Drug maker Lupin on Thursday said it has received approval from the US health regulator to market a generic medication, used before a surgery to decrease the volume of secretions from mouth, lungs and stomach, in the American market. The company has received approval from the US Food and Drug Administration (USFDA) for Glycopyrrolate Injection, a generic equivalent of Hikma Pharmaceuticals' Robinul Injection, the Mumbai-based drug maker said in a statement.