Printed on: Fri Jan 05 2024, 09:02:16 PM(EST) Status: Currently Official on 06-Jan-2024 DocId: GUID-4E0ABC51-B775-4030-AF50-96DD5CE477DE_6_en-US

Printed by: USP NF Official Date: Official as of 01-Jul-2022 Document Type: USP @2024 USPC
Do Not Distribute DOI Ref: cc9p2 DOI: https://doi.org/10.31003/USPNF_M28230_06_01
1

Result = (rU/rS) × (CS/CU) × P × F × 100

Doxycycline Capsules
rU = peak response from the Sample solution
DEFINITION
Doxycycline Capsules contain NLT 90.0% and NMT 120.0% rS = peak response from the Standard solution
of the labeled amount of doxycycline (C22H24N2O8). CS = concentration of USP Doxycycline Hyclate RS in
the Standard solution (mg/mL)
IDENTIFICATION CU = nominal concentration of doxycycline in the
• A. The UV spectrum of the major peak of the Sample Sample solution (mg/mL)
solution corresponds to that of the Standard solution, as P = potency of doxycycline in USP Doxycycline
obtained in the Assay. Hyclate RS (µg/mg)
• B. The retention time of the major peak of the Sample F = conversion factor, 0.001 mg/µg
solution corresponds to that of the Standard solution, as
obtained in the Assay. Acceptance criteria: 90.0%–120.0%
ASSAY PERFORMANCE TESTS
• PROCEDURE • DISSOLUTION á711ñ
Protect solutions containing doxycycline from light. Test 1
Solution A: Transfer 3.1 g of monobasic potassium Medium: 0.01 N hydrochloric acid; 900 mL
phosphate, 0.5 g of edetate disodium, and 0.5 mL of Apparatus 2: 75 rpm
triethylamine to a 1000-mL volumetric flask. Add about Time: 60 min
850 mL of water and mix. Dilute with water to volume and Standard solution: A known concentration of USP
adjust with 1 N sodium hydroxide to a pH of 8.5 ± 0.1. Doxycycline Hyclate RS in Medium
Solution B: Methanol Sample solution: Filter a portion of the solution under test

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Mobile phase: See Table 1. and dilute with Medium, if necessary.
Instrumental conditions
Table 1 (See Ultraviolet-Visible Spectroscopy á857ñ.)
Time Solution A Solution B Mode: UV
(min) (%) (%)
ci Analytical wavelength: Maximum absorbance at about
268 nm
0.0 90 10
Analysis
2.0 90 10 Samples: Standard solution and Sample solution
Calculate the percentage of the labeled amount of
4.0 60 40
doxycycline (C22H24N2O8) dissolved:
ffi
6.0 90 10

9.0 90 10
Result = (AU/AS) × (CS/L) × V × P × F × 100

AU = absorbance of the Sample solution

Diluent: 0.01 N hydrochloric acid AS = absorbance of the Standard solution
Standard solution: 0.12 mg/mL of USP Doxycycline CS = concentration of USP Doxycycline Hyclate RS in
Hyclate RS in Diluent. Sonicate as needed to dissolve.
O

the Standard solution (mg/mL)

