Duphalac is part of the medicine group called Laxatives used to treat acute constipation. The drug is a synthetic sugar, which improves bowel movements. Duphalac ® Solution offers relief from constipation for all the family. It is available in bottles of 200, 300, 500 and 1000 ml, so that you can choose the size that is most convenient for you. Duphalac ® can be taken as a single daily dose or divided into two doses. It comes with a handy measuring cup to help make sure you take the right amount. Try to take it at the same time every day for example during breakfast. Take Duphalac ® as a single daily dose or in two divided doses. After a ... What is DUPHALAC ®? Duphalac ® is an effective medicine for constipation that can be used by all the family. The active ingredient of Duphalac ® is lactulose, which helps to soften the consistency of stools so they are easier to pass. 4