Minocycline Hydrochloride Extended-Release Tablets

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

DOWNLOAD PDF HERE

1 DEFINITION

Minocycline Hydrochloride Extended-Release Tablets contain NLT 90.0% and NMT 110.0% of the labeled amount of minocycline (C₂₃H₂₇N₃O₇).

2 IDENTIFICATION

A. The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.

B. The UV absorption spectrum of the major peak of the Sample solution and that of the Standard solution exhibit maxima and minima at the same wavelengths, as obtained in the Assay.

3 ASSAY

3.1 Procedure

Protect solutions containing minocycline from light.

Buffer: 3.5 g/L of tetrabutylammonium hydrogen sulfate, 2 g/L of anhydrous citric acid, and 6.8 g/L of monobasic potassium phosphate Adjust with 10 N sodium hydroxide to a pH of 7.0.

Mobile phase: Acetonitrile and Buffer (24:76)

Diluent: Acetonitrile and water (20:80)

Standard solution: 0.045 mg/mL of minocycline from USP Minocycline Hydrochloride RS in Diluent. Store at 4° and use within 24 h.

Sample stock solution: Nominally about 0.9 mg/mL of minocycline from Tablets prepared as follows. Transfer a suitable portion of finely powdered Tablets (NLT 10) to a suitable volumetric flask. Add acetonitrile, using 20% of the final volume, and mix vigorously for 15 min. Add water, using 65% of the final volume, and mix vigorously for 30 min. Dilute with water to volume and mix.

Sample solution: Nominally 0.045 mg/mL of minocycline from Sample stock solution in Diluent. Centrifuge and use the clear supernatant. Store at 4° and use within 24 h.

Chromatographic system

• (See Chromatography 〈621〉, System Suitability.)
• Mode: LC
• Detector: UV 277 nm. When this procedure is used for Identification test B, use a diode array detector set at 200–400 nm.
• Column: 4.6-mm × 15-cm; 5-µm packing L1
• Temperatures
• Column: 35°
• Autosampler: 4°
• Flow rate: 1.3 mL/min
• Injection volume: 10 µL

System suitability

• Sample: Standard solution
• Suitability requirements
• Tailing factor: NMT 1.5
• Relative standard deviation: NMT 1.0%

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of minocycline (C₂₃H₂₇N₃O₇) in the portion of Tablets taken:

Result = (rᵤ/rₛ) × (Cₛ/Cᵤ) × P × F × 100

rᵤ = peak response from the Sample solution

rₛ = peak response from the Standard solution

Cₛ = concentration of USP Minocycline Hydrochloride RS in the Standard solution (mg/mL)

Cᵤ = nominal concentration of minocycline in the Sample solution (mg/mL)

P = potency of minocycline in USP Minocycline Hydrochloride RS (µg/mg)

F = conversion factor, 0.001 mg/µg

Acceptance criteria: 90.0%–110.0%

4 PERFORMANCE TESTS

Change to read:

4.1 Dissolution 〈711〉

Test 1: Protect solutions containing minocycline from light.

Medium: pH 6.8 phosphate buffer (see Reagents and Reference Tables, Solutions, Buffer Solutions); 900 mL

Apparatus 2: 50 rpm

Times: 1, 2, and 5 h

Standard stock solution: 0.5 mg/mL of minocycline from USP Minocycline Hydrochloride RS in Medium

Standard solution: (L/900) mg/mL of minocycline from Standard stock solution in Medium, where L is the label claim of minocycline in mg/Tablet

Sample solution: Pass a portion of the solution under test through a suitable filter.

Instrumental conditions

• Mode: UV
• Analytical wavelength: 348 nm
• Cell: See Table 1.

Table 1

• Blank: Medium

Analysis

Samples: Standard solution, Sample solution, and Blank

Autozero the instrument using the Blank.

