Is it illegal to compound commercially available products?

At a pharmacy I worked at they compound omeprazole 2mg/ml by mixing 24 capsules of the 20mg omeprazole capsules + 1 tsp baking soda, 240 mL water. I was told this is the only method Medicaid would pay for this disabled child who gets it twice a month. Another pharmacist then refused to make it saying it's illegal to compound because a commercially available product, First Omeprazole, is available. I'm really not sure. They have been compounding it twice a week for years (well before I ever... Is it illegal to compound commercially available products?
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Source Type: forums