Duphapen+Strep Presentation A sterile white aqueous suspension for injection. Each ml contains: Procaine Benzylpenicillin (procaine penicillin) 200 mg Dihydrostreptomycin-Sulphate 250 mg The product also contains nipasept sodium as antimicrobial preservative and sodium formaldehyde sulphoxylate dihydrate as antioxidant.