Calculate the concentration (Cᵢ) of minocycline (C₂₃H₂₇N₃O₇) in the sample withdrawn from the vessel at each time point (i):

Result = (A_u/Aₛ) × Cₛ × P × F

A_u = absorbance of the Sample solution at time point i

Aₛ = absorbance of the Standard solution

Cₛ = concentration of the Standard solution (mg/mL)

P = potency of minocycline in USP Minocycline Hydrochloride RS (µg/mg)

F = conversion factor, 0.001 mg/µg

Calculate the percentage of the labeled amount (Q) of minocycline (C₂₃H₂₇N₃O₇) dissolved at each time point (i):

Result ₁ = C₁ × V × (1/L) × 100

Result ₂ = {[C₂ × (V − Vₛ)] + (C₁ × Vₛ)} × (1/L) × 100

Result ₃ = ({C₃ × [V − (2 × Vₛ)]} + [(C₂ + C₁) × Vₛ]) × (1/L) × 100

Cᵢ = concentration of minocycline in the portion of sample withdrawn at the specified time point (mg/mL)

V = volume of Medium, 900 mL

L = label claim (mg/Tablet)

Vₛ = volume of the Sample solution withdrawn at each time point (mL)

Tolerances: See Table 2.

Table 2

The percentages of the labeled amounts of minocycline (C₂₃H₂₇N₃O₇) dissolved at the times specified conform to Dissolution 〈711〉, Acceptance Table 2.

Test 2: If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 2.

Protect solutions containing minocycline from light.

Medium: 0.1 N hydrochloric acid; 900 mL

Apparatus 1: 100 rpm

Times: 1, 2, and 4 h

Standard solution: 0.0225 mg/mL of minocycline from USP Minocycline Hydrochloride RS in Medium

Sample solution: At the times specified, withdraw 10 mL of the solution under test and replace with 10 mL of Medium. Pass through a suitable filter. Dilute with Medium to a concentration that is similar to that of the Standard solution.

Instrumental conditions

• Mode: UV
• Analytical wavelength: 348 nm
• Cell: 1 cm
• Blank: Medium

Analysis

Samples: Standard solution and Sample solution

Autozero the instrument using the Blank.

Calculate the concentration (Cᵢ) of minocycline (C₂₃H₂₇N₃O₇) in the sample withdrawn from the vessel at each time point (i):

Result = (A_u/ Aₛ) × Cₛ × D × P × F

A_u = absorbance of the Sample solution at time point i

Aₛ = absorbance of the Standard solution

Cₛ = concentration of the Standard solution (mg/mL)

D = dilution factor (mL/mL)

P = potency of minocycline in USP Minocycline Hydrochloride RS (µg/mg)

F = conversion factor, 0.001 mg/µg

Calculate the percentage of the labeled amount (Q) of minocycline (C₂₃H₂₇N₃O₇) dissolved at each time point (i):

Result ₁ = C₁ × V × (1/L) × 100

Result ₂ = [(C₂ × V) + (C₁ × Vₛ)] × (1/L) × 100

Result ₃ = ({C₃ × V) + [(C₂ + C₁) × Vₛ]} × (1/L) × 100

Cᵢ = concentration of minocycline in the portion of sample withdrawn at the specified time point (mg/mL)

V = volume of Medium, 900 mL

L = label claim (mg/Tablet)

Vₛ = volume of the Sample solution withdrawn at each time point and replaced with Medium (mL)

Tolerances: See Table 3.

Table 3

The percentages of the labeled amounts of minocycline (C₂₃H₂₇N₃O₇) dissolved at the times specified conform to Dissolution 〈711〉, Acceptance Table 2.

Test 3: If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 3.

Protect solutions containing minocycline from light.

Medium: 0.1 N hydrochloric acid; 900 mL

Apparatus 1: 100 rpm

Times: 0.5, 1.5, and 4 h

Standard solution: 0.021 mg/mL of minocycline from USP Minocycline Hydrochloride RS in Medium

Sample solution: At the times specified, withdraw 10 mL of the solution under test and replace with 10 mL of Medium. Pass through a suitable filter. Dilute with Medium to a concentration that is similar to that of the Standard solution.

Instrumental conditions

• Mode: UV
• Analytical wavelength: 265 nm
• Cell: 1 cm
• Blank: Medium

Analysis

Samples: Standard solution and Sample solution

Autozero the instrument using the Blank.

