(a den' oh seen).

C10H13N5O4 267.25
6-Amino-9--d-ribofuranosyl-9H-purine;
DEFINITION
Adenosine contains NLT 99.0% and NMT 101.0% of C10H13N5O4, calculated on the dried basis.
IDENTIFICATION
NMT 0.1%
ASSAY
Sample:  200 mg of Adenosine previously dried at 105 for 2 h
Titrimetric system
Mode:  Direct titration
Titrant:  0.1 N perchloric acid VS
Endpoint detection:  Potentiometric
Blank:  50 mL of glacial acetic acid
Analysis:  Dissolve in 50 mL of glacial acetic acid and titrate with 0.1 N perchloric acid VS. Calculate the percentage of Adenosine (C10H13N5O4) in the portion taken:
Result = [(V B) × N × F × 100]/W
 V = = Sample titrant volume (mL) B = = Blank titrant volume (mL) N = = titrant normality (mEq/mL) F = = equivalency factor: 267.25 mg/mEq W = = weight of the Sample (mg)
Acceptance criteria:  99.0%–101.0% on the dried basis
IMPURITIES
NMT 0.1%
NMT 10 ppm
•  Limit of Ammonia
Sample solution:  Suspend 0.5 g in 10 mL of water. Stir for 30 s, and pass through a coarse filter. Dilute the filtrate with water to 15 mL, and use the filtrate.
Standard solution:  0.4 µg/mL of ammonium chloride in water
Analysis:  To the Sample solution and the Standard solution add 0.3 mL of alkaline mercuric–potassium iodide TS, cap the test tubes, and allow to stand for 5 min.
Acceptance criteria:  The Sample solution does not exhibit a more intense yellow color than that of the Standard solution (NMT 4 ppm of ammonia).
•  Limit of Chloride
Sample solution:  Suspend 0.2 g in 10 mL of water. Stir for 30 s, pass through a coarse filter, and use the filtrate.
Standard solution:  2.3 µg/mL of sodium chloride in water
Analysis:  To the Sample solution and 10 mL of the Standard solution add 1 mL of nitric acid and 1 mL of silver nitrate TS, and dilute each solution with water to 40 mL. Allow the solutions to stand for 5 min, protected from light.
Acceptance criteria:  When viewed against a dark background, the Sample solution is not more turbid than the Standard solution (NMT 0.007% chloride).
•  Limit of Sulfate
Sample solution:  Suspend 0.75 g in 15 mL of water. Stir for 30 s, pass through a coarse filter, and use the filtrate.
Standard solution:  Add 0.15 mL of 0.020 N sulfuric acid to 15 mL of water.
Analysis:  To the Sample solution and the Standard solution add 2 mL of barium chloride TS and 1 mL of 3 N hydrochloric acid, dilute each solution with water to 30 mL, and mix. Allow the solutions to stand for 5 min.
Acceptance criteria:  The Sample solution is not more turbid than the Standard solution (NMT 0.02% sulfate).
•  Organic Impurities
Solution A:  6.8 g/L of potassium hydrogen sulfate and 3.4 g/L of tetrabutylammonium hydrogen sulfate in water. Adjust with 2 N potassium hydroxide to a pH of 6.5.
Solution B:  0.1 g/L of sodium azide solution
Mobile phase:  Solution A and Solution B (60:40)
System suitability solution:  0.2 mg/mL each of Adenosine and inosine in Mobile phase
Sample solution:  1.0 mg/mL of Adenosine in Mobile phase
Chromatographic system
Mode:  LC
Detector:  UV 254 nm
Column:  4.6-mm × 25-cm; 5-µm packing L1
Flow rate:  1.5 mL/min
Injection size:  20 µL
System suitability
Sample:  System suitability solution
Suitability requirements
Resolution:  NLT 9.0 between adenosine and inosine
Tailing factor:  NMT 2.5
Relative standard deviation:  NMT 2.0%
[Note—Chromatograph the Sample solution, and adjust the run time to at least twice the retention time of the major peak. ]
Analysis
Sample:  Sample solution
Calculate the percentage of each impurity in the portion of Adenosine taken:
Result = (rU/rT) × 100
 rU = = peak response of each impurity from the Sample solution rT = = sum of all the responses for all peaks from the Sample solution
Acceptance criteria
Individual impurities:  NMT 0.1% each of guanosine, inosine, and uridine, and NMT 0.2% of adenine
Total impurities:  NMT 0.5%
SPECIFIC TESTS
233–238
68 to 72
Test solution:  20 mg/mL in sodium hydroxide solution (1 in 20), determined on a sample previously dried at 105 for 2 h
•  Acidity or Alkalinity: Suspend 1 g in 20 mL of carbon dioxide-free water. Stir for 30 s, and pass through a coarse filter. To each of two 10-mL portions of the filtrate add 0.1 mL of bromocresol purple TS.
Acceptance criteria:  NMT 0.3 mL of 0.01 N sodium hydroxide is required to produce a blue-violet color in one portion. NMT 0.1 mL of 0.01 N hydrochloric acid is required to produce a yellow color in the other portion.
Dry a sample at 105 for 2 h: it loses NMT 0.5% of its weight.