Guggul
DEFINITION
Guggul is the oleo-gum-resin obtained by incision or produced by spontaneous exudation from the stem and branches of Commiphora wightii (Arnott) Bhandari, also known as Commiphora mukul (Hook. ex. Stocks) Engl. or Balsamodendrum mukul (Hook.) (Fam. Burseraceae). It contains NLT 1.0% of guggulsterones E and Z, calculated on the dried basis as guggulsterone Z.
IDENTIFICATION
•  A. Thin-Layer Chromatographic Identification Test
Standard solution:  10 mg/mL of USP Purified Guggul Extract RS with heating, in acetonitrile
Sample solution:  Transfer about 0.5 g of crushed Guggul to a centrifuge tube. Add 25 mL of acetonitrile, and shake for 1 min. Heat in a water bath for 10–15 min while shaking, cool, centrifuge, and use the supernatant.
Chromatographic system 
Developing solvent system:  A mixture of hexane and ethyl acetate (6:4)
Adsorbent:  0.25-mm layer of chromatographic silica gel mixture, typically 20 cm in length
Application volume:  10 µL
Analysis 
Samples:  Standard solution and Sample solution
Apply the Samples as bands to a suitable plate. Use a saturated chamber. Develop until the solvent front has moved about three-fourths the length of the plate, dry the plate, and examine under UV light at 254 nm.
Acceptance criteria:  The chromatogram of the Sample solution exhibits bands at RF values of about 0.38 and 0.47, due to guggulsterone E and Z, respectively. Both bands correspond in RF values to bands from the Standard solution.
•  B. HPLC Identification Test
Analysis:  Proceed as directed in the test for Content of Guggulsterones E and Z
Acceptance criteria:  The chromatogram of the Sample solution exhibits peaks for guggulsterone E and Z at retention times that correspond to those of Standard solution A.
COMPOSITION
•  Content of Guggulsterones E and Z
Mobile phase:  A mixture of acetonitrile and water (45:55)
Standard solution A:  10 mg/mL of USP Purified Guggul Extract RS with heating, in acetonitrile. Pass the solution through a filter of 0.45-µm pore size before injection.
Standard solution B:  0.1 mg/mL of USP Guggulsterone Z RS in acetonitrile. Pass the solution through a filter of 0.45-µm pore size before injection.
Sample solution:  Transfer about 2.0 g of crushed Guggul to a conical flask, and extract four times each with a 50-mL portion of acetonitrile. Shake for 1 min, and reflux in a water bath for 30 min, stirring with a magnetic stirrer. Evaporate the combined extracts to about 50 mL, and transfer to a 100-mL volumetric flask. Dilute with acetonitrile to volume, and pass through a filter of 0.45-µm pore size before injection.
Chromatographic system 
Mode:  LC
Detector:  UV 242 nm
Column:  4.6-mm × 25-cm; 5-µm packing L1
Flow rate:  2.0 mL/min
Injection size:  20 µL
Column temperature:  27 ± 1
System suitability 
Samples:  Standard solution A and Standard solution B [Note—The relative retention times for guggulsterones E and Z are about 0.69 and 1.0, respectively. ]
Suitability requirements 
Chromatogram similarity:  The chromatogram from Standard solution A is similar to the reference chromatogram provided with the lot of USP Purified Guggul Extract RS being used.
Resolution:  NLT 2.0 between the guggulsterone Z peak and the peak before, Standard solution A
Tailing factor:  NMT 1.5 for the guggulsterone Z peak, Standard solution B
Relative standard deviation:  NMT 2.0% for replicate injections for the guggulsterone Z peak, Standard solution B
Analysis 
Samples:  Standard solution A, Standard solution B, and Sample solution
Allow Standard solution A to elute for NLT two times the retention time of guggulsterone Z, as determined in Standard solution B. Using the chromatogram of Standard solution A and the reference chromatogram provided with the lot of USP Purified Guggul Extract RS being used, identify the retention times of the peaks corresponding to guggulsterone E and guggulsterone Z.
Calculate the percentage of guggulsterones E and Z as guggulsterone Z in the portion of Guggul taken:
Result = (rU/rS) × Cs × (V/W) × 100
rU== sum of the peak responses of guggulsterones E and Z from the Sample solution
rS== peak response of guggulsterone Z from Standard solution B
CS== concentration of USP Guggulsterone Z RS in Standard solution B (mg/mL)
V== final volume of the Sample solution, 100 mL
W== weight of Guggul taken to prepare the Sample solution (mg)
Acceptance criteria:  NLT 1.0% on the dried basis
CONTAMINANTS
•  Heavy Metals, Method III 231: NMT 20 µg/g
SPECIFIC TESTS
•  Botanic Characteristics
Macroscopic:  Guggul occurs in rounded or irregular conglomerates of tears, of variable sizes, light to dark brown, slightly sticky to touch, with characteristic and aromatic odor, and an aromatic, astringent taste.
•  Ethyl Acetate Soluble Extractives
Sample:  About 5.0 g of coarsely powdered Guggul
Analysis:  Transfer the Sample to a glass-stoppered, conical flask. Add 25 mL of solvent hexane, insert a stopper into the flask, shake for 1 h, filter, and discard the filtrate. Repeat twice, and dry the residue in a vacuum over phosphorus pentoxide at room temperature for 8 h. Crush the dried material, and extract with four quantities, each of 25 mL, of ethyl acetate, by shaking each time for 1 h at room temperature, followed by filtration through a sintered glass funnel (porosity No. 3). Evaporate the combined filtrates under reduced pressure in a tared flask, dry the residue in a vacuum over phosphorus pentoxide at room temperature for 12 h, and weigh. Determine the percentage of the ethyl acetate soluble extractives calculated from the weight of Guggul taken.
Acceptance criteria:  22%–30%
•  Loss on Drying 731: Dry 1.0 g at 105 for 2 h: it loses NMT 8.0% of its weight.
•  Residue on Ignition 281: NMT 10.0%, ignited at 800 ± 25
ADDITIONAL REQUIREMENTS
•  Packaging and Storage: Preserve in well-closed containers, protected from light and moisture, and store in a cool place.
•  Labeling: The label states the Latin binomial of the species of Commiphora from which the oleo-gum-resin was obtained and, following the official name, the part of the plant contained in the article.
•  USP Reference Standards 11
USP Guggulsterone Z RS
USP Purified Guggul Extract RS
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Maged H. Sharaf, Ph.D.
Principal Scientific Liaison
1-301-816-8318
(DS2010) Monographs - Dietary Supplements
Reference Standards RS Technical Services
1-301-816-8129
rstech@usp.org
USP35–NF30 Page 1350
Pharmacopeial Forum: Volume No. 34(4) Page 1000