Salicylic Acid
C7H6O3 138.12
Benzoic acid, 2-hydroxy-;
Salicylic acid
[69-72-7].
231
–161USP38
(sal'' i sil' ik as' id).
+'&img=../../images/v38332/cas-69-72-7.gif&casNumber=69-72-7&usp=38&nf=33&chemicalStructureImage=true&ID='+parent.myID,600,500);)
C7H6O3 138.12
Benzoic acid, 2-hydroxy-;
Salicylic acid
[69-72-7].DEFINITION
Change to read:
Salicylic Acid contains NLT
USP38
USP38
IDENTIFICATION
Delete the following:
• USP38
Add the following:
• USP38
ASSAY
Change to read:
• Procedure
Standard solution:
Sample solution:
Chromatographic system
Mode:
Detector:
Column:
Flow rate:
Injection volume:
System suitability
Sample:
Suitability requirements
Tailing factor:
Relative standard deviation:
Analysis
Samples:
Calculate the percentage of salicylic acid (C7H6O3) in the portion of Salicylic Acid taken:
Result = (rU/rS) × (CS/CU) × 100
|
| = | =
|
|
| = | =
|
|
| = | =
|
|
| = | =
|
Acceptance criteria:
USP38
IMPURITIES
• Residue on Ignition 281:
NMT 0.05%
281:
NMT 0.05%
• Chloride and Sulfate, Chloride 221
221
Sample:
1.5 g
Analysis:
Heat the Sample with 75 mL of water until it is dissolved. Cool, add water to restore the original volume, and filter.
Acceptance criteria:
A 25-mL portion of the filtrate shows no more chloride than corresponds to 0.10 mL of 0.020 N hydrochloric acid. (0.014%)
• Chloride and Sulfate, Sulfate 221
221
Sample solution:
1.0 g in alcohol and water (1:1)
Acceptance criteria:
No more sulfate than corresponds to 0.2 mL of 0.020 N sulfuric acid (0.02%)
Delete the following:
231
Sample solution:
Control solution:
Analysis:
Acceptance criteria:
(Official 1-Dec-2015)
Change to read:
• Organic Impurities
Mobile phase:
Prepare as directed in the Assay.
Diluent:
Methanol, glacial acetic acid, and water (70:4:30)
Standard solution:
0.5 mg/mL of USP Salicylic Acid RS, 0.05 mg/mL of USP Salicylic Acid Related Compound A RS, 0.025 mg/mL of USP Salicylic Acid Related Compound B RS, and 0.01 mg/mL of USP Phenol RS in Diluent
USP38
Sample solution:
50 mg/mL of Salicylic Acid in Diluent. Sonicate until completely dissolved.
Chromatographic system
Mode:
LC
Detector:
UV 270 nm
Column:
4.6-mm × 10-cm; 5-µm packing L1
Flow rate:
0.5 mL/min
Injection volume:
2 µL
Samples:
Suitability requirements
[Note—Identify the elution order of phenol by comparing with the Peak identification solution.
Resolution:
USP38
Analysis
Samples:
Standard solution and Sample solution
Calculate the percentage of salicylic acid related compound A, salicylic acid related compound B, and phenol in the portion of Salicylic Acid taken:
Result = (rU/rS) × (CS/CU) × 100
| rU | = | = peak response of salicylic acid related compound A, salicylic acid related compound B, or phenol from the Sample solution |
| rS | = | = peak response of salicylic acid related compound A, salicylic acid related compound B, or phenol from the Standard solution |
| CS | = | = concentration of USP Salicylic Acid Related Compound A RS, USP Salicylic Acid Related Compound B RS, or USP Phenol RS in the Standard solution (mg/mL) |
| CU | = | = concentration of Salicylic Acid in the Sample solution (mg/mL) |
Calculate the percentage of any other individual impurity in the portion of Salicylic Acid taken:
Result = (rU/rS) × (CS/CU) × 100
| rU | = | = peak response of any other individual impurity from the Sample solution |
| rS | = | = peak response of salicylic acid related compound B from the Standard solution |
| CS | = | = concentration of USP Salicylic Acid Related Compound B RS in the Standard solution (mg/mL) |
| CU | = | = concentration of Salicylic Acid in the Sample solution (mg/mL) |
Acceptance criteria:
See Table 1.
USP38
Table 1
| Name
|
Relative Retention Time |
Acceptance Criteria, NMT (%) |
|---|---|---|
| Salicylic acid related compound A | 0.35 | 0.1 |
| Salicylic acid related compound B | 0.45 | 0.05 |
| Phenol | 0.50 | 0.02 |
| Salicylic acid | 1.0 | — |
| Any other individual impurity | — | 0.05 |
| Total impurities | — | 0.2 |
SPECIFIC TESTS
Delete the following:
741:
158–161USP38
ADDITIONAL REQUIREMENTS
• Packaging and Storage:
Preserve in well-closed containers.
Change to read:
• USP Reference Standards 11
USP Phenol RS 
') + '&img=../../images/v38332/cas-108-95-2.gif',600,500);)
USP Salicylic Acid RS
') + '&img=../../images/v38332/cas-69-72-7.gif',600,500);)
USP Salicylic Acid Related Compound A RS
4-Hydroxybenzoic acid.
C7H6O3 138.12
') + '&img=../../images/v38332/c11rs2173.gif',600,500);)
4-Hydroxybenzoic acid.
C7H6O3 138.12
USP38
USP Salicylic Acid Related Compound B RS
4-Hydroxyisophthalic acid.
C8H6O5 182.13
') + '&img=../../images/v38332/c11rs2174.gif',600,500);)
4-Hydroxyisophthalic acid.
C8H6O5 182.13
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
|---|---|---|
| Monograph | Alan R Potts, PhD
Principal Scientific Liaison (301) 816-8364 |
(SM32010) Monographs - Small Molecules 3 |
| Reference Standards | RS Technical Services 1-301-816-8129 rstech@usp.org |
USP38–NF33 Page 5241
Pharmacopeial Forum: Volume No. 39(6)