See the question and my original answer on StackOverflow

I suggest you use the mono Cecil library. This is the basic example:

//Creates an AssemblyDefinition from the "MyLibrary.dll" assembly
AssemblyDefinition myLibrary = AssemblyFactory.GetAssembly ("MyLibrary.dll");

//Gets all types which are declared in the Main Module of "MyLibrary.dll"
foreach (TypeDefinition type in myLibrary.MainModule.Types) {
    //Writes the full name of a type
    Console.WriteLine (type.FullName);

This will not load all the dependencies.