Stability of extemporaneously prepared rufinamide oral suspensions.
BACKGROUND
Rufinamide is an oral antiepileptic drug indicated for adjunctive therapy in treating generalized seizures associated with Lennox-Gastaut syndrome. Currently, rufinamide is available as 200-mg and 400-mg tablets. A liquid dosage form does not exist at the present time. Lack of a suspension formulation may present an administration problem for many children and adults who are unable to swallow tablets. The availability of a liquid dosage form will provide an easy and accurate way to measure and administer the medication.


OBJECTIVE
To determine the stability of both sugar-containing and sugar-free rufinamide suspensions over a 90-day period.


METHODS
A suspension of rufinamide 40 mg/mL was prepared by grinding twelve 400-mg tablets of rufinamide tablets in a glass mortar. Sixty milliliters of Ora-Plus and 60 mL of either Ora-Sweet or Ora-Sweet SF (sugar free) were mixed and added to the powder to make a final volume of 120 mL. Three identical samples of each formulation were prepared and placed in 60-mL amber plastic bottles and were stored at room temperature. A 1-mL sample was withdrawn from each of the 6 bottles with a micropipette immediately after preparation and at 7, 14, 28, 56, and 90 days. After further dilution to an expected concentration of 0.4 mg/mL, the samples were assayed using high-performance liquid chromatography. Stability was defined as the retention of at least 90% of the initial concentration.


RESULTS
At least 90% of the initial rufinamide concentration remained throughout the 90-day study period in both preparations. There were no detectable changes in color, odor, taste, and pH and no visible microbial growth.


CONCLUSIONS
Extemporaneously compounded suspensions of rufinamide 40 mg/mL in a 1:1 mixture of Ora-Plus and Ora-Sweet or Ora-Sweet SF were stable for at least 90 days when stored in 59-mL amber polypropylene plastic bottles at room temperature.
Wegmans School of Pharmacy, St. John Fisher College, Rochester, NY 14618, USA. dhutchinson@sjfc.edu
David J
DJ
Hutchinson
Yayin
Y
Liou
Robert
R
Best
Fang
F
Zhao
D000328:Adult; D000927:Anticonvulsants / Q000008:administration & dosage / Q000737:chemistry*; D002648:Child; D002851:Chromatography, High Pressure Liquid; D004339:Drug Compounding; D004349:Drug Packaging; D004355:Drug Stability; D004356:Drug Storage; D004827:Epilepsy / Q000188:drug therapy; D006801:Humans; D014677:Pharmaceutical Vehicles / Q000737:chemistry*; D011126:Polypropylenes; D013535:Suspensions; D013997:Time Factors; D014230:Triazoles / Q000008:administration & dosage / Q000737:chemistry*
D000927:Anticonvulsants; D014677:Pharmaceutical Vehicles; D011126:Polypropylenes; D013535:Suspensions; D014230:Triazoles; C079703:rufinamide