Calculate the concentration (Cᵢ) of minocycline (C₂₃H₂₇N₃O₇) in the sample withdrawn from the vessel at each time point (i):

Result = (A_u/Aₛ) × Cₛ × D × P × F

A_u = absorbance of the Sample solution at time point i

Aₛ = absorbance of the Standard solution

Cₛ = concentration of the Standard solution (mg/mL)

D = dilution factor (mL/mL)

P = potency of minocycline in USP Minocycline Hydrochloride RS (µg/mg)

F = conversion factor, 0.001 mg/µg

Calculate the percentage of the labeled amount (Q) of minocycline (C₂₃H₂₇N₃O₇) dissolved at each time point (i):

Result ₁ = C₁ × V × (1/L) × 100

Result ₂ = [(C₂ × V) + (C₁ × Vₛ)] × (1/L) × 100

Result ₃ = ({C₃ × V) + [(C₂ + C₁) × Vₛ]} × (1/L) × 100

Cᵢ = concentration of minocycline in the portion of sample withdrawn at the specified time point (mg/mL)

V = volume of Medium, 900 mL

L = label claim (mg/Tablet)

Vₛ = volume of the Sample solution withdrawn at each time point and replaced with Medium (mL)

Tolerances: See Table 4.

Table 4

The percentages of the labeled amounts of minocycline (C₂₃H₂₇N₃O₇) dissolved at the times specified conform to Dissolution 〈711〉, Acceptance Table 2.

Test 4: If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 4.

Protect solutions containing minocycline from light.

Medium: 0.1 N hydrochloric acid; 900 mL

Apparatus 1: 100 rpm

Times: 1, 2, and 4 h

Standard solution: (L/900) mg/mL of minocycline from USP Minocycline Hydrochloride RS in Medium, where L is the label claim of minocycline in mg/Tablet

Sample solution: At the times specified, withdraw 5 mL of the solution under test and replace with 5 mL of Medium. Pass through a suitable filter. Dilute with Medium to a concentration that is similar to that of the Standard solution.

Instrumental conditions

• Mode: UV
• Analytical wavelength: 353 nm
• Cell: 1 cm
• Blank: Medium

Analysis

Samples: Standard solution and Sample solution

Autozero the instrument using the Blank.

Calculate the concentration (Cᵢ) of minocycline (C₂₃H₂₇N₃O₇) in the sample withdrawn from the vessel at each time point (i):

Result = (A_u/Aₛ) × Cₛ × D × P × F

A_u = absorbance of the Sample solution at time point i

Aₛ = absorbance of the Standard solution

Cₛ = concentration of the Standard solution (mg/mL)

D = dilution factor (mL/mL)

P = potency of minocycline in USP Minocycline Hydrochloride RS (µg/mg)

F = conversion factor, 0.001 mg/µg

Calculate the percentage of the labeled amount (Q) of minocycline (C₂₃H₂₇N₃O₇) dissolved at each time point (i):

Result ₁ = C₁ × V × (1/L) × 100

Result ₂ = [(C₂ × V) + (C₁ × Vₛ)] × (1/L) × 100

Result ₃ = ({C₃ × V) + [(C₂ + C₁) × Vₛ]} × (1/L) × 100

Cᵢ = concentration of minocycline in the portion of sample withdrawn at the specified time point (mg/mL)

V = volume of Medium, 900 mL

L = label claim (mg/Tablet)

Vₛ = volume of the Sample solution withdrawn at each time point and replaced with Medium (mL)

Tolerances: See Table 5.

Table 5

The percentages of the labeled amounts of minocycline (C₂₃H₂₇N₃O₇) dissolved at the times specified conform to Dissolution 〈711〉, Acceptance Table 2.

Test 5: If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 5.

Protect solutions containing minocycline from light.

Medium: 0.1 N hydrochloric acid; 900 mL

Apparatus 1: 40 mesh, 100 rpm

Times: 0.5, 1.5, and 4 h

Standard stock solution: 0.22 mg/mL of minocycline from USP Minocycline Hydrochloride RS prepared as follows. Transfer a suitable amount of USP Minocycline Hydrochloride RS to a suitable volumetric flask, and dissolve with 10% of the flask volume of Medium. Dilute with water to volume.

