## STP FOR OFLOXACIN 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.

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 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)      Friability:

The test is applicable to compressed tablets and is intended to determine the physical strength of tablets. Tablets with a unit weight equal to or less than 650 mg, take a sample of whole tablets corresponding as near as possible to 6.5g. For tablets with a unit weight of more than 650mg, take a sample of 10 whole tablets. The tablets should be carefully dedusted prior to testing. Accurately weigh the tablet sample, and place the tablets in the drum. Rotate the drum 100 times and remove the tablets. Remove any loose dust from the tablets as before, and accurately weigh.

The test is run only once unless the results are difficult to interpret or if the weight loss is greater than the target value, in which case, the test is repeated twice and the mean of the three tests is determined.

Formula: initial wt. – after friability wt. x100 / initial wt.

A maximum loss of weight (From a single test or from the mean of three tests) not greater than 1.0 percent is acceptable for most tablets.

9.0)      Dissolution:

Medium: 900ml of 0.1 M Hydrochloric acid

Speed: 50 rpm

Time: 30 minutes

Limit: NLT 80% of the stated amount of Ofloxacin in the medium.

Withdraw a suitable volume of the medium and filter. Measure the absorbance of the filtrate, suitably diluted with the medium if necessary, at the maximum at about 294nm. Calculate the content of Ofloxacin in the medium from the absorbance obtained from a solution of known concentration of Ofloxacin reference standard in the same medium.

10.0)    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.

11.0)    Related substances: Determined by liquid chromatography.

Test solution: Weigh and powder 20 tablets. Weigh a quantity of powdered tablet containing 100mg of Ofloxacin, disperse in 60ml of methanol and dilute to 100 ml with methanol and filter.

Reference solution (a): A 0.1 percent W/V solution of Ofloxacin reference standard in methanol.

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

Chromatographic system:

• A stainless steel column 15 cm X 4.6mm packed with octadecylsilane bonded to porous silica(5µm)
• Mobile phase: a mixture of 8 volumes of acetonitrile and 92 volumes of phosphate buffer prepare by dissolving 2.72 gm of monobasic potassium phosphate in 1000ml of water, adjust to pH 2.4 with O.P.A.
• Flow rate: 2ml per minute
• Spectrometer set at 294nm
• Injection volume: 10µl

Inject reference solution (a). The test is not valid unless the column efficiency is not less than 1400 theoretical plates.

Inject reference solution (b) and the test solution. Run the chromatogram three times of the principal peak. In the chromatogram obtained with the test solution, the area of any secondary peak is not more than the area of the peak in the chromatogram obtained with reference solution (b) (1.0 percent) and the sum of areas 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 percent)

12.0)    Assay: Determined by liquid chromatography.

Test Solution: Weigh and powder 20 tablets. Disperse a quantity of powder containing 25 mg of Ofloxacin in 60ml of methanol and dilute to 100ml with methanol and filter.

Reference solution: A 0.025 percent w/V solution of Ofloxacin in reference standard in methanol.

Chromatographic system:

• A stainless steel column 15 cm X 4.6mm packed with octadecylsilane bonded to porous

silica(5µm)

• Mobile phase: a mixture of 8 volumes of acetonitrile and 92 volumes of phosphate buffer prepare by dissolving 2.72 gm of monobasic potassium phosphate in 1000ml of water, adjust to pH 2.4 with O.P.A.
• Flow rate: 2ml per minute
• Spectrometer set at 294nm
• Injection volume: 10µl

Inject the reference solution. The test is not valid unless the relative standard deviation for replicate injections is not more than 2.0 percent.

Inject the reference solution and the test solution.

Calculate the content of Ofloxacin.

Formula for calculation:

Area of test          Weight of STD                100

—————- X————————- X——————— X Average weight X Potency of STD

Area of STD                 100                      Weight of test

Alternative Method: By UV Spectrophotometer

Test Solution: Weigh and powder 20 tablets. Weight sample equivalent to 50mg of Ofloxacin in 100ml volumetric flask add some 1.0 M HCl into it and sonicate to dissolve the test sample. Make up to mark with 0.1M HCl. Filter and dilute 1ml of this solution to 50ml in same solvent.

Reference Solution: Weigh 50mg of reference standard of Ofloxacin in 100ml of volumetric flask. Add some 0.1 M HCl into it and sonicate to dissolve. Dilute 1ml of this solution to 50ml with same solvent.

Check Absorbance of test as well as reference standard at 294nm in UV Spectrophotometer.

Calculate the content of Ofloxacin.

Formula for calculation:

Absorbance of TEST       STD wt. (mg)                1               100               50        Potency

—————————-X——————–X———X————–X———X———–X Avg. Wt.

Absorbance of STD            100                              50       Test wt (mg)      1           100

Acceptance criteria: 90.0%-110.0%

13.0)    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

HCl: Hydrochloric acid

O.P.A.: Orthophosphoric acid