Friday, July 16, 2021

Complexometric titration procedure

Learn the complexometric titration procedure used to estimate the hardness of water by the EDTA method.

Titration is a typical quantitative chemical analysis method used in laboratories to determine the concentration of an identified analyte in a given sample solution. Titration is classified into four different types namely acid-base titration, redox titration, precipitation titration, and complexometric titration.

Complexometric titrations are used to determine the concentration of metal ions in sample solutions. Complexometric titration is a type of volumetric method that depends on the formation of a complex between the analyte and the titrant. They generally required the use of complexometric indicators that produce weak complexes with analysis.

Procedure for complexometric titration using EDTA:

Aim:

To determine the amount of total hardness of a given water sample by complexometric titration using EDTA.

Requirements:

Pipette, beaker, conical flask, burette, burette stand, wash bottle, funnel, spatula, eriochrome black T indicator, buffer solution, inhibitor, and standard EDTA Solution (0.01M), etc.

Principle:

The presence of dissolved calcium and magnesium salts in water causes hardness, which is unsuitable for drinking, washing, swimming, and also produces the scales in boilers. Hence, the amount of hardness-producing compounds contained in the water sample must be determined.

The total hardness of water is determined by titrating the sample against EDTA using the indicator of Eriochrome Black-T. Indicator produces a weak EBT Ca2+/Mg2+ wine red colored complex with the Ca2+/Mg2+ ions present in the sample solution. In the presence of ammonia buffer which is a mixture of ammonium chloride and ammonium hydroxide at pH 10, the Ca2+/Mg2+ ions preferentially produce a stable EDTACa2+/Mg2+ complex with EDTA, leaving the Eriochrome Black-T free indicator in solution, which is steel blue in color.

Procedure:

  • Clean and dry all of the equipment.
  • Keep the burette filled with EDTA solution.
  • Using the pipette take 25ml of the given sample and 01 ml of buffer solution in a conical flask.
  • Add 1ml of the inhibitor to the mixture of sample and buffer solution.
  • Now add 2 drops of Eriochrome Black-T indicator to the mixture until the color changes to wine red.
  • Now start titration of the mixture with the standard EDTA solution.
  • The change in color from wine red to blue indicates the endpoint or equivalance point.
  • Repeat the titration three times to obtain three concurrent readings.

Observation table:

Sr.

Volume of water (ml)

Burette Reading (ml)

Volume of EDTA

Initial

Final

Initial

Final

1

 

 

 

2

 

 

 

3

 

 

 

Calculation:

Total hardness = Volume of EDTA solution consumed X 1000 / Volume of the hard water taken= __PPM.

Result:

The total hardness content in a given water sample is__mg/l.


Reference:
http://www.bsauniv.ac.in/UploadImages/Downloads/Estimation%20of%20Hardness.pdf





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Advantages and disadvantages of complexometric titration

Learn the various advantages and disadvantages of complexometric titration.

Titration is the most popular laboratory technique as a quantitative and volumetric method for determining the unknown concentration of a solute in the presence of an indicator by comparing it to the known concentration of a solution. It can be performed in various ways such as acid-base titrations, redox titrations, precipitation titration, and complexometric titrations which depend on the sample and goal.


Complexometric titration (chelatometry) is a type of volumetric analysis used to quantify metal ions by employing complex-formation reactions, in which the evolution of a colored complex is used to define the titration end-point. In complexometric titrations, an indicator is employed to indicate the endpoint or equivalance point of the titration process, which is based on the development of a complex between the analyte and the titrant. This is a useful method for finding the concentration of metal ions and determination of water hardness using EDTA with Eriochrome black-T as the indicator in a sample solution.

The complexometric titration using EDTA can take many types, including direct titration, back titration, replacement titration, and indirect titration, etc. It is used in the pharmaceutical industry, analytical chemistry, environmental analysis, and food analysis to estimate the concentration of metal ions in sample solutions. The visual method and the instrumental method are used to detect the endpoint of a complexometric titration. pH indicators, metallochromic or PM indicators, and redox indicators are examples of visual methods, while photometry and potentiometry are examples of instrumental methods.