Standard solution: 0.022 mg/mL of minocycline in Medium from the Standard stock solution

Sample solution: At the times specified, withdraw 10 mL of the solution under test and replace with 10 mL of Medium. Pass through a suitable filter and discard the first 5 mL. Dilute with Medium to a concentration that is similar to that of the Standard solution.

Instrumental conditions and Analysis: Proceed as directed in Test 4.

Tolerances: See Table 6.

Table 6

The percentages of the labeled amount of minocycline (C₂₃H₂₇N₃O₇) dissolved at the times specified conform to Dissolution 〈711〉, Acceptance Table 2.

Test 6: If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 6.

Protect solutions containing minocycline from light.

Medium: 0.1 N hydrochloric acid; 900 mL

Apparatus 1: 100 rpm

Times: 1, 2, and 4 h

Mobile phase: Dimethylformamide, tetrahydrofuran, 0.2 M ammonium oxalate solution, and 0.01 M edetate disodium solution (120:80:600:180). Adjust with ammonium hydroxide to a pH of 7.2.

Standard stock solution: 0.55 mg/mL of minocycline from USP Minocycline Hydrochloride RS prepared as follows. Transfer a suitable amount of USP Minocycline Hydrochloride RS to a suitable volumetric flask, and dissolve with 70% of the flask volume of Medium and sonicate for 5 min. Dilute with Medium to volume.

Standard solution: (L/900) mg/mL of minocycline from Standard stock solution in Medium, where L is the label claim of minocycline in mg/Tablet

Sample solution: At the times specified, withdraw 10 mL of the solution under test and replace with 10 mL of Medium. Pass through a suitable filter and dilute with Medium to a concentration that is similar to that of the Standard solution.

Chromatographic system

• (See Chromatography 〈621〉, System Suitability.)
• Mode: LC
• Detector: UV 280 nm
• Column: 4.6-mm × 15-cm; 5-µm packing L1
• Temperatures
• Column: 40°
• Autosampler: 10°
• Flow rate: 1.5 mL/min
• Injection volume: 50 µL
• Run time: NLT 1.5 times the retention time of minocycline

System suitability

• Sample: Standard solution
• Suitability requirements
• Relative standard deviation: NMT 2.0%

Analysis

Samples: Standard solution and Sample solution

Calculate the concentration (Cᵢ) of minocycline (C₂₃H₂₇N₃O₇) in the sample withdrawn from the vessel at each time point (i):

Result = (r_u/ rₛ) × Cₛ × P × F

r_u = peak response of minocycline from the Sample solution at time point i

rₛ = peak response of minocycline from the Standard solution

Cₛ = concentration of the Standard solution (mg/mL)

P = potency of minocycline in USP Minocycline Hydrochloride RS (µg/mg)

F = conversion factor, 0.001 mg/µg

Calculate the percentage of the labeled amount (Q) of minocycline (C₂₃H₂₇N₃O₇) dissolved at each time point (i):

Result ₁ = C₁ × V × (1/L) × 100

Result ₂ = [(C₂ × V) + (C₁ × Vₛ)] × (1/L) × 100

Result ₃ = ({C₃ × V) + [(C₂ + C₁) × Vₛ]} × (1/L) × 100

Cᵢ = concentration of minocycline in the portion of sample withdrawn at the specified time point (mg/mL)

V = volume of Medium, 900 mL

L = label claim (mg/Tablet)

Vₛ = volume of the Sample solution withdrawn at each time point and replaced with Medium (mL)

Tolerances: See Table 7.

Table 7

The percentages of the labeled amount of minocycline (C₂₃H₂₇N₃O₇) dissolved at the times specified conform to Dissolution 〈711〉, Acceptance Table 2.

Test 7: If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 7.

Protect solutions containing minocycline from light.

Medium: 0.1 N hydrochloric acid; 900 mL

Apparatus 1: 100 rpm

Times: 1, 2, and 4 h

Standard solution: 0.015 mg/mL of minocycline from USP Minocycline Hydrochloride RS in Medium. Sonicate to dissolve if necessary.

