Put shaders in different AssetBundle without bundles dependency.

Sorry for bad english, it's not my mother tongue.

Situation:
In my project I'm packing prefabs in AssetBundles and then loading with WWW.

Dependencies looks like this:

Every prefab contains meshes, textures, shaders, etc. It's a whole GameObject.

It's made because on mobile devices loading and compiling custom shaders from AssetBundle take a LOT of time (about 6-8 seconds on Galaxy S1). But if all shaders placed in one AssetBundle it takes a lot of time once, not on every bundle with prefab when I want to load and instantiate them.

The problem appears, when I want to change something in one of my prefabs. I must rebuild all this bundles and user must download them all again. And again and again, every time I change something. It's really annoying.

Question:
Is there a possibility to remove this dependencies? Or make this dependencies works in my situation somehow? Or I must look in another direction and organize prefabs differently?

If something is unclear - please ask. I will try to explain.

Thanks in advance.

[1]: http://i.gyazo.com/6770e533501256e2fa9a1a6bbb323cf8.png