For those interested, found the formulation: Phenergan Gel Question: We have a prescription for Phenergan gel 12.5 mg/0.1 cc and we can't find any information about how to formulate this product or whether it is commercially available. Any help that you can provide for this formulation would be greatly appreciated. Answer: Promethazine has been available overseas as 2% cream for topical application. One reference describes the compounding of promethazine in hydroxypropylmethylcellulose gel. Promethazine HCl is soluble 1 in 0.6 of water, 1 in 9 of alcohol; a 10% solution in water has a pH of 5.0 to 6.0. it is incompatible with a number of chemicals, including morphine sulfate and alkalies. It would seem reasonable to combine promethazine HCl solution with a commercially-available gel base, such as KY, Surgilube, or Liqua-Gel, in the desired concentration, or with the poloxamer gel based on "Pluronic F-127NF." The final product should be stored in airtight containers and protected from light. P Prescott, MD