US Pharm. 2014;39(12):72-73.
Method of Preparation: Note—This formula prepares either ranitidine HCl 15 mg/mL or cimetidine 60 mg/mL.
Calculate the quantity of each ingredient for the amount to be prepared. Accurately weigh or measure each ingredient. Mix the active drug, stevia, and acesulfame potassium with about 30 mL of Ora-Plus (or a similar suspending vehicle). Add the flavor and additional Ora-Plus (or similar suspending vehicle) to final volume, and mix well.
Use: This preparation has been used in the treatment of heartburn or irritation of the esophagus caused by gastroesophageal reflux disease.
Packaging: Package in tight, light-resistant containers. Shake well before taking.
Labeling: Keep out of reach of children. Discard after ____ [time period].
Stability: A beyond-use date of 2 weeks when stored in a refrigerator may be used for this preparation.1
Quality Control: Quality-control assessment can include weight/volume, pH, specific gravity, active drug assay, color, rheologic properties/pourability, physical observation, and physical stability (discoloration, foreign materials, gas formation, mold growth).2
Discussion: Although manufactured oral liquid drug products of ranitidine and cimetidine are available, they may contain alcohol. Alcohol is not an ingredient of choice in the treatment of heartburn or irritation of the esophagus caused by gastroesophageal reflux disease. Therefore, a formulation without alcohol may be advisable. Such a formulation can be prescribed and compounded on an individual basis.
Alternative vehicles may be used for this formulation. For example, different syrup and solution vehicles may be substituted for the sweetened and flavored vehicle presented here. Other compounding vehicles are available from different companies and can easily be used in this formulation. The advantage of the vehicle listed here is that the selection of the flavor can be individualized to the patient. Additionally, it may be necessary to adjust the concentration of the stevia in order to overcome any undesired taste of the drug. The concentration of the specific active ingredient can also be easily changed, depending upon the prescription received from the prescriber. In the event that a liquid dosage form does not work for the specific patient, other dosage forms, including troches and lozenges, may be prepared instead.
Ranitidine HCl (Zantac, C13H22N4O3S.HCl, MW 350.86) occurs as a white to pale yellow, crystalline, practically odorless powder. It is sensitive to light and moisture, and it melts at about 140°C with decomposition. Ranitidine is highly soluble in water and sparingly soluble in alcohol. Ranitidine contains not more than 0.75% of its weight upon drying, and the pH of a 1-in-100 aqueous solution is between 4.5 and 6.0.1
Cimetidine (Tagamet, C10H16N6S, MW 252.34) occurs as a white to off-white, crystalline powder that is odorless or may have a slight mercaptan odor. Cimetidine is soluble in alcohol and in polyethylene glycol 400, sparingly soluble in isopropyl alcohol, and slightly soluble in water. It melts between 139°C and 144°C and loses not more than 1.0% of its weight upon drying.1
Stevia (honey leaf, yerba dulce) powder is a relatively new sweetening agent that is extracted from the leaves of the Stevia rebaudiana Bertoni plant. Natural, nontoxic, and safe, it occurs as a white, crystalline, hygroscopic powder. Stevia can be used in both hot and cold preparations.3
Acesulfame potassium (C4H4NO4SK, MW 201.24) occurs as a white, crystalline powder or as colorless crystals. It is soluble in water and very slightly soluble in acetone and in alcohol. Acesulfame potassium is used as a sweetening agent.1
Ora-Plus is an oral suspending vehicle that accepts dilution of up to 50% or more with water, flavoring agents, or syrups and still retains its suspending properties. It has a pH of approximately 4.2 and an osmolality of about 230 mOsm/kg. Ora-Plus is a thixotropic vehicle with a viscosity of approximately 1,000 cps at 25°C. It contains purified water, microcrystalline cellulose, sodium carboxymethylcellulose, xanthan gum, carrageenan, sodium phosphate, and citric acid as buffering agents, simethicone as an antifoaming agent, and potassium sorbate and methylparaben as preservatives.4
REFERENCES
1. U.S. Pharmacopeia 37/National Formulary 32. Rockville, MD: U.S. Pharmacopeial Convention, Inc; 2014:403-453,1477,1489,1523,4538.
2. Allen LV Jr. Standard operating procedure for performing physical quality assessment of oral and topical liquids. IJPC. 1999;3:146-147.
3. Reynolds JE, ed. Martindale: The Extra Pharmacopoeia. 30th ed. London, England: Pharmaceutical Press; 1993:1049.
4. Ora-Plus product information. Allegan, MI: Perrigo; 2013.
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