hello, please see this and other methods papers:

https://www.researchgate.net/publication/12236977_An_accurate_and_simple_method_for_measurement_of_paw_edema

http://link.springer.com/protocol/10.1385%2F1-59259-374-7%3A115

The kinetics is here:

http://link.springer.com/protocol/10.1385%2F1-59259-374-7%3A115

Article An accurate and simple method for measurement of paw edema

Usually Carraggeenan paw oedema lasts for about 24 hours with a maximal at about 6 hours., depending on the protocol/concentration used... The compound you select and it's treatment regime rely heavily on the pharmacokinetics and dynamics of the compound, and the route of administration. a compound if given  s.c or i.p is best given about 30 min prior to the carrageenan, but if it has a short halflife high clearance, then you may need to redose. If you give it orally, it depends on the Tmax, and when it is highest in plasma... usually give it some time prior to the carrageenan admin (i.e. 30min-2 hr prior)... but again, if it is rapidly cleared then it may seem in effective.... If given I.v it can be given sometime during the oedema, but that said it may not be effective anyway as it depends on the PK/PD properties. The carrageenan oedema can be very non-specific and many compounds can be ineffective in this model if they target specific pathways. Does this help?

Carrageenan paw oedema is usually difficult to revert particularly when the drug is given therapeutically. As my previous colleague said, it only last around 24 hours so a lot of people prefer to dose it before the carrageenan although how relevant is this sort of dosing would be a matter of discussion. Before you test any sort of drugs in any animal model you should ensure that the pathway you are trying to engage is relevant in the model. Otherwise you could be wasting your time and the animals as any results, positive or negative will be difficult to interpretate. I would start by using a COX-2 inhibitor as a comparator.