To Study the mode of administration of drug in experimental animals

Theory 

Intraperitonial

In this technique animal is held as discussed before and skin is picked up by fingers, needle is inserted in the skin first, just by piercing still more, drug is injected by ensuring needle is not in muscle layers or near nerves. 

Oral

Introduce needle in mouth and push piston to force drug orally.

Oral Needle

Rabbit marginal vein technique

The lateral margin of the ear is shared and swabbed with disinfected. The ear is grasped between the thumb and index finger in a well restrained animal and using a 20 gauge needle with the bevel up, the vein puncture is made at a site immediately above index finger along the marginal vein. Very gentle aspiration must be applied in order to avoid collapse of vein.  

Animal / needle size	IV	IP	SC	IM	Oral
Rat		25G	25G	25G
Mouse	27G	25G	25G	25G	18G / 26 no.
Rabbit	25G	21G	25G	25G	Catheter No. 9
Guinea		25G	25G	25G

Maximum volume of drug solution to be given to animals

Animal	Intravenous	Intramuscular	Intraperitoneal	Subcutaneous	Oral
Mouse	0.5	0.05	1	0.5-1	1
Rat	1	0.1	2-5	2-5	5
Guinea pig	1	0.25	2-5	5	10
Rabbit	5-10	0.5	10-20	5-10	20
Dog	10-20	5	20-50	10	100