Advantages of complexometric titration:

  • The major advantage of complexometric titrations is that they are particularly useful for the determination of mixtures of different metal ions in solution.
  • The reaction can be identifying visually at equilibrium or endpoint.
  • Complexometric titrations can also be performed using instruments that give more accurate results.
  • As it has a simple process, it does not require great expertise, skills, and practice.
  • It is a cost-effective technique since it does not require the use of expensive chemicals, apparatus, and glasswares.

Disadvantages of complexometric titration:

  • The major disadvantage of complexometric titration is that it is a destructive method that often uses relatively large amounts of the substance being analyzed.
  • Since this is an open system, certain factors such as humidity pH, and temperature can affect the results.
  • This can result in a large amount of chemical waste, which must be disposed of.
  • This requires reactions to occur in a liquid phase, which is generally undesirable due to the chemical of interest.

Advantages of using EDTA in complexometric titration?

The advantage of using EDTA in complexometric titration is that it can act as a ligand and can bind to coordination centers, which are generally metals to produce colored complexes.
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Thursday, July 15, 2021

Complexometric titration: Principle, Types, Applications, Indicators, and Example

Complexometric titration is a type of volumetric analysis in that the formation of a colored complex is employed to determine the end-point of the titration. It is primarily used to quantify metal ions by employing complex-formation reactions.

Titration is the most common quantitative and volumetric laboratory technique used to determine the unknown concentration of a solute by comparing it with the known concentration of a solution in the presence of an indicator. 

There are different types of titration when considering goals and processes such as acid-base titrations, redox titrations, precipitation titrations, and complexometric titrations are used, however, redox titration and acid-base titration are the most used types of titration in quantitative chemical analysis.

The required apparatus for titration consists of the beaker, conical flask, funnel, burette, pipette, burette stand, wash bottle, etc. generally they are inexpensive.

What is a complexometric titration give example?

Complexometric titration is also known as chelatometry. Volumetric titrations or analysis in which the endpoints are specified by colored compounds are known as complexometric titrations.

In complexometric titrations an indicator is used that can produce a clear color change in the titration, indicating the titration's endpoint or equivalance point which is dependent on the formation of a complex between the analyte and the titrant. It is very useful for determining the concentration of a mixture of metal ions in the sample solution.

The determination of water hardness using EDTA with Eriochrome black-T as the indicator is one example of complexometric titration.

Principle of complexometric titration:

When the indicator Eriochrome Black T binds with metal ions, it turns wine-red, however, when it is free from metal ions, it remains blue in color. While ethylene diamine tetraacetic acid (EDTA) is colorless regardless of whether it is coupled or not to a metal ion.
complexometric titration

As Eriochrome black T binds to metal ions, adding an EBT indicator to the sample turns it wine-red in color. Eriochrome Black T has loosely binds with metal ions, whereas EDTA has strongly bound with metal ions. Therefore, when all the metal ions are bound to EDTA, the EBT indicator in the sample solution remains free and the solution appears blue.

Types of complexometric titration:

As a chelating titrant, the ethylene diamine tetraacetic acid (EDTA) can be used in different ways. Hence the titrations with EDTA can be performing in different types some of them are as follows.

Direct titration method:

The direct titration method is similar to the acid-base titration technique and is simple and convenient. In this method, the standard EDTA solution is gradually added using a burette to the metal ion solution until the desired endpoint is reached. 

Direct titration is used to determine the copper, mercury, zinc, barium, chromium, aluminum, and lead, etc. in which the solution containing the metal ion to be measured is buffered to the required pH and directly titrated with a standard EDTA solution.

Back titration method:

A back titration is a type of complexometric titration in which the analyte concentration is determined by reacting with a known amount of excess reagent. Metal ions that cannot be directly titrated with EDTA are determined using the back titration method.

Replacement titration method:

The replacement titration method is used when direct titration or back titration fails to produce sharp endpoints. The metal ion is determined by displacing zinc or magnesium ions from an EDTA complex with an equivalent number of metal ions, then titrating the liberated Zn or Mg ion with a standard EDTA solution.

