## STP FOR AZITHROMYCIN TABLETS

1.Description: Visual

2. Average Weight: Check weight of 20 tablets at randomly and calculate the average weight by formula :

wt of 20 tablets (gm) x 1000 / 20. found avg. wt in mg

3.0)    Uniformity of weight:

Weigh 20 tablets selected at random and calculate the average weight. Not more than two of the individual weights deviate from the average weight by more than the percentage shown in table.

Tablets were weighed individually and the percentage of deviation of its weight from the average weight was determined for each tablet. Formula for calculate the percentage of deviation

= (experimental weight – theoretical weight)    x 100%

Theoretical weight

 Average weight of tablets Percentage deviation More than 80mg but Less than 250mg 7.5% 250mg or More 5%

4.0)      Identification Test:

In the Assay, the retention time of the principal peak in the chromatogram obtained with the test solution corresponds to the peak in the chromatogram obtained with the reference solution.

5.0)      Hardness:

The standard method used for tablet hardness testing is compression testing. The tablet is placed between two jaws that crush the tablet. The machine measures the force applied to the tablet and detects when it fractures. Although compressive force is applied to the tablet, along the diameter of the tablet at right angles to the applied force.

6.0)      Disintegration Time

Unless otherwise stated in the individual monograph, introduce one tablet into each tube and add a disc to each tube. The assembly is suspended in the liquid medium in a suitable vessel, preferably a 1-litre beaker. The volume of liquid is such that the wire mesh at its highest point is at least 15mm below the surface of the liquid, and at its lower point is at least 25mm above the bottom of the beaker. At no time should the top of the basket-rack assembly become submerged. There is a thermostatic arrangement for heating the liquid and maintaining the temperature at 37±2°.

If 1 or 2 tablets fail to disintegrate, repeat the test on 12 additional tablets; not less than 16 of the total of 18 tablets tested disintegrate.

If the tablets adhere to the disc and the preparation under examination fails to comply, repeat the test omitting the disc. The preparation complies with the test if all the tablets in the repeat test disintegrate.

7.0)      Dimension of Tablet:

Length, breadth and thickness are determined by vernier in mm

8.0)      Dissolution:

Medium: 900ml of a buffer solution prepared b adding to 6 litres of 0.1 M dibasic sodium phosphate about 40ml of hydrochloric acid, adjusting the pH to 6.0, adding 600mg of trypsin, and mixing.

Time: 45 minutes

Speed: 100 rpm

Limit: NLT 80% of the stated amount of Azithromcin.

Withdraw a suitable volume of the medium and filter through a filter.

Chromatographic system:

• A stainless steel column 25cmX4.6mm packed with end capped polar embedded octadecylsilyl amorphous organosilica polymer (5µm), (such as waters Xterra),
• Mobile phase: a mixture of 10 volumes of a 3.484 per cent w/v solution of dipotassium hydrogen phosphate with the pH previously adjusted to 6.5 with O.P.A., 35 volumes of acetonitrile and 55 volumes of water,
• Flow rate: 1ml per minute,
• Spectrophotometer set at 215nm,
• Injection volume: 100µl

Test solution: The filtrate from the dissolution medium suitably diluted with the mobile phase, if necessary.

Reference solution: A solution of azithromycin reference standard in the dissolution medium suitable diluted with the mobile phase to obtain a solution having the same concentration as that of the test solution.

9.0)      Leak test:

The apparatus is used to test for the integrity of packed strips, blisters and Alu-Alu Blister pack containing tablets. Ensure apparatus bath is filled with purified water upto mark indicated and add 0.5% crystal violet solution in water. Samples are placed into the desiccators and the lid is placed in position. The pump starts to produce a vacuum 15inHg inside the desiccators and the vacuum is held for 1 minute. The sample remains at the required vacuum level for given time interval buzzer will sound after time is over and will cut off the vacuum pump. As the package is immersed in a colored dye solution the venting of the desiccators will allow any holes to be penetrated by the dye and the contents of the flexible packaging will also be stained with the same coloring material.

Examine all the strips for any leakage by opening the pockets manually. If anyone pocket shows evidence of leakage, reject the sample, stop the Blister / Strip machine and immediately take corrective action.

10.0)    Related substance: Determined by liquid chromatography.

Note: Prepare the solution immediately before use.

Solvent mixture: Prepare a 0.173 per cent w/v solution of ammonium dihydrogen phosphate with the pH adjusted to 10.0 with strong ammonia solution. Transfer 350ml of this solution add 300ml of acetonitrile and 350ml of methanol. Mix well.

Test solution: Weigh and powder 20 tablets. Weigh a quantity of the powder containing about 0.2g azithromycin, dissolve in the solvent mixture by shaking mechanically, dilute to 25.0ml with the solvent mixture and filter.

