STP FOR LOSARTAN POTASSIUM TABLETS

1.0) Description: Visual

2.0) 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.

Weigh the tablets individually and calculate the percentage of deviation for each tablet. By using formula = (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 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:

            Apparatus: Paddle

Medium: 900ml of water,

Speed: 50 rpm

Time:  45 minutes

            Limit: NLT 80% of the labeled amount of Losartan Potassium is dissolved.

Withdraw a suitable volume of the medium and filter. Measure the absorbance of the filtered solution, suitably diluted with the medium if necessary, at the maximum at about 250nm. Calculate the content of Losartan Potassium in the medium from the absorbance obtained from a solution of known concentration of Losartan potassium reference standard in the same medium.

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 up to 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 substances:

            Determined by liquid chromatography.

Test solution: Weigh and powder 20 tablets. Weigh accurately a quantity of the powdered tablet containing               100mg of losartan potassium, disperse in 100ml of water and filter.

Reference solution (a): A 0.01 per cent w/v solution of Losartan Potassium reference standard in water.

            Reference solution (b): Dilute 1ml of reference solution (a) to 100ml with water.

            Chromatographic system:

  • A stainless steel column 25cm X4.0mm, packed with octylsilane bonded to porous silica (5µm).
  • Mobile phase: a mixture of 75 volumes of buffer solution prepared by mixing 770mg of ammonium acetate in 1000ml water, add 2ml of triethylamine, adjust pH to 6.5 with glacial acetic acid and 25 volumes of acetonitrile,
  • Flow rate: 1.5ml per minute.
  • Spectrophotometer set at 235nm,
  • Injection volume: about 10µl

Inject reference solution (b). Test is not valid unless the tailing factor is not more than 3. And the column efficiency is not less than 1000 theoretical plates.

Inject reference solution (b) and test solution. In the chromatogram obtained with the test solution, the area of any secondary peak is not more than the peak in the chromatogram obtained with reference solution (b) (1.0 per cent) and the sum of area of all the secondary peaks is not more than twice the area of the peak in the chromatogram obtained with the reference solution (b) (2.0 per cent).

11.0)    Assay: Determined by liquid chromatography.

Test solution: Transfer intact tablets in a suitable volumetric flask, dissolve in mobile phase and disperse completely. Dilute with mobile phase to obtain a final concentration of 0.0125 per cent w/v.

            Reference solution: A 0.125 per cent w/v solution of Losartan potassium reference standard in the mobile phase. Dilute 10ml of the solution to 100ml with solvent mixture.

            Chromatographic system:

  • A stainless steel column 25cm X4.0mm, packed with octylsilane bonded to porous silica (5µm).
  • Mobile phase: a mixture of 65 volumes of 0.005 M ammonium acetate, 30 volumes of acetonitrile. 5 volumes of methanol and 0.2 volumes of triethylamine, adjust the pH to 6.6 with glacial acetic acid and filter,
  • Flow rate: 1ml per minute.
  • Spectrophotometer set at 237nm,
  • Injection volume: about 20µl

Inject reference solution. The test is not valid unless the tailing factor is not more than 2.0. The column efficiency is not less than 5000 theoretical plates. The relative standard deviation for replicate injections is not more than 2.0 per cent.

Inject the reference solution and test solution.

Calculate the content of Losartan Potassium 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:

mg: Miligram

ml: Milileter

inHg: Inch of Mercury

rpm: Rounds per minute

CFU: Colony forming unit

w/v: Weight/volume

STP