This is a general overview of the assay testing procedure for Topiramate tablets. The specific details and requirements may vary depending on the official pharmacopeial methods or the requirements of the testing laboratory. It is important to consult the relevant official compendium or laboratory procedures for precise instructions and guidelines.
The assay testing procedure for Topiramate tablets involves determining the quantity or concentration of the active ingredient, topiramate, in the tablet formulation. Here is a general outline of the procedure:

PURPOSE:

To describe the procedure for Assay Testing Procedure for Topiramate Tablet analysis at the in-process and finished stage of Topiramate Tablet.

SCOPE:

This SAP gives a detailed outline for the finished product analysis of Topiramate Tablet and will cover In process testing activities on a physical, chemical & instrumental basis.

RESPONSIBILITY:

QC Analyst is responsible for physical/chemical testing and preparing standard analytical procedures.
It is the responsibility of QC Manager to assist and ensure the Testing Procedure as per SAP and to make certain that this SAP is followed in its entirety, reviewed regularly, and revised as necessary.

REFERENCE:

USP 43 NF 38 SPECIFICATIONS

MATERIAL AND EQIUPMENT:

• UV Spectrophotometer
• HPLC
• Dissolution apparatus
• Friability apparatus
• Hardness apparatus
• Disintegration Tester
• Vernier Caliper
• Analytical Balance
• Moisture analyzer
• Mortar and pestle
• Spatula
• Filter Paper
• Magnetic Stirrer & Hot Plate
• Sonicator
• Vacuum Pump
• Glassware
• 0.1N HCl
• Ammonium acetate
• Methanol
• Distilled water

PROCEDURE:

FINAL MIX

Assay Testing Procedure for Topiramate Tablet

Description:

A white to off white granular powder.

Procedure: Take 2.0 g of the test sample in a watch glass and observe visually with black background. Check the appearance of color, nature and any visible foreign particles.

Loss on Drying: (By Moisture Analyzer)

Procedure:
Turn on instrument 20 minute before the test. Take 2 g powder spread uniformly on Moisture Analyzer plate. Close the lid and press start button.
NMT 3.0% when determined by LOD Apparatus, Use 2.0 g of powder.

Identification: (By UV SPECTROPHOTOMETER)

A- The spectrum of the sample preparation corresponds to spectrum of the standard preparation as obtained in the assay.
B- The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.
Assay: (Limit: 90%-110%)Compression Weight of Powder/Tablet: 150 mg/tablet

Procedure:
Buffer: 1.54 g/L of ammonium acetate in water. Adjust with glacial acetic acid to a pH of 4.0.
Diluent: Methanol and water (1:4)
Mobile phase: Methanol and Buffer (1:4)
Standard solution: 6 mg/mL of USP Topiramate RS in Diluent
Sample solution: 6 mg/mL of topiramate in Diluent from NLT 12 Tablets, based on the label claim. [NOTE-Shake vigorously for at least 30 min, and pass a portion through a chemical-resistant filter (PTFE) of 0.45um pore size.]

Chromatographic system
(See Chromatography (621), System Suitability.)
Mode: LC
Detector: Refractive index
Column: 4.6-mm x 25-cm; 5-um packing L1
Temperature: 35°
Column: 35°
Detector: 35°
Flow rate: 1.5 mL/min
Injection size: 100 uL

System suitability
Sample: Standard solution

Suitability requirements
Relative standard deviation: NMT 2.0%

Analysis
Samples: Standard solution and Sample solution
Calculate the percentage of topiramate (C12H21NO8S) in the portion of Tablets taken:

Result=(Ru/Rs) x (Cs/Cu) x 100

Ru= peak response from the Sample solution
Rs= peak response from the Standard solution
Cs= concentration of USP Topiramate RS in the Standard solution(mg/mL)
Cu= Nominal concentration of Topiramate in the Sample solution(mg/mL)

Calculations:
Sample AUC x Standard Concentration x Ave. Weight of Tablet x Potency
Standard AUC x Sample Concentration x Label Claim

Limit: Topiramate: 90%-110% of the labeled amount

Dissolution Test:

USP Apparatus: USP Apparatus II Peddle
Medium: 900mL water, deaerated
Speed: 50 rpm
Time: 20 Minute
Medium Temperature: 37º ± 0.5º
Recommended Sampling Time:20 Minute
Diluent: Dissolution medium
Mobile phase: 0.1% trifluoroacetic acid in water and methanol (1:1)
Standard solution: 0.1 mg/mL of USP Topiramate RS in Medium
Sample solution: Pass a portion of the solution under test through a suitable filter of 1um pore size.

Chromatographic system
(See Chromatography (621), System Suitability.)
Mode: LC
Detector: Refractive index
Guard column: 4.0-mm x 1 cm
Column: 4.6-mm x 25-cm; 5 um packing L11

Temperature
Column: 40°
Detector: 40°
Flow rate: 1.2 mL/min
Injection size: 100 uL

System suitability
Sample: Standard solution

Suitability requirements
Relative standard deviation: NMT2.0%

Analysis
Samples: Standard solution and Sample solution
Calculate the percentage of topiramate (C12H21NO8S)dissolved:
Result=(ru/rs) x (Cs/L) x V x 100
ru=peak response from the Sample solution
rs= peak response from the Standard solution
Cs =concentration of USP Topiramate RS in the Standard solution (mg/mL)
L = label claim (mg/Tablet)
V =volume of Medium, 900 mL

Tolerances:
The amount of drug dissolve in solution for each tablet is not less Than 80% Q of the amount stated on the label for topiramate at20 minutes.