gistfile1.as

package com.illuzor.test {
	
	import flash.display.Loader;
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.net.URLRequest;
	
	public class Main extends Sprite {
		
		public function Main():void {
			var loader:Loader = new Loader();
			loader.load(new URLRequest("TestToLoad.swf"));
			loader.contentLoaderInfo.addEventListener(Event.COMPLETE, onLoaded);
		}
		
		private function onLoaded(e:Event):void {
			e.target.removeEventListener(Event.COMPLETE, onLoaded);

			var TestClass:Class = e.target.applicationDomain.getDefinition("com.illuzor.test.LoadedClass") as Class;
			var loadedClassInstance:ITest = new TestClass() as ITest;
			
			trace(loadedClassInstance.getTestNumber());
			trace(loadedClassInstance.getTestText());
			trace(loadedClassInstance.testGetterVar);
		}
		
	}
}

package com.illuzor.test {

	public interface ITest {
		function getTestText():String;
		function getTestNumber():Number;
		function get testGetterVar():String;
	}
	
}