Pentobarbital individual efects for tthe body fat, and the dosage

Hello,

I'm a pharmacy student in my country, and we were making rat experiments with pentobarbital about individual variation for one dose, and efects of modifications in interval dosification.

So, I need to know about individual efects of pentobarbital in: man vs.woman, and level of fat porcentage(%). I mean I would like to know about the distribution of pentobarbital in the body, espetially in the fat, and it's relation with the efects, could you show me or send me some informations or investigations, about it? , thank you very much.