Quinidine Sulfate 10 mg/mL Oral Suspension

US Pharm.2015;40(2):62-63.

Method of Preparation: Calculate the quantity of each ingredient for the amount to be prepared. Accurately weigh or measure each ingredient. Crush the tablets to a fine powder or use the quinidine sulfate powder. Add about 25 mL of Ora-Plus, and mix to form a smooth paste. Add the remaining Ora-Plus and mix well. In portions, add the Ora-Sweet or the Ora-Sweet SF, with thorough mixing between each addition, until the final volume is obtained. (Alternatively, Ora-Blend or Ora-Blend-SF could be used instead for this formulation.) Package and label.

Use: This preparation has been used as an antiarrhythmic agent for patients who cannot swallow solid dosage forms.

Packaging: Package in tight, light-resistant containers.

Labeling: Keep out of reach of children. Discard after ____ [time period]. Shake well before taking.

Stability: A beyond-use date of up to 60 days when stored at room temperature or in a refrigerator may be used for this preparation.^1,2

Quality Control: Quality-control assessment can include weight/volume, pH, specific gravity, active drug assay, color, rheological properties/pourability, physical observation, and physical stability (discoloration, foreign materials, gas formation, mold growth).³

Discussion: Quinidine sulfate ([C₂₀H₂₄N₂O₂]₂.H₂SO₄.2H₂O, MW 782.94) occurs as fine, needlelike, white crystals frequently cohering in masses or as a fine, white powder. It is odorless and darkens on exposure to light. Solutions are neutral or alkaline to litmus. Quinidine sulfate is soluble in alcohol and slightly soluble in water. The oral suspension USP contains 90.0% to 110.0% of the labeled amount of quinidine sulfate (C₂₀H₂₄N₂O₂)₂.H₂SO₄.2H₂O. The pH of the preparation is 3.4 to 4.4.¹

Ora-Plus 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. 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.⁴

Ora-Sweet contains purified water, sucrose, glycerin, sorbitol (5%), flavoring, sodium phosphate, and citric acid as buffering agents and potassium sorbate and methylparaben as preservatives. It is buffered to a pH of approximately 4.2 and has an osmolality of about 3,240 mOsm/kg.⁵

Ora-Sweet SF contains water, sodium saccharin, xanthan gum, glycerin, sorbitol, citric acid, and sodium citrate as buffers; methylparaben, propylparaben, and potassium sorbate as preservatives; and flavoring agents. It is a sugar-free, alcohol-free syrup flavored with a citrus-berry flavor blend. Ora-Sweet SF is buffered to a pH of approximately 4.2, and it may be used alone or in combination with other vehicles. Ora-Sweet SF will tolerate a dilution to 50% with dissolved actives in water or suspending agents and still retain an acceptable taste. It has an osmolality of 2,150 mOsm/kg.⁶

Ora-Blend is a sweetened oral suspending vehicle that is used to simplify the process involved in the extemporaneous compounding of oral suspensions. It is an aqueous-based, sweetened vehicle buffered to a slightly acidic pH of approximately 4.2. Ora-Blend 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, flavoring, microcrystalline cellulose, carboxymethylcellulose sodium, xanthan gum, carrageenan, citric acid, and sodium phosphate as buffers; simethicone as an antifoaming agent; and methylparaben and potassium sorbate as preservatives.⁷

Ora-Blend SF is a flavored oral suspension vehicle consisting of a synergistic blend of suspending agents with a high degree of colloidal activity. It is buffered to a pH of about 4.2, has a viscosity of approximately 1,000 cps at 25°C, and has an osmolality of 1,073 mOsm/kg. Ora-Blend SF occurs as an opaque, pinkish liquid with a sweet citrus-berry flavor. It contains purified water, sorbitol, glycerin, flavoring, microcrystalline cellulose, carboxymethylcellulose sodium, xanthan gum, and carrageenan, as well as sodium saccharin, citric acid, and sodium citrate as buffers and simethicone as an antifoaming agent. It is preserved with methylparaben, propylparaben, and potassium sorbate.⁸

REFERENCES

1. U.S. Pharmacopeia 36/National Formulary 31. Rockville, MD: U.S. Pharmacopeial Convention, Inc; 2013:335-398,1523,4519.
2. Allen LV Jr, Erickson MA. Stability of bethanechol chloride, pyrazinamide, quinidine sulfate, rifampin, and tetracycline hydrochloride in extemporaneously compounded oral liquids. Am J Health Syst Pharm. 1998;55:1804-1809.
3. Allen LV Jr. Standard operating procedure for performing physical quality assessment of oral and topical liquids. IJPC. 1999;3:146-147.
4. Ora-Plus product information. Allegan, MI: Perrigo; 2014.
5. Ora-Sweet product information. Allegan, MI: Perrigo; 2014.
6. Ora-Sweet SF product information. Allegan, MI: Perrigo; 2014.
7. Ora-Blend product information. Allegan, MI: Perrigo; 2014.
8. Ora-Blend SF product information. Allegan, MI: Perrigo; 2014.

To comment on this article, contact rdavidson@uspharmacist.com.