Sample solution: At the times specified, withdraw 15 mL of the solution under test and replace with 15 mL of Medium. Pass through a suitable filter of 0.45-µm pore size. Dilute with Medium to a concentration that is similar to that of the Standard solution.

Instrumental conditions

• Mode: UV
• Analytical wavelength: 348 nm
• Blank: Medium

Analysis

Samples: Standard solution and Sample solution

Calculate the concentration (Cᵢ) of minocycline (C₂₃H₂₇N₃O₇) in the sample withdrawn from the vessel at each time point (i):

Result = (A_u/Aₛ) × Cₛ × D × P × F

A_u = absorbance of minocycline from the Sample solution at time point i

Aₛ = absorbance of minocycline from the Standard solution

Cₛ = concentration of USP Minocycline Hydrochloride RS from the Standard solution (mg/mL)

D = dilution factor for the Sample solution

P = potency of minocycline in USP Minocycline Hydrochloride RS (µg/mg)

F = conversion factor, 0.001 mg/µg

Calculate the percentage of the labeled amount of minocycline (C₂₃H₂₇N₃O₇) dissolved at each time point (i):

Result ₁ = C₁ × V × (1/L) × 100

Result ₂ = [(C₂ × V) + (C₁ × Vₛ)] × (1/L) × 100

Result ₃ = ({C₃ × V) + [(C₂ + C₁) × Vₛ]} × (1/L) × 100

Cᵢ = concentration of minocycline in the portion of sample withdrawn at time point i (mg/mL)

V = volume of Medium, 900 mL

L = label claim (mg/Tablet)

Vₛ = volume of the Sample solution withdrawn at each time point and replaced with Medium (mL)

Tolerances: See Table 8.

Table 8

The percentages of the labeled amounts of minocycline (C₂₃H₂₇N₃O₇) dissolved at the times specified conform to Dissolution 〈711〉, Acceptance Table 2.

Test 8: If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 8.

Protect solutions containing minocycline from light.

Medium: 0.1 N hydrochloric acid; 900 mL

Apparatus 1: 100 rpm

Times: 0.5, 1.5, and 4 h

Mobile phase: Dimethylformamide, tetrahydrofuran, 0.2 M ammonium oxalate solution, and 0.01 M edetate disodium solution (120:80:600:180). Adjust with ammonia TS to a pH of 7.0.

Standard solution: (L/900) mg/mL of minocycline from USP Minocycline Hydrochloride RS in Medium, where L is the label claim of minocycline in mg/Tablet. Store the Standard solution in a refrigerator.

Sample solution: At the times specified, withdraw 10 mL of the solution under test and replace with 10 mL of Medium. Pass through a suitable filter. Store the Sample solution in a refrigerator.

Chromatographic system

• (See Chromatography 〈621〉, System Suitability.)
• Mode: LC
• Detector: UV 348 nm
• Column: 4.6-mm × 15-cm; 5-µm packing L1
• Temperatures
• Autosampler: 5°
• Column: 40°
• Flow rate: 1.5 mL/min
• Injection volume: 10 µL
• Run time: NLT 1.6 times the retention time of minocycline

System suitability

Sample: Standard solution

Suitability requirements

Tailing factor: NMT 2.0

Relative standard deviation: NMT 2.0%

Analysis

Samples: Standard solution and Sample solution

Calculate the concentration (Cᵢ) of minocycline (C₂₃H₂₇N₃O₇) in the sample withdrawn from the vessel at each time point (i):

Result = (r_u/rₛ) × Cₛ × P × F

r_u = peak response of minocycline from the Sample solution at time point i

rₛ = peak response of minocycline from the Standard solution

Cₛ = concentration of the Standard solution (mg/mL)

P = potency of minocycline in USP Minocycline Hydrochloride RS (µg/mg)

F = conversion factor, 0.001 mg/µg

Calculate the percentage of the labeled amount of minocycline (C₂₃H₂₇N₃O₇) dissolved at each time point (i):

Result ₁ = C₁ × V × (1/L) × 100

Result ₂ = [(C₂ × V) + (C₁ × Vₛ)] × (1/L) × 100

Result ₃ = ({C₃ × V) + [(C₂ + C₁) × Vₛ]} × (1/L) × 100

Cᵢ = concentration of minocycline in the portion of sample withdrawn at the specified time point (mg/mL)

V = volume of Medium, 900 mL

L = label claim (mg/Tablet)

Vₛ = volume of the Sample solution withdrawn at each time point (mL)

Tolerances: See Table 9.

