How to make sure that the composite cache is not reset due to frequently changing meta tags in the html code of the page?

Question

1C-Bitrix

Hello.
There is a site on Bitrix with the included composite. With the following settings:



In the site template in the head.php file, the method for displaying keyword meta tags

<?$APPLICATION->ShowMeta("keywords")?>


On the index.php site page, I call the method for setting these keywords
$APPLICATION->SetPageProperty( "keywords", "online pharmacy, ".$dataCity['name']);
$dataCity['name'] - variable value changes

dynamically the value of $dataCity['name'] changes - often the composite cache is overwritten due to the changed html code of the page.
How to make it so that the composite cache would not be reset?

ps