Indirect titration method:

The indirect titration method is commonly used when normal titrations are slow, or the endpoint is difficult to determine, as well as in other applications such as weak acid-weak base reaction. Some anions (For example barium ions) precipitate when they come into contact with metal cations, and these anions do not react with EDTA. Hence, indirect titration with EDTA can be used to determine these types of compounds.

Applications of complexometric titrations:

  • The complexometric titration is used to determine the concentration of metal ions in sample solutions.
  • It is used for the estimation of the amount of calcium present in food products.
  • It is used to find out the total hardness of the water.
  • Complexometric titration is commonly used in the pharmaceutical industries to determine the concentration metal is in a pharmaceutical dosage form (Drug).
  • It is used in analytical chemistry to perform the assay.
  • Complexometric titration is used in environmental analysis to determine bad metals.
  • Cosmetic products are also analyzed by complexometric titration.

Which indicator is used in complexometric titration?

Complexometric indicators are water-soluble organic molecules that play an important role in the titration to indicate the endpoint. These indicators undergo a certain color change in the presence of specific metal ions. Commonly used indicators in complexometric titration are organic dyes which are organic molecules that are soluble in water. When the endpoint is achieved, a color change indicates that the indicator has been displaced from the metal cations in the solution.

Examples of complexometric indicators are Eriochrome Black T, calgamite, arsenazo, xylenol orange, Eriochrome red B, fast sulphon black, and calcein, etc. Eriochrome Black T, which acts as an acid/base indicator as well as a metal ion indicator, is the most often used indicator in complexometric titration.

Methods of endpoint detection in complexometric titration:

The endpoint of the complexometric titration is detected by two methods i.e. visual method and the instrumental method.

Visual method:
The visual method is one of the most popular ways for determining endpoints, because of its advantages, simplicity, cost-effectiveness, and precision. It consists of metallochromic/PM indicators, pH indicators and redox indicators.

Instrumental method:
The instrumental method is also used for determining endpoints of the practical. Instruments are used for complexometric titration such as photometry and potentiometry etc.
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Wednesday, July 14, 2021

Procedure for dissolution test apparatus

Learn how to operate a dissolution test apparatus, which is used to measure the rate at which solid dosage forms dissolve.

The dissolution test is required in the pharmaceutical industries as well as research laboratories to determine the rate of dissolution of solid dosage forms such as tablets, capsules, and caplets, etc. It is one of the quality control tests that is used to evaluate oral dosage form according to different Pharmacopoeias such as USP/BP/IP. The rate and extent of dissolution of a drug are tested in vitro by an appropriate dissolution test. There are different types of dissolution tester are available, the USP apparatus 2 (paddle) is the most commonly used.


Standard operating procedure (SOP) for dissolution test apparatus:

  • Operate the instrument as per the standard operating procedure (SOP).
  • Enter the detail in the logbook kept with the instrument.
  • Ensure the proper connection of the power cord, heater controller cable & external probe to the socket provided on the rear panel.
  • Switch on the instrument.
  • Before performing practical work on the equipment, ensure that the equipment is properly calibrated as per the standards specified in the Pharmacopoeia.
  • Pressing the ‘Lift-up’ provided on the front panel and remove bath top plates & fill the bath with distilled water up to mark level then place the top plate.
  • Keep vessels filled with the required amount of dissolution media (E.g. Buffer solution, generally 900 ml).
  • Install the paddle or basket as per the requirement of the process.
  • Lower the stirrer unit by pressing the 'Down' key from the front panel.
To set the desired parameter:
 RPM setting: Press “RPM” key from front the panel using up (Ù), Down (Ú) and digit scroll (×) key and set desired “RPM” then press the F1 key for rotating the paddle, then press ‘ENTER’ key.
Temperature setting: Press the “TEMP” key from the front panel using the up (Ù), Down (Ú) and digit scroll (×) key. Set the required temperature then press ENTER key.
Sample interval setting: Press the TIME key and set the required value using up (Ù), Down and digit scroll (×) key.
  • For heater ON/OFF press TEMP. Key and F1 key simultaneously then press ENTER key.
  • When starting the heater, the circulating pump is automatically started by default.
  • Press heater on switch also which is provided on the front panel of the temp. The controller is located on the right side of the device.
  • If the Temp reaches the set temp. Then press the START key from the front panel to start the test. It shows the run time screen and the LED on the front panel will glow indicating the temperature run condition.
  • After completing the test, press “STOP” key to stop the test and a halt time will be displayed.
  • Press F1 or F2 key to start or stop the test.
  • Clean the instrument thoroughly and enter the detail in the logbook.

