What pill is purple and white capsul with r 158 and its 20mg?

Pill imprint Omeprazole 20mg R158 has been identified as Omeprazole delayed release 20 mg.

Omeprazole is used in the treatment of gerd; stomach ulcer; indigestion; erosive esophagitis; helicobacter pylori infection (and more), and belongs to the drug class proton pump inhibitors. Risk cannot be ruled out during pregnancy.

You could view the pill on: https://www.drugs.com/imprints/omeprazole-20mg-r158-13447.html

Take care, best wishes!