Can exist a best practice/way to load dynamic class at php?

Having a main class where any code has access, can some code similar, but with a best practice to load dynamic class?

candidate code:

static public function __callStatic($mtd,$arg){

    // using spl_autoload_register()
    $class = '\\framework\\libs\\'.$mtd;  

    $inst = new $class($arg);

}

syntax:

main::dinamicu($data);