Veya,

$a="[11::40],[11::41],[11::42],[11::43],[11::44],[11::45],";
preg_match_all('#::(.*?)]#si',$a,$b);
print_r($b[1]);

Çıktı:

Array
(
[0] => 40
[1] => 41
[2] => 42
[3] => 43
[4] => 44
[5] => 45
)