US Pharm. 2015;12(40):52-53.
Method of Preparation: Calculate the quantity of each ingredient for the amount to be prepared. Accurately weigh or measure each ingredient or obtain the required number of lansoprazole 30 mg delayed-release capsules. Empty the capsules into a mortar or other suitable container. Crush the contents into a fine powder. Wet the powder with the sodium bicarbonate 8.4% solution and slowly add the remainder of the sodium bicarbonate solution; mix well. Add sufficient Ora-Blend vehicle to final volume and mix well. Package and label.
Use: This oral preparation is a pediatric dosage form of a proton pump inhibitor.
Packaging: Package in tight, light-resistant containers.
Labeling: Keep out of reach of children. Shake well. Discard after ____ [time period].
Stability: A beyond-use date of not more than 90 days when stored in a refrigerator or at controlled room temperature may be used.1
Quality Control: Quality-control assessment can include weight/volume, pH (8.0-8.5), specific gravity, active drug assay, color, rheologic properties/pourability, physical observation, and physical stability (discoloration, foreign materials, gas formation, mold growth).2
Discussion: Lansoprazole (Prevacid, MW 369.36, C16H14F3N3O2S) is a white to brownish-white powder that is practically insoluble in water and sparingly soluble in ethanol. It melts at about 166°C with decomposition. Lansoprazole is a proton pump inhibitor/gastric acid secretion inhibitor used orally for short-term treatment of active duodenal ulcers and for maintenance treatment of healed duodenal ulcers. It is also used in the short-term treatment of active benign gastric ulcer, the treatment of nonsteroidal anti-inflammatory drug–associated gastric ulcer, and the short-term treatment of all grades of erosive esophagitis, and to maintain healing of erosive esophagitis.
Lansoprazole is stable when exposed to light for up to 2 months; however, it decomposes in aqueous solutions, with the rate of decomposition increasing with decreasing pH. Its half-life in solution at room temperature is about 30 minutes at pH 5, but is about 18 hours at pH 7. Seven stability studies that used a variety of vehicles have been summarized.3
Sodium bicarbonate (baking soda, sal de Vichy, MW 84.01, NaHCO3) occurs as a white, crystalline powder that is stable in dry air but slowly decomposes in moist air. Its freshly prepared solutions are alkaline to litmus; a pH of 8.3 is typical for a freshly prepared 0.1 M aqueous solution at 25°C. Sodium bicarbonate is soluble in water (1 g in 10-12 mL), but it is insoluble in alcohol. When it is heated to about 50°C, an aqueous solution of sodium bicarbonate will decompose into carbon dioxide, sodium carbonate, and water. Even at ambient temperatures, aqueous solutions will decompose with partial conversion into carbonate. Aqueous solutions of sodium bicarbonate are best sterilized by filtration. If autoclaving is used, there is a specific procedure to ensure the solution’s stability, as follows: To minimize decomposition, carbon dioxide gas should be passed through the solution in its final container immediately prior to sealing. The solution is then autoclaved and not opened for at least 2 hours after it has returned to ambient temperature; this allows for complete reformation of the bicarbonate from the carbonate that is produced during the heating process. Sodium bicarbonate will react with acids, acidic salts, and many alkaloidal salts and will evolve carbon dioxide. Sodium bicarbonate should be preserved in well-closed containers.1,4,5
Ora-Blend is a sweetened oral suspending vehicle used to simplify the process involved in the extemporaneous compounding of oral suspensions. It is an aqueous-based, sweetened vehicle consisting of a synergistic blend of suspending agents that have a high degree of colloidal activity. Ora-Blend is buffered to a slightly acidic pH of approximately 4.2, and it has a viscosity of approximately 700 cps at 25°C and an osmolality of 2,107 mOsm/kg. It occurs as an opaque, pinkish liquid with a sweet citrus-berry flavor. Ora-Blend contains purified water, sucrose, glycerin, sorbitol, microcrystalline cellulose, flavoring, carboxymethylcellulose sodium, carrageenan, xanthan gum, citric acid, and sodium phosphate as buffers, simethicone as an antifoaming agent, and methylparaben and potassium sorbate as preservatives.6
REFERENCES
1. U.S. Pharmacopeia 38/National Formulary 33. Rockville, MD: U.S. Pharmacopeial Convention, Inc; 2014:559-611,1946.
2. Allen LV Jr. Standard operating procedure for performing physical quality assessment of oral and topical liquids. IJPC. 1999;3:146-147.
3. Trissel LA. Trissel’s Stability of Compounded Formulations. 5th ed. Washington, DC: American Pharmacists Association; 2012:279-280.
4. Cable CG. Sodium bicarbonate. In: Rowe RC, Sheskey PJ, Owen SC, eds. Handbook of Pharmaceutical Excipients. 6th ed. Washington, DC: American Pharmaceutical Association; 2009:629-633.
5. Reynolds JE, ed. Martindale: The Extra Pharmacopoeia. 30th ed. London, England: Pharmaceutical Press; 1993:851.
6. Ora-Blend product information. Allegan, MI: Perrigo; 2014.
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