Published May 15, 2015 COMPOUNDING Lamotrigine 1 mg/mL Oral Suspension Loyd V. Allen, Jr., PhDProfessor EmeritusCollege of Pharmacy, University of OklahomaOklahoma City US Pharm. 2015;40(5):64-65. Method of Preparation: Calculate the quantity of each ingredient for the amount to be prepared. Accurately weigh or measure each ingredient. Pulverize one lamotrigine 100 mg tablet to a fine powder. Add a few mL of Ora-Plus and mix to form a smooth paste. Add additional Ora-Plus geometrically and mix well. Add sufficient Ora-Sweet or Ora-Sweet SF to final volume and mix well. Package and label. Note—With Ora-Plus, Ora-Sweet, and Ora-Sweet SF preparations, Ora-Blend or Ora-Blend SF may also be used as the vehicle. Use: This preparation has been used as an anticonvulsant. Packaging: Package in tight, light-resistant containers. Shake well. Keep out of the reach of children. Labeling: Keep out of the reach of children. Discard after ____ [time period]. Stability: A beyond-use date of up to 91 days may be used for this preparation.1,2 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).3 Discussion: Lamotrigine (Lamictal, C9H7Cl2N5, MW 256.09) occurs as a white to pale cream-colored powder that is slightly soluble in water.1 Lamotrigine is used as an anticonvulsant and in the treatment of bipolar disorder. It is available in tablet form in strengths of 25 mg, 100 mg, 150 mg, and 200 mg. Each tablet also contains the inactive ingredients lactose monohydrate, magnesium stearate, microcrystalline cellulose, and sodium starch glycolate. Ora-Plus is an oral suspending vehicle that accepts dilution of up to 50% or more with water, flavoring agents, or syrups while still retaining its suspending properties. It has a pH of approximately 4.2 and an osmolality of about 230 mOsm/kg. 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.4 Ora-Sweet syrup vehicle is a flavoring vehicle for oral extemporaneous preparations. It is flavored with a citrus-berry flavor blend and contains glycerin and sorbitol to prevent cap lock, a problem associated with many syrups. Ora-Sweet is buffered to a pH of approximately 4.2 and has an osmolality of about 3,240 mOsm/kg. It contains purified water, sucrose, glycerin, sorbitol (5%), flavoring, sodium phosphate, and citric acid as buffering agents, as well as potassium sorbate and methylparaben as preservatives.5 Ora-Sweet SF sugar-free syrup vehicle is a flavoring vehicle for oral extemporaneous preparations. 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. It will tolerate a dilution to 50% with dissolved actives in water or suspending agents while still retaining an acceptable taste. Ora-Sweet SF has an osmolality of 2,150 mOsm/kg. It 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.6 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 vehicle that is buffered to a slightly acidic pH of approximately 4.2 and an osmolality of 2,107 mOsm/kg. Ora-Blend occurs as an opaque, pinkish liquid with a sweet citrus-berry flavor. It contains purified water, sucrose, glycerin, sorbitol, flavoring, microcrystalline cellulose, carboxymethylcellulose sodium, xanthan gum, carrageenan, citric acid, and sodium phosphate as buffers and simethicone as an antifoaming agent. It is preserved with methylparaben and potassium sorbate.7 Ora-Blend SF is a flavored oral suspending vehicle used in the extemporaneous compounding of oral suspensions. It is an aqueous-based, sweetened vehicle consisting of a synergistic blend of suspending agents. It is buffered to a pH of approximately 4.2 and 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, carrageenan, citric acid, sodium saccharin, 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 38/National Formulary 33. Rockville, MD: U.S. Pharmacopeial Convention, Inc; 2014:559-611,1946.2. Nahata MC, Morosco RS, Hipple TF. Stability of lamotrigine in two extemporaneously prepared oral suspensions at 4 and 25°C. Am J Health Syst Pharm. 1999;56:240-242.3. 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.