Usually, I suspend the compound in carbossimethylcellulose 1% p/v, if I have to made an oral administration.

Hi Lara! Thanks for sharing information. Are you using same salt of lapatinib i.e Di-p-Toluenesulfonate and does it dissolves nicely or still it is a suspension? and what is the solubility (range 5-10 mg/ml). I am trying to dissolve it in 0.5% Hypromellose (Hydroxypropylmethylcellulose) and 0.1! Polysorbate 80 as is mentioned in some papers but i am not able to get a uniform suspension.

I don't use lapatinib or its derivatives, but usually in cellulose I obtain a suspension. In order to uniform your suspension, you can try to sonicate.

I use 30% Captisol and sonicate and vortex. It does not make a solution at any dose I have used but you can get a fairly uniform suspension with the sonicating and vortexing.

Thanks Karyn! Can i make initial stock in DMSO and then dilute in 0.5% Hypromellose (Hydroxypropylmethylcellulose) and 0.1% Polysorbate 80 vehicle for animal use?

Sure you can. I don't know what kind of suspension that will make, but most things can be formulated with patience and sometimes a little heat or pH adjustment coupled with the sonication. The DMSO can have some side effects when dosed repeatedly so do watch for that and try to keep the final percentage low.

We were advised to prepare lapatinib fresh from the powder daily for in vivo use! Seems to be too much trouble... Did anyone have problem storing DMSO stock of lapatinib and using it to prepare suspension with 0.5% Hypromelose daily?