unlike vs different from

I want to explain the thing like "The thing is dissimilar to the other one explained before".
See the thread discussed here, I can summarize as follows:
(1) Drug B is unlike Drug A, in that Drug B can also be administered orally.
(2) Drug B is different from Drug A, in that Drug B can also be administered orally.
(3) Unlike Drug A, Drug B can also be administered orally.
(4) ??Different from Drug A, Drug B can also be administered orally.
Other phrases, like unlike, that can be used in (3) are as opposed to and contrary to. These, however, cannot be used in (1) and (2).