Cyclosporine Oral Solution

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

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

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1 DEFINITION

Cyclosporine Oral Solution is a solution of Cyclosporine in a suitable vehicle. It contains NLT 90.0% and NMT 110.0% of the labeled amount of HN cyclosporine (C₆₂H₁₁₁N₁₁O₁₂)

2 IDENTIFICATION

2.1 A. THIN-LAYER CHROMATOGRAPHY

Solution A: 17 mg/mL of Bismuth subnitrate in 20% acetic acid

Solution B: 400 mg/mL of potassium iodide

Diluent: Methanol and chloroform (4:1)

Standard solution: 1 mg/mL of USP Cyclosporine RS in Diluent

Sample solution: Nominally 1 mg/mL of cyclosporine from Oral Solution in Diluent

2.1.1 Chromatographic system

(See Chromatography (621), Thin-Layer Chromatography.)

Adsorbent: 0.25-mm layer of chromatographic silica gel mixture

Application volume: 10 µL

Developing solvent system 1: Ethyl ether

Developing solvent system 2: Ethyl acetate, methyl ethyl ketone, water, and formic acid (60:40:2:1)

Spray reagent 1: Mix 5 mL of Solution A with 5 mL of Solution B and 20 mL of glacial acetic acid, and dilute with water to 100 mL. Prepare freshly.

Spray reagent 2: Hydrogen peroxide TS

2.1.2 Analysis

Samples: Standard solution and Sample solution

Apply the Standard solution and the Sample solution to the plate. Allow the spots to dry in a current of air, place the plate in a suitable chromatographic chamber, and develop the chromatogram, using Developing solvent system 1, until the solvent front has moved about three-fourths of the length of the plate. Remove the plate from the chamber, mark the solvent front, and allow it to dry. Place the plate in a second chromatographic chamber, and develop the chromatogram in Developing solvent system 2 until the solvent front has moved about three-fourths of the length of the plate. Remove the plate from the chamber, and allow it to dry. Spray the plate with Spray reagent 1. Immediately again spray the plate with Spray reagent 2. Cyclosporine appears as a brown spot having an R, value of about 0.45.

Acceptance criteria: The R_F value of the principal spot of the Sample solution corresponds to that of the Standard solution. Disregard any spots at the origin.

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

3 ASSAY

3.1 PROCEDURE

Mobile phase: Acetonitrile, methanol, water, and phosphoric acid (550:50:400:0.5)

Diluent: Methanol and chloroform (4:1)

Standard solution: 1 mg/mL of USP Cyclosporine RS in Diluent. Use this solution promptly after preparation.

Sample solution: Nominally 1 mg/mL of cyclosporine from Oral Solution in Diluent. Use this solution promptly after preparation.

3.2 Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: LC

Detector: UV 210 nm

Column: 4.6-mm x 25-cm; packing L16

Column temperature: 50°

Flow rate: 1 mL/min

Injection volume: 10 µL

3.3 System suitability

Sample: Standard solution

3.4 Suitability requirements

Capacity factor: 3-10

Column efficiency: NLT 700 theoretical plates

Tailing factor: NMT 1.5

Relative standard deviation: NMT 1.5%

3.5 Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of cyclosporine (C₆₂H₁₁₁N₁₁O₁₂) in the portion of Oral Solution taken: 

                 Result = (r_U/r_S) x (C_S/C_U) × 100

r_U = peak response from the Sample solution

r_S = peak response from the Standard solution S

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

C_U = nominal concentration of the Sample solution (mg/mL)

Acceptance criteria: 90.0%~110.0%

4 OTHER COMPONENTS

4.1 CONTENT OF ALCOHOL (where present)

Internal standard solution: n-Propyl alcohol and butyl alcohol (3:50)

Standard stock solution: 50 mg/mL of dehydrated alcohol in butyl alcohol

Standard solution: 10 mg/mL of alcohol, prepared as follows. Transfer a suitable aliquot of Standard stock solution to a suitable volumetric flask. Add Internal standard solution, using 24% of the final volume, and dilute with butyl alcohol to volume.

Sample solution: Nominally 10 mg/mL of alcohol from Oral Solution, prepared as follows. Transfer a suitable aliquot of Oral Solution to a suitable volumetric flask. Add Internal standard solution, using 24% of the final volume, and dilute with butyl alcohol to volume.

4.2 Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: GC

Detector: Flame ionization

Column: 2-mm x 2-m glass; packed with support S3

4.3 Temperatures

Injection port: 280°

Detector: 290°

Column: See Table 1.

Table 1

Carrier gas: Nitrogen

Flow rate: 35 mL/min

Injection volume: 1 μL. [Note—Make adjustments if necessary to obtain satisfactory chromatography.]

4.4 System suitability

Sample: Standard solution. [Note—The elution order is alcohol, n-propyl alcohol, and butyl alcohol.]

4.5 Suitability requirements

Relative standard deviation: NMT 2.0%

4.6 Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of alcohol (C₆₂H₁₁₁N₁₁O₁₂) in the portion of Oral Solution taken:

                 Result = (R_U/R_S) x (C_S/C_U) × 100

R_U = peak area ratio of alcohol to n-propyl alcohol from the Sample solution

R_S = peak area ratio of alcohol to n-propyl alcohol from the Standard solution S

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

C_U = concentration of the Sample solution (mg/mL)

Acceptance criteria: 80.0%-120.0% of the labeled amount

5 PERFORMANCE TESTS

UNIFORMITY OF DOSAGE UNITS (905): Meets the requirements for oral solution packaged in single-unit containers

DELIVERABLE VOLUME (698): Meets the requirements for oral solution packaged in multiple-unit containers

6 ADDITIONAL REQUIREMENTS

PACKAGING AND STORAGE: Preserve in tight containers.

USP REFERENCE STANDARDS (11)

USP Cyclosporine RS