hello and welcome,
do you have the habit of tobacco/pan chewing?then the patch may be related to any precancerous lesions like leukoplakia
or oral submucous fibrosis
are the preferred drug in such cases.
if this is not the cause,then it may be aphthous ulcer type.
it can be treated by tab.flanzen and tab.wysalone.
avoid intake of spicy and sour food like mixture etc.
maintain good oral hygiene
avoid harsh brushing techniques.