Table 9

The percentages of the labeled amounts of minocycline (C₂₃H₂₇N₃O₇) dissolved at the times specified conform to Dissolution 〈711〉, Acceptance Table 2.

Uniformity of Dosage Units 〈905〉: Meet the requirements

5 IMPURITIES

5.1 Organic Impurities

Protect solutions containing minocycline from light.

Buffer, Mobile phase, and Diluent: Prepare as directed in the Assay.

Standard stock solution: Use the Standard solution as directed in the Assay.

Standard solution: 0.009 mg/mL of minocycline from Standard stock solution in Diluent. Store at 4° and use within 24 h.

Sample solution: Use the Sample stock solution as directed in the Assay.

Sensitivity solution: 0.9 µg/mL of minocycline from Standard solution in Diluent. Store at 4° and use within 24 h.

System suitability solution: Heat a portion of the Standard stock solution at 60° for about 2 h and cool. This solution contains a mixture of 4-epiminocycline and minocycline. Store at 4° and use within 24 h.

Chromatographic system: Proceed as directed in the Assay, except use a flow rate of 1 mL/min.

System suitability

• Samples: Standard solution, Sensitivity solution, and System suitability solution
• Suitability requirements
• Resolution: NLT 4.6 between minocycline and 4-epiminocycline, System suitability solution
• Tailing factor: NMT 1.5, Standard solution
• Relative standard deviation: NMT 2.0%, Standard solution
• Signal-to-noise ratio: NLT 10, Sensitivity solution

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of each impurity in the portion of Tablets taken:

Result = (rᵤ/rₛ) × (Cₛ/Cᵤ) × P × F × 100

rᵤ = peak response of each impurity from the Sample solution

rₛ = peak response of minocycline from the Standard solution

Cₛ = concentration of USP Minocycline Hydrochloride RS in the Standard solution (mg/mL)

Cᵤ = nominal concentration of minocycline in the Sample solution (mg/mL)

P = potency of minocycline in USP Minocycline Hydrochloride RS (µg/mg)

F = conversion factor, 0.001 mg/µg

Acceptance criteria: See Table 10. The reporting threshold is 0.1%.

Table 10

ᵃ (4R,4aS,5aR,12aS)-4,7-Bis(dimethylamino)-3,10,12,12a-tetrahydroxy-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydrotetracene-2-carboxamide.

ᵇ Process impurities are controlled in the drug substance and are not to be reported here. They are not included in total degradation products.

ᶜ (4S,4aS,5aR,12aS)-4-Dimethylamino-3,10,12,12a-tetrahydroxy-7-methylamino-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydrotetracene-2-carboxamide.

ᵈ 6-Demethyl-6-deoxytetracycline; (4S,4aS,5aR,12aS)-4-Dimethylamino-3,10,12,12a-tetrahydroxy-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydrotetracene-2-carboxamide.

ᵉ (4S,4aS,12aS)-4,7-Bis(dimethylamino)-3,10,11,12a-tetrahydroxy-1,12-dioxo-1,4,4a,5,12,12a-hexahydrotetracene-2-carboxamide.

ᶠ (4S,4aS,5aR,12aS)-4,7-Bis(dimethylamino)-3,10,12,12a-tetrahydroxy-N-(hydroxymethyl)-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydrotetracene-2-carboxamide.

ᵍ Total degradation products does not include 4-epiminocycline.

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Store in tightly closed containers at controlled room temperature.

Labeling: When more than one Dissolution test is given, the labeling states the Dissolution test used only if Test 1 is not used.

USP Reference Standards 〈11〉

USP Minocycline Hydrochloride RS