Purple Wockhardt Cough Syrup Wockhardt Cough Syrup. The recommended dose of Promethazine HCl Syrup is 25 mg. Each bottle contains 10 mg/5 ml of codeine phosphate and 6.25 ml/5 ml of promethazine hydrochloride. Ingredients of cough syrup when mixed with flavoring ingredients make their transition to lean. when they are. Ingredients often include sugary soft drinks and...