Promethazine Hcl Syrup 100 ml is anti-allergic formulation which is intended to be used for treatment of various allergic symptoms, nausea, & trouble sleeping. It belongs to first generation antihistamine class of medication and assures targeted mode of action. Active compound present in this syrup has chemical formula C17H20N2S with molecular weight of 284.42 g/mol. It works by blocking histamine H-1 receptor activity for providing relief from allergic conditions. Promethazine Hcl Syrup 100 ml has excellent bioavailability of about 88% with 93% of protein binding ability. It gets metabolized in liver by glucuronidation & sulfoxidation with elimination half life of 16 to 19 hours.