Sample solution: Nominally 0.1 mg/mL of doxycycline in L = label claim (mg/Capsule)
Diluent, prepared as follows. Transfer an adequate amount V = volume of Medium, 900 mL
of doxycycline from the contents of NLT 20 Capsules to a P = potency of doxycycline in USP Doxycycline
suitable volumetric flask. Add 80% of the final volume of Hyclate RS (µg/mg)
Diluent, sonicate for about 5 min, shake for about 15 min, F = conversion factor, 0.001 mg/µg
and dilute with Diluent to volume. Centrifuge a portion of
the solution for 10 min at 3000 rpm and use the Tolerances: NLT 85% (Q) of the labeled amount of
supernatant for analysis. doxycycline (C22H24N2O8) is dissolved.
Chromatographic system Test 2: If the product complies with this test, the labeling
(See Chromatography á621ñ, System Suitability.) indicates that it meets USP Dissolution Test 2.
Mode: LC Medium: 0.01 N hydrochloric acid; 900 mL
Detector: UV 270 nm. For Identification A, a diode array Apparatus 2: 50 rpm, with sinkers
detector may be used in the wavelength range of 200– Time: 30 min
400 nm. Standard solution: A known concentration of USP
Column: 2.1-mm × 5-cm; 1.7-µm packing L7. [NOTE—A Doxycycline Hyclate RS in Medium
1.7-µm guard column with packing L7 was used during Sample solution: Filter a portion of the solution under test
method validation.] and dilute with Medium, if necessary.
Column temperature: 60° Instrumental conditions
Flow rate: 0.6 mL/min (See Ultraviolet-Visible Spectroscopy á857ñ.)
Injection volume: 5 µL Mode: UV
System suitability Analytical wavelength: 268 nm
Sample: Standard solution Analysis
Suitability requirements Samples: Standard solution and Sample solution
Tailing factor: NMT 1.5 Calculate the percentage of the labeled amount of
Relative standard deviation: NMT 2.0% doxycycline (C22H24N2O8) dissolved:
Analysis
Samples: Standard solution and Sample solution Result = (AU/AS) × (CS/L) × V × P × F × 100
Calculate the percentage of the labeled amount of
doxycycline (C22H24N2O8) in the portion of Capsules AU = absorbance of the Sample solution
taken:

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Printed on: Fri Jan 05 2024, 09:02:16 PM(EST) Status: Currently Official on 06-Jan-2024 DocId: GUID-4E0ABC51-B775-4030-AF50-96DD5CE477DE_6_en-US
Printed by: USP NF Official Date: Official as of 01-Jul-2022 Document Type: USP @2024 USPC
Do Not Distribute DOI Ref: cc9p2 DOI: https://doi.org/10.31003/USPNF_M28230_06_01
2

AS = absorbance of the Standard solution rS = peak response of doxycycline from the Standard
CS = concentration of USP Doxycycline Hyclate RS in solution
the Standard solution (mg/mL) CS = concentration of USP Doxycycline Hyclate RS in
L = label claim (mg/Capsule) the Standard solution (mg/mL)
V = volume of Medium, 900 mL CU = nominal concentration of doxycycline in the
P = potency of doxycycline in USP Doxycycline Sample solution (mg/mL)
Hyclate RS (µg/mg) P = potency of doxycycline in USP Doxycycline
F = conversion factor, 0.001 mg/µg Hyclate RS (µg/mg)
F = conversion factor, 0.001 mg/µg
Tolerances: NLT 85% (Q) of the labeled amount of
doxycycline (C22H24N2O8) is dissolved. Acceptance criteria: See Table 2. Disregard peaks less than
• UNIFORMITY OF DOSAGE UNITS á905ñ: Meet the 0.1%.
requirements
Table 2
IMPURITIES Relative Acceptance
• ORGANIC IMPURITIES Retention Criteria,
Protect solutions containing doxycycline from light. Name Time NMT (%)
Mobile phase, Diluent, and Chromatographic system:
Methacyclinea, b 0.64 —
Proceed as directed in the Assay.
System suitability stock solution 1: 1 mg/mL each of USP 4-Epidoxycycline c
0.79 0.5
Doxycycline Related Compound A RS and USP
Doxycycline related
Methacycline Hydrochloride RS in Diluent compound A —
System suitability stock solution 2: 1.2 mg/mL of USP

