Hi Ravneet,
Was this a standalone question or in the context of the passage?
Real life is messy and it can be hard to predict which drugs will diffuse across.
There is no set cutoff for the size of the molecule, I mostly look if it is under 500 kDa and has less than 5 H bonds.
I would say it's a tough toss up between receptor mediated endocytosis and diffusion through the membrane.
However, assuming you were given the structure of Sotrastaurin, it is quite nonpolar (not a lot of N-H and O-H bonds, many aromatic rings etc). This makes it pretty feasible for it to diffuse
Receptor mediated endocytosis is tempting to say, but you'd have to assume that a receptor recognizes this kind of weird looking structure. It doesn't really look like any biological molecule, so perhaps it wouldn't be uptaken that way.
That being said, I'm not sure if many people (or if I) would have gotten this question without prompting.
I hope this helps!
Katt