Desoxycholic Acid
C24H40O4 392.57
Deoxycholic acid;
13
,12-Dihydroxycholanic acid
[83-44-3].
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C24H40O4 392.57
Deoxycholic acid;
13
,12-Dihydroxycholanic acid
[83-44-3].DEFINITION
Desoxycholic Acid contains NLT 98.0% and NMT 102.0% of C24H40O4, calculated on the dried basis.
IDENTIFICATION
• Add 2 drops of benzaldehyde and 3 drops of 75% sulfuric acid to about 10 mg of Desoxycholic Acid, heat at 50
for 5 min, and then add 10 mL of glacial acetic acid. A green color appears. (Cholic acid produces a brown color.)
for 5 min, and then add 10 mL of glacial acetic acid. A green color appears. (Cholic acid produces a brown color.) ASSAY
• Procedure
Sample:
500 mg
Analysis:
Transfer the Sample into a 250-mL Erlenmeyer flask, and add 20 mL of water and 40 mL of alcohol. Cover the flask with a watch glass, heat the mixture gently on a steam bath until the Sample is dissolved, and allow the mixture to cool to room temperature. Add a few drops of phenolphthalein TS to the solution, and titrate with 0.1 N sodium hydroxide to a pink endpoint that persists for 15 s. Each mL of 0.1 N sodium hydroxide is equivalent to 39.26 mg of C24H40O4.
Acceptance criteria:
98.0%–102.0% on the dried basis
IMPURITIES
Inorganic Impurities
• Residue on Ignition 
281
:
NMT 0.2%, using 1.0 g
281:
NMT 0.2%, using 1.0 g
• Limit of Lead
[Note—Select reagents having as low a lead content as practicable, and store all solutions in high-density polyethylene containers. Rinse all plastic and glassware thoroughly with warm, 50% nitric acid followed by water. ]
Standard lead solution:
Prepare as directed under Heavy Metals 231, Special Reagents.
231, Special Reagents.
Standard solutions:
[Note—Prepare these solutions on the day of use. ] Transfer 10.0 and 50.0 mL of the Standard lead solution into two separate 100-mL volumetric flasks, add 10 mL of 3 N hydrochloric acid to each, and dilute with water to volume. The third standard, 10.0 µg/mL, is taken directly from the Standard lead solution.
Sample solution:
Transfer 10.0 g of Desoxycholic Acid, weighed to the nearest 0.1 mg, into an evaporating dish. Add 5 mL of 25% sulfuric acid (made by adding 25 mL of sulfuric acid to 75 mL of water), and distribute the 25% sulfuric acid solution uniformly. Within a hood, place the dish on a steam bath to evaporate most of the water. Place the dish on a burner, and slowly pre-ash the remaining Sample solution by expelling most of the sulfuric acid. Place the dish in a muffle furnace that has been set at 525, and ash the contents of the dish until the residue appears free from carbon. Cool, and cautiously wash down the inside of the evaporation dish with water. Add 5 mL of 1 N hydrochloric acid. Place the dish on a steam bath, and evaporate to dryness. Add 1.0 mL of 3 N hydrochloric acid and approximately 5 mL of water, and heat briefly on a steam bath to dissolve any residue. Transfer to a 10-mL volumetric flask, dilute with water to volume, and mix.
, and ash the contents of the dish until the residue appears free from carbon. Cool, and cautiously wash down the inside of the evaporation dish with water. Add 5 mL of 1 N hydrochloric acid. Place the dish on a steam bath, and evaporate to dryness. Add 1.0 mL of 3 N hydrochloric acid and approximately 5 mL of water, and heat briefly on a steam bath to dissolve any residue. Transfer to a 10-mL volumetric flask, dilute with water to volume, and mix.
Sample blank:
Prepare by ashing 5 mL of 25% sulfuric acid solution. Cool, and cautiously wash down the inside of the evaporation dish with water. Add 5 mL of 1 N hydrochloric acid. Place the dish on a steam bath, and evaporate to dryness. Add 1.0 mL of 3 N hydrochloric acid and approximately 5 mL of water, and heat briefly on a steam bath to dissolve any residue. Transfer to a 10-mL volumetric flask, dilute with water to volume, and mix.
Spectrometric conditions
Mode:
Atomic absorption
Analytical wavelength:
283.3 nm
Lamp:
Lead electrodeless discharge
Flame:
Air–acetylene flame
Slit width:
0.7 nm
Instrument blank:
Water
Standard curve
Samples:
Standard solutions and Sample blank
Plot:
Corrected absorbance values versus their corresponding concentration (µg/mL). [Note—Determine corrected absorbance values by subtracting the absorbance of the Sample blank from the absorbance of the Standard solutions. ]
Analysis
Samples:
Sample solution and Sample blank
[Note—Determine corrected absorbance values by subtracting the absorbance of the Sample blank from the absorbance of the Sample solution. ]
From the Standard curve, determine the lead concentration in the Sample solution. Calculate the lead content, in ppm, in the portion of Desoxycholic Acid taken:
Result = CS/W × V
| CS | = | = concentration of lead from the Standard curve (µg/mL) |
| W | = | = weight of the sample taken (g) |
| V | = | = final volume of the sample (mL) |
Acceptance criteria:
NMT 4 ppm
SPECIFIC TESTS
• Melting Range or Temperature, Class I 741:
172–175
741:
172–175
• Loss on Drying 731:
Dry a sample at 140 under vacuum of NMT 5 mm of mercury for 4 h: it loses NMT 1% of its weight.
731:
Dry a sample at 140 under vacuum of NMT 5 mm of mercury for 4 h: it loses NMT 1% of its weight.
ADDITIONAL REQUIREMENTS
• Packaging and Storage:
Preserve in tight containers. No storage requirements specified.
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
|---|---|---|
| Monograph | Robert H. Lafaver, M.S.
Scientific Liaison 1-301-816-8335 |
(EXC2010) Monographs - Excipients |
USP35–NF30 Page 1779
Pharmacopeial Forum: Volume No. 34(6) Page 1523