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(6-epidoxycycline)b, d 0.88
Doxycycline Hyclate RS in Diluent
Doxycycline 1.0 —
System suitability solution: Transfer 5 mL of System
suitability stock solution 2 to a 25-mL volumetric flask, heat Any individual
—
on a steam bath for 60 min, and evaporate to dryness on a unspecified impurity 0.2
hot plate, taking care not to char the residue. Dissolve the Total impurities — 1.0
residue in Diluent, add 0.5 mL of System suitability stock
solution 1, and dilute with Diluent to volume. Pass the
ci
solution through a suitable filter and use the filtrate. This
a (4S,4aR,5S,5aR,12aS)-4-(Dimethylamino)-1,4,4a,5,5a,6,11,12a-octahydro-
3,5,10,12,12a-pentahydroxy-6-methylene-1,11-dioxo-2-
naphthacenecarboxamide.
solution contains a mixture of 4-epidoxycycline, b Process impurities that are controlled in the drug substance are not to be
doxycycline related compound A, methacycline, and reported. They are not to be included in total impurities. They are listed here for
ffi
doxycycline. [NOTE—The solution is stable up to 14 days information only.
when stored in a refrigerator at 2°–8°.] c (4R,4aR,5S,5aR,6R,12aS)-4-(Dimethylamino)-1,4,4a,5,5a,6,11,12a-
Standard solution: 4.6 µg/mL of USP Doxycycline Hyclate octahydro-3,5,10,12,12a-pentahydroxy-6-methyl-1,11-dioxo-2-
RS in Diluent naphthacenecarboxamide.
d (4S,4aR,5S,5aR,6S,12aS)-4-(Dimethylamino)-1,4,4a,5,5a,6,11,12a-
Sample solution: Nominally 2.0 mg/mL of doxycycline in
octahydro-3,5,10,12,12a-pentahydroxy-6-methyl-1,11-dioxo-2-
Diluent, prepared as follows. Accurately weigh and naphthacenecarboxamide.
O

transfer a portion of the composite equivalent to 100.0 mg

of doxycycline to a 50-mL volumetric flask. Add 80% of the ADDITIONAL REQUIREMENTS
final volume of Diluent, sonicate for about 5 min, shake for • PACKAGING AND STORAGE: Preserve in tight, light-resistant
about 15 min, and dilute with Diluent to volume. containers.
Centrifuge a portion of the solution for 10 min at 3000 rpm • LABELING: When more than one Dissolution test is given, the
and use the supernatant for analysis. labeling states the test used only if Test 1 is not used.
System suitability
Samples: System suitability solution and Standard solution Change to read:
Suitability requirements
Resolution: NLT 1.5 between methacycline and • USP REFERENCE STANDARDS á11ñ
4-epidoxycycline; NLT 1.5 between 4-epidoxycycline USP Doxycycline Hyclate RS
and doxycycline related compound A; NLT 2.0 between USP Doxycycline Related Compound A RS
doxycycline related compound A and doxycycline, [NOTE—May be available as a free base or a
System suitability solution hydrochloride salt.]
Relative standard deviation: NMT 5.0% for the (4S,4aR,5S,5aR,6S,12aS)-4-(Dimethylamino)-1,4,4a,
doxycycline peak, Standard solution 5,5a,6,11,12a-octahydro-3,5,10,12,12a-pentahydroxy-
Analysis 6-methyl-1,11-dioxo-2-naphthacenecarboxamide.
Samples: Standard solution and Sample solution C22H24N2O8 ▲444.44▲ (ERR 1-Jul-2022)
Calculate the percentage of each impurity in the portion of (4S,4aR,5S,5aR,6S,12aS)-4-(Dimethylamino)-1,4,4a,
Capsules taken: 5,5a,6,11,12a-octahydro-3,5,10,12,12a-pentahydroxy-
6-methyl-1,11-dioxo-2-naphthacenecarboxamide
Result = (rU/rS) × (CS/CU) × P × F × 100 ▲
hydrochloride▲ (ERR 1-Jul-2022).
C22H24N2O8 · HCl ▲480.90▲ (ERR 1-Jul-2022)
rU = peak response of each impurity from the Sample
solution USP Methacycline Hydrochloride RS

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