$regex = "/<[^>]+>\s(.*)\s+(?=<[^>]+pt10 pb5">)/i";
$str = "</div>
Quick and delicious appetizer with mince and bread for your feast menu. You can serve these mouth watering strips as a snack with noon tea.
<div class="pt10 pb5">";
tested on regex101 and regexr and working fine on both but not with php functions and I also tried to find any character that I need to escape but not found anything. thanx in advance for help