<?php


$css="
    .class1{
        padding:10px 15px 0 auto;
        padding:10px 150px 0 20px;
        padding:13px 30px 10px 50px;
        padding:24px 1px 0 -20px;
    }
    ";

$parts = explode( "{", $css );
$parts = str_replace( "padding:" , "", explode( "}", $parts['1'] ) );
$padding = explode( ";", $parts['0'] );

print_r($padding);

?>

Array
(
    [0] => 
        10px 15px 0 auto
    [1] => 
        10px 150px 0 20px
    [2] => 
        13px 30px 10px 50px
    [3] => 
        24px 1px 0 -20px
    [4] => 
    
)