Gastren Duo Suspension is a 100ml pharmaceutical product from Pharmactive containing calcium carbonate, magnesium carbonate, and sodium alginate. This medication is formulated as an oral suspension for gastrointestinal conditions. The active ingredients in this suspension are calcium carbonate, magnesium carbonate, and sodium alginate. The product comes in a 100ml bottle. As this is a medication, please consult your healthcare provider for proper usage instructions, dosage, and potential side effects.