Reference solution (a): A 0.008 per cent w/v solution of azithromycin reference solution in the solvent mixture.

Reference solution (b): A solution containing 0.01 per cent w/v of azithromycin reference standard and azithromycin impurity A reference standard in the solvent mixture.

Chromatographic system:

• A stainless steel column 25cmX4.6mm packed with end-capped octadecylsilyl amorphous organosilica polymer for mass spectrometry (5µm) (such as waters Xterra),
• Column temperature: 60°
• Mobile phase: A. 0.18 per cent w/v solution of anhydrous disodium hydrogen phosphate with the pH adjusted to 8.9 with dilute O.P.A. or with dilute sodium hydrogen solution.
1. a mixture of 25 volumes of methanol and 75 volumes of acetonitrile,
• Flow rate: 1ml per minute,
• A gradient programme using the conditions given below,
• Spectrophotometer set at 210nm,
• Injection volume: 50µl
 Time (in min.) Mobile phase A ( per cent v/v) Mobile phase B ( per cent v/v) 0 50 50 25 45 55 30 40 60 80 25 75 81 50 50 93 50 50

 Name Relative retention time Correction factor Azithromycin impurity L1 0.29 2.3 Azithromycin impurity M2 0.37 0.6 Azithromycin impurity E3 0.43 – Azithromycin impurity F4 0.51 0.3 Azithromycin impurity D5 0.54 – Azithromycin impurity J6 0.54 – Azithromycin impurity I7 0.61 – Azithromycin impurity C8 0.73 – Azithromycin impurity N9 0.76 0.7 Azithromycin impurity H10 0.79 0.1 Azithromycin impurity A11 0.83 – Azithromycin impurity P 0.92 – Azithromycin impurity O12 1.23 – Azithromycin impurity G13 1.26 0.2 Azithromycin impurity B14 1.31 –

Inject reference solution (b). The chromatogram obtained shows peaks corresponding to azithromycin and azithromycin impurity A. The test is not valid unless the resolution between these two peaks is at least 7.0.

Inject reference solution (a) and the test solution. In the chromatogram obtained with the test solution with the test solution, the area of any secondary peak eluting with an relative retention time of about1.3 due to azithromycin impurity B is not more than twice the area of princiapal peak in the chromatogram obtained with reference solution (a) (2.0 per cent). The sum of the areas of all the other secondary peaks is not more than 3 times the area of the principal peak in the chromatogram obtained with reference solution (a) (3.0 per cent). Ignore any peak with an area less than 0.1 times the area of the principal peak in the chromatogram obtained with reference solution (a) (0.1 per cent); ignore the peaks eluting before azithromycin impurity L and after azithromycin impurity B

11.0)    Assay: Determined by liquid chromatography.

Solvent mixture: 40 volumes of acetonitrile and 60 volumes of water.

Test solution: Weigh and powder 20 tablets. Weigh quantity of the powder containing 0.1 g of azithromycin dissolve in the solvent mixture by shaking mechanically, dilute to 100ml with the solvent mixture and filter.

Reference solution (a): A 0.1 per cent w/v solution of azithromycin reference standard in the solvent mixture.

Reference solution (b): A solution containing 0.01 per cent w/v of azithromycin reference standard amd azithromycin impurity A reference standard in the solvent mixture.

Chromatographic system:

• A stainless steel column 25cmX4.6mm packed with end capped polar embedded octadecylsilyl amorphous organosilica polymer (5µm), (such as waters Xterra),
• Mobile phase: a mixture of 10 volumes of a 3.484 per cent w/v solution of dipotassium hydrogen phosphate with the pH previously adjusted to 6.5 with O.P.A., 35 volumes of acetonitrile and 55 volumes of water,
• Flow rate: 1ml per minute,
• Spectrophotometer set at 215nm,
• Injection volume: 100µl

Inject reference solution (b). The chromatogram obtained shows peaks corresponding to azithromycin and azithromycin impurity A. The test is not valid unless the resolution between these two peaks is at least 7.0.

Inject reference solution (a) and the test solution.

Calculate the content of Azithromycin in the tablets.

Acceptance criteria: 90.0%-110.0%

12.0)    MICROBIOLOGICAL PURITY

Perform the test according to requirements of IP,

Total aerobic Microbial count (TAMC): NMT 103 CFU/g

Total combined yeasts/Moulds count (TYMC): NMT 102 CFU/g

Pathogens: in 1gm drug.

Escherichia Coli – Should be absent

Pseudomonas aeroginosa – Should be absent

Salmonella – Should be absent

Staphylococcus aureus– Should be absent

Abbreviations:

Wt.: Weight

mg: Miligram

ml: Milileter

STD: Standard

inHg: Inch of Mercury

rpm: Rounds per minute

CFU: Colony forming unit

O.P.A: Orthophosphoric acid

w/v Weight/Volume