Mechanically Ventilated Rodent

Hope that helps.

Ronan.