US Pharm. 2023;48(1):59-60.
Method of Preparation: Calculate the required quantity of each ingredient for the total amount to be prepared. Accurately weigh and/or measure each ingredient. Place the required number of tablets in a suitable mortar, and comminute to a fine powder. Add the Ora-Blend in small portions, and triturate to make a smooth paste. Add increasing volumes of the Ora-Blend to make a lamotrigine liquid that is pourable. Transfer the contents of the mortar, stepwise and quantitatively, to a calibrated bottle. Add enough of the Ora-Blend to bring to final volume, and mix well. Package and label.
Use: This formulation, which is an official USP preparation, is used in the treatment of epilepsy.
Packaging: Package in tight, light-resistant containers.
Labeling: Keep out of reach of children. Discard after ____ [time period]. Shake well before use.
Stability: A beyond-use date of up to 90 days may be used for this preparation when it is stored at controlled room temperature or refrigerated temperature.1
Quality Control: Quality-control assessment can include weight/volume, pH (range: 4.0-5.0), specific gravity, active drug assay, color, physical observation, physical stability (discoloration, foreign materials, gas formation, mold growth), and preservative-effectiveness test.2,3
Discussion: This is an official USP preparation utilized in the treatment of epilepsy.1 Its stability in similar vehicles has been reported.4
Lamotrigine (Lamictal, C9H7Cl2N5, MW 256.09) occurs as a white to pale cream-colored powder that is slightly soluble in water. Lamotrigine is an anticonvulsant medication that is used for the treatment of epilepsy as well as for the treatment of bipolar disorder (a mental-health condition characterized by episodes of mood swings ranging from depression to abnormally elevated mood). In epilepsy, lamotrigine is used to treat focal seizures, tonic-clonic seizures, and seizures in Lennox-Gastaut syndrome. In bipolar disorder, lamotrigine is used to treat acute episodes of depression, manage rapid cycling (four or more episodes in a 1-year period) in bipolar II disorder, and prevent recurrence in bipolar I disorder. Lamotrigine was first marketed in the United Kingdom in 1991, and it was approved by the FDA for use in the United States in 1994. Lamotrigine is on the World Health Organization’s Model List of Essential Medicines, which includes what are deemed to be the safest, most effective medications that meet a healthcare system’s most important needs.5
Ora-Blend is a sweetened oral suspending vehicle that is used to simplify the process involved in the extemporaneous compounding of oral suspensions. Ora-Blend 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. Ora-Blend 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; includes simethicone as an antifoaming agent; and is preserved with methylparaben and potassium sorbate.6
REFERENCES
1. U.S. Pharmacopeia/National Formulary [current revision]. Rockville, MD: U.S. Pharmacopeial Convention, Inc; December 2022.
2. Allen LV Jr. Summary of quality-control testing for sterile and nonsterile compounded preparations, part 1: physical and chemical testing. IJPC. 2019;23(3):211-216.
3. Allen LV Jr. Summary of quality-control testing for sterile and nonsterile compounded preparations, part 2: microbiological testing. IJPC. 2019;23(4):299-303.
4. Nahata MC, Morosco RS, Hipple TF. Stability of lamotrigine in two extemporaneous oral suspensions at 4 and 25 °C. Am J Health Syst Pharm. 1999;56(3):240-242.
5. McEvoy GK, ed. AHFS Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists; 2005:2148-2154.
6. Ora-Blend product information. Minneapolis, MN: Perrigo; 2019.
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