Terbinafine Oral Suspension
Terbinafine Oral Suspension contains NLT 90.0% and NMT 110.0% of the labeled content of terbinafine hydrochloride (C21H25N·HCl). Prepare Terbinafine Oral Suspension (28.1 mg/mL as hydrochloride) equivalent to 25 mg of Terbinafine per mL as follows (see Pharmaceutical CompoundingNonsterile Preparations 795).
Calculate the required quantity of each ingredient for the total amount to be prepared. If using tablets, place the required number of tablets in a suitable mortar, and comminute the tablets to a fine powder or add Terbinafine Hydrochloride powder. Add the Vehicle in small portions, and triturate to make a smooth paste. Add increasing volumes of the Vehicle to make a terbinafine suspension that is pourable. Transfer the contents of the mortar, stepwise and quantitatively, to a calibrated bottle. Add enough of the Vehicle to bring to final volume, and mix well.
Mobile phase: Acetonitrile and water (2:3), with 0.15% triethylamine and 0.15% phosphoric acid. Make adjustments if necessary.
Standard stock solution: 1.0 mg/mL USP Terbinafine Hydrochloride RS in methanol
Standard solution: Transfer 0.5 mL of Standard stock solution to a 100-mL volumetric flask, dilute with Mobile phase to volume to obtain a solution containing 5 µg/mL of terbinafine hydrochloride, and pass through a suitable filter of 0.22-µm pore size.
Sample solution: Shake thoroughly by hand each bottle of Oral Suspension. Accurately pipet 1.0 mL to a 25-mL volumetric flask. Dilute with methanol to volume to obtain a nominal concentration of 1 mg/mL of terbinafine hydrochloride. Mix the sample again. Accurately pipet 1.0 mL of the diluted terbinafine hydrochloride solution to a 10-mL volumetric flask, and dilute with Mobile phase to volume to obtain a nominal concentration of 5 µg/mL of terbinafine hydrochloride.
Detector: UV 224 nm
Column: 4.6-mm × 15-cm; 3.5-µm packing L1
Flow rate: 0.4 mL/min
Injection size: 10 µL
Sample: Standard solution
[NoteThe retention time of the terbinafine peak is 5.1 min. ]
Relative standard deviation: NMT 5.8%
Samples: Standard solution and Sample solution
Calculate the percentage of the labeled amount of C21H25N·HCl in the volume of Oral Suspension taken:
Result = (rU/rS) × (CS/CU) × 100
Acceptance criteria: 90.0%110.0%
• pH 791: 5.35.7
• Packaging and Storage: Package in tight, light-resistant containers. Store at controlled room temperature or controlled cold temperature.
• Labeling: Label it to state that it is to be well shaken before use, and to state the Beyond-Use Date.
• Beyond-Use Date: NMT 30 days after the date on which it was compounded when stored at controlled room temperature or at controlled cold temperature.
• USP Reference Standards 11
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USP35NF30 Page 4790Pharmacopeial Forum: Volume No. 35(1) Page 96