Valerian
»Valerian consists of the subterranean parts of Valeriana officinalisLinné(Fam.Valerianaceae)including the rhizome,roots,and stolons.It contains not less than 0.5percent of volatile oil and not less than 0.05percent of valerenic acid (C15H22O2),calculated on the dried basis.
Packaging and storage—
Store in tight containers,protected from light and moisture.
Labeling—
The label states the Latin binomial and,following the official name,the parts of the plant contained in the article.
Botanic characteristics—
Macroscopic—
Rhizome erect,entire or usually cut longitudinally,up to 5cm in length and up to 3cm in diameter,yellowish gray to pale grayish brown,base elongated or compressed,covered by and merging with numerous roots;apex usually bearing a cup-shaped scar from aerial parts,stem bases rarely present;in longitudinal section,pith exhibiting a central cavity traversed by septa.Roots numerous,slender,almost cylindrical,and of the same color as the rhizome,about 10cm in length and up to 3mm in diameter;a few filiform,fragile secondary roots;fracture short.Stolon pale yellowish gray,showing prominent nodes separated by longitudinally striated internodes each 2to 5cm in length;fracture fibrous.
Histology—
Root,with piliferous layer,of papillosed cells,some being developed into root hairs;exodermis,or a single layer of quadrangular to polygonal cells with suberized walls and containing globules of volatile oil;outer cortex of two to four layers of resin-containing cells with thin or collenchymatous,sometimes suberized walls;inner cortex of numerous layers of polygonal to rounded cells filled with starch.Starch granules simple or compound;simple granules rounded,5to 15µm in diameter,sometimes showing a cleft or stellate hilum;compound granules with two to six components,up to 20µm in diameter.Endodermis consisting of a single layer of suberized,tangentially elongated cells,pericycle continuous,starch-filled;parenchyma surrounding the phloem zone;cambium frequently indistinct;vascular bundles forming an interrupted ring surrounding the starch-filled cells.Rhizome in transverse section,different from the root,its structure being complicated by the presence of numerous vascular bundles from root and stolon;epidermis and exodermis partially replaced by poorly developed periderm;central pith wide,including cavities of various sizes,the larger ones being separated by plates of partially sclerified tissue.
Identification—
A:
Transfer about 0.2g of freshly powdered Valerian to a test tube,add 5mLof methylene chloride,shake several times,and allow to stand for 5minutes.Filter,wash the filter with 2mLof methylene chloride,and combine the filtrate and washings in one container.Heat the combined filtrate and washings on a water bath for the minimum time required to evaporate the solvent,and dissolve the residue in 0.2mLof methylene chloride.[NOTE—Retain a portion of this solution for use in Identification test B.]To about 0.1mLof this solution,add 3mLof a mixture of equal volumes of glacial acetic acid and 25%hydrochloric acid,and shake several times:a blue color develops within 15minutes.
B:Thin-Layer Chromatographic Identification Test á201ñ—
Adsorbent:
0.50-mm layer of chromatographic silica gel.
Standard solution:
prepared similarly to the Test solutionexcept to begin with 0.2g of USP Powdered Valerian RS.
Application volume:
duplicate 20-µLportions,applied as 20-mm ×3-mm bands.
Developing solvent system—
Develop the plates twice in a mixture of toluene and ethyl acetate (75:25),each time allowing the solvent front to ascend 10cm above the line of application.Remove the plate from the developing chamber,mark the solvent front,and allow the plate to air-dry.Spray the plate with a mixture of hydrochloric acid and acetic acid (8:2),and heat at 110
for 10minutes.Remove the plate from the oven,cool,and visually examine the plate:the chromatogram of each solution shows a blue to blue-black zone due to valtrate and isovaltrate at an RFvalue of about 0.75;a light brown to dark brown zone due to didrovaltrate at an RFvalue of about 0.65;and a blue to blue-black zone due to acevaltrate at an RFvalue of about 0.55.
for 10minutes.Remove the plate from the oven,cool,and visually examine the plate:the chromatogram of each solution shows a blue to blue-black zone due to valtrate and isovaltrate at an RFvalue of about 0.75;a light brown to dark brown zone due to didrovaltrate at an RFvalue of about 0.65;and a blue to blue-black zone due to acevaltrate at an RFvalue of about 0.55.
C:
The retention time of the valerenic acid peak in the chromatogram of the Test solutioncorresponds to that in the chromatogram of the Standard solution,as obtained in the test for Content of valerenic acid.
Total ash á561ñ:
not more than 12.0%.
Acid-insoluble ash á561ñ:
not more than 5.0%.
Water content á561ñ:
not more than 12.0%.
Extractable matter—
Mix 2g of Valerian,carefully dried at 40and coarsely powdered,with a mixture of 12g of alcohol and 8g of water,and allow to stand for 2hours,shaking frequently.Filter,evaporate 5g of the filtrate on a water bath to dryness,and dry the residue at 105.The weight of the dried residue is not less than 100mg (20%).
and coarsely powdered,with a mixture of 12g of alcohol and 8g of water,and allow to stand for 2hours,shaking frequently.Filter,evaporate 5g of the filtrate on a water bath to dryness,and dry the residue at 105.The weight of the dried residue is not less than 100mg (20%).
Volatile oil á561ñ:
not less than 0.5%,100g of freshly and coarsely comminuted Valerian being used.
Pesticide residues á561ñ:
meets the requirements.
Foreign organic matter á561ñ:
not more than 2.0%.
Microbial enumeration á2021ñ—
The total bacterial count does not exceed 10,000cfu per g,the total combined molds and yeasts count does not exceed 100cfu per g,and it meets the requirements of the tests for absence of Salmonellaspecies and Escherichia coliand for absence of Staphylococcus aureus.
Content of valerenic acid—
Mobile phase—
Prepare a filtered and degassed mixture of methanol and dilute phosphoric acid (1in 200)(80:20).Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ).
Standard solution—
Dissolve an accurately weighed quantity of USP Valerenic Acid RSin 70percent alcohol to obtain a solution having a known concentration of about 0.05mg per mL.
Test solution—
Transfer about 2g of Valerian,reduced to a powder and accurately weighed,to a flask,add 40.0mLof 70percent alcohol,and shake by mechanical means for 2hours at room temperature.Centrifuge,and use the clear extract as the Test solution.
Chromatographic system
(see Chromatography á621ñ)—The liquid chromatograph is equipped with a 225-nm detector and a 4.6-mm ×25-cm column that contains packing L1.The flow rate is about 1.5mLper minute.Chromatograph the Standard solution,and record the peak responses as directed for Procedure:the tailing factor for the valerenic acid peak is not more than 2.0;and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure—
Separately inject equal volumes (about 20µL)of the Standard solutionand the Test solutioninto the chromatograph,record the chromatograms,and measure the responses for the valerenic acid peaks.Calculate the percentage of valerenic acid (C15H22O2)in the portion of Valerian taken by the formula:
2000(C/W)(rU/rS),
in which Cis the concentration,in mg per mL,of USP Valerenic Acid RSin the Standard solution;Wis the weight,in mg,of Valerian taken to prepare the Test solution;and rUand rSare the valerenic acid peak responses obtained from the Test solutionand the Standard solution,respectively:not less than 0.05%is found.
Auxiliary Information—
Staff Liaison:Gabriel I.Giancaspro,Ph.D.,Senior Scientist and Latin American Specialist
Expert Committee:(DSB)Dietary Supplements:Botanicals
USP28–NF23Page 2133
Phone Number:1-301-816-8343