When it is permissible to take medicine but it is packaged in plastic, paper, or cardboard, one may tear open the packaging in order to get to the medicine. Those who are stringent make sure to destroy the packaging, rendering it unusable for storing the medicine (above, 15:12). It is preferable to avoid tearing words on the packaging. Be-di’avad, if it cannot be opened without tearing words, it may still be opened, because one’s intention is not to erase the letters, and the “erasing” happens through a destructive action (as explained above, 18:3).
When one may take pills that are inside a sealed plastic container, he may remove the cover, even though doing so breaks the temporary plastic seal connecting the cover to the container. This is not considered making a kli, because the container and cover were already finished products; they were simply attached to the plastic seal (above 15:13-14).
