Cat's Claw Capsules
Cat's Claw Capsules contain Powdered Cat's Claw Extract. Capsules contain NLT 90.0% and NMT 110.0% of the labeled amount of Powdered Extract, calculated as pentacyclic oxindole alkaloids.
• The Sample solution chromatogram exhibits peaks for speciophylline, uncarine F, mitraphylline, isomitraphylline, pteropodine, and isopteropodine at retention times that correspond to those in Standard solution A, as obtained in the test for Content of Pentacyclic Oxindole Alkaloids and Limit of Tetracyclic Oxindole Alkaloids. The content of tetracyclic oxindole alkaloids, calculated as the sum of rhynchophylline and isorhynchophylline, is NMT 25% of the labeled amount of pentacyclic oxindole alkaloids.
• Content of Pentacyclic Oxindole Alkaloids and Limit of Tetracyclic Oxindole Alkaloids
Solution A: Prepare a 10 mM pH 7.0 phosphate buffer by mixing 1 N sodium hydroxide, 1 M monobasic potassium phosphate, and water (3:5:492), and adjust to a pH of 7.0 ± 0.1 by adding more of either solution.
Solution B: Acetonitrile
Solution C: Methanol and glacial acetic acid (99:1)
Mobile phase: See the gradient table below.
Standard solution A: Dissolve an accurately weighed quantity of USP Powdered Cat's Claw Extract RS in methanol, shake for 1 min, and dilute with methanol to obtain a solution having a known concentration of about 0.5 mg/mL of the labeled amount of total oxindole alkaloids. Pass through a filter of 0.45-µm or finer pore size.
Standard solution B: 0.1 mg/mL of USP Isopteropodine RS in methanol. Pass through a nylon filter of 0.45-µm or finer pore size.
Sample solution: Accurately weigh the contents of not fewer than 20 Capsules and pulverize. Transfer an accurately weighed quantity of the powder, equivalent to 20 mg of the labeled amount of pentacyclic oxindole alkaloids, to a 50-mL centrifuge tube. Sonicate with 10 mL of methanol for 10 min. Centrifuge and transfer this solution to a 50-mL volumetric flask. Repeat the above extraction three more times, combining the extracts in the 50-mL volumetric flask, and dilute with methanol to volume. Transfer 3 mL of the solution to a test tube containing 300 mg of polyamide powder, and shake for 1 min. Pass through a nylon filter of 0.45-µm or finer pore size, and discard the first part of the filtrate.
Detector: UV 245 nm
Column: 4.6-mm × 10-cm; endcapped 3-µm packing L1
Flow rate: 0.75 mL/min
Injection size: 10 µL
Samples: Standard solution A and Standard solution B
Chromatogram similarity: The chromatogram obtained using Standard solution A is similar to the Reference Chromatogram provided with the USP Powdered Cat's Claw Extract RS being used.
Tailing factor: NMT 2.0 for the isopteropodine peak, Standard solution B
Relative standard deviation: NMT 2.0% from the isopteropodine peak in repeated injections, Standard solution B
Samples: Standard solution A, Standard solution B, and Sample solution
Measure the areas of the analyte peaks. Identify the retention times of the peaks corresponding to speciophylline, uncarine F, mitraphylline, isomitraphylline, pteropodine, isopteropodine, rhynchophylline, and isorhynchophylline by comparison of the chromatogram of Standard solution A with the Reference Chromatogram provided with the lot of the USP Powdered Cat's Claw Extract RS being used.
Calculate the content, in mg, of speciophylline, uncarine F, mitraphylline, isomitraphylline, pteropodine, and isopteropodine, as isopteropodine, in the portion of Capsules taken:
Result = (rU/rS) × CS × V
Calculate the content, in mg, of total pentacyclic oxindole alkaloids (CC) in the portion of Capsules taken by adding the individual contents of speciophylline, uncarine F, mitraphylline, isomitraphylline, pteropodine, and isopteropodine.
Calculate the percentage of Powdered Cat's Claw Extract with respect to the label claim:
Result = CC × (AWC/W) × (100/LE) × (100/L)
Calculate the percentage of tetracyclic oxindole alkaloids with respect to the content of pentacyclic oxindole alkaloids in the portion of Capsules taken:
Result = (rT/rP) × 100
Acceptance criteria: 90.0%110.0% of the labeled amount of Powdered Extract calculated as pentacyclic oxindole alkaloids; and NMT 25% of tetracyclic oxindole alkaloids with respect to the labeled amount of pentacyclic oxindole alkaloids is found.
• Disintegration and Dissolution of Dietary Supplements 2040: Meets the requirements for Disintegration
• Weight Variation of Dietary Supplements 2091: Meets the requirements
• Microbial Enumeration Tests 2021: The total aerobic microbial count does not exceed 104 cfu/g, and the total combined molds and yeasts count does not exceed 103 cfu/g.
• Absence of Specified Microorganisms 2022: Meets the requirements of the tests for absence of Salmonella species and Escherichia coli.
• Packaging and Storage: Preserve in tight, light-resistant containers, and store at room temperature.
• Labeling: The label states the Latin binomial and, following the official name, the article from which the Capsules were prepared. If prepared with Extract, the label also indicates the quantity, in mg, of Extract per Capsule and the content, in mg, of pentacyclic oxindole alkaloids per 100 mg of Powdered Extract.
• USP Reference Standards 11
USP Isopteropodine RS
USP Powdered Cat's Claw Extract RS
Auxiliary Information Please check for your question in the FAQs before contacting USP.
USP35NF30 Page 1229Pharmacopeial Forum: Volume No. 36(1) Page 148