 

Sample withdrawal procedure for dissolution tester:

In the sampling interval, withdraw the sample at the appropriate time and maintain the sink condition by adding a dissolution medium (Buffer/HCl solution). If you are taking samples manually, using pipettes, need to be taken properly. The autosampler is already set up to take the sample from the proper position.

Samples are taken halfway between the top of the paddle or basket and the top of the medium and not less than 1 cm from the vessel wall. Generally, this is taken at an acceptance criteria of ±2%.

Power fail condition:

  • Throughout the process, if power fails, a power failure screen will be displayed when power is resumed.
  • Using the F1 or F2 keys, the user can restart or stop the test.
  • If the F1 key is pressed, the test will start from the point where it stopped and the device will display the run screen again.

Precautions for dissolution apparatus:

  • Before switching ON the heater, ensure that the tank is filled with distilled or purified water without a vessel to the mark of the device.
  • If necessary, change the water in the bath on a weekly or monthly basis.
  • Do not over-tighten the shaft of the paddle or basket, and do not hold or manually stop the paddle or basket while it is in operation.
  • Once the work is done, position the lift at the bottom, not the top of the middle.
  • The physical calibration of the dissolution apparatus should be done every three months, while chemical calibration with prednisolone tablets should be done every six months.

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Sunday, July 11, 2021

Calibration of Dissolution Test Apparatus

The calibration of dissolution apparatus can differ according to different Pharmacopoeias such as USP/BP/IP. According to the USP, the dissolution test consists of four standardized apparatus i.e. basket, paddle, reciprocating cylinder, and flow-through cell. The use of a certain standardized instrument for the drug (active pharmaceutical ingredient) to be analyzed is specified in the monograph.

Dissolution Testing is a quality control test used to evaluate the different dosage forms such as tablets, capsules, suppositories, and pessaries, etc. Every instrument needs to be calibrated for confirming the desired performance as per the standards, the calibration procedure of dissolution test apparatus types 1 and 2 are mentioned in the USP. There are two methods of calibration of dissolution test apparatus such as the physical parameter, and USP tablet calibrator. In physical calibration, check the level adjustment, vibration, shaft rotating speed (RPM), alignment, centering, wobble, depth of paddle/basket, timer, and temperature, etc. In performance verification parameter, dissolution calibration using USP Prednisone calibrator tablets are used with distilled water.


Calibration procedure of dissolution test apparatus:

  • Operate the instrument as per the standard operating procedure (SOP).
  • Materials needed to calibrate: Calibrated Vernier caliper, stopwatch, tachometer, thermometer, prednisone standard, prednisone tablets, water, methanol, Whatman filter paper, glassware, approved kit, and UV-spectrophotometer, etc.

Physical calibration:

Level adjustment of dissolution:

Be sure to level the dissolution test before calibrating using a bubble or spirit level. to adjust the level, rotate the leveling wheel which is provided at the bottom.

Basket calibration of dissolution:

Check each basket's physical characteristics such as the ID of the basket, appearance, external diameter of basket and ring, height, the height of coupling disk, and vent hole diameter, etc. All parameters must be within the range given in the monograph.
Parameter Limit
ID of screen 20.2±1.0 mm
Hole diameter 2.0±0.5 mm
External diameter screen 22.2±1.0 mm
External diameter of ring 25.0±0.02 mm
Total height 37.0 ±3.0 mm
Height of screen 27.0±1.0 mm
Height of coupling disk 5.1±0.5 mm
Distance from bottom 25±2 mm

Paddle calibration of dissolution:

Check each basket's physical characteristics such as paddle height, shaft diameter, upper and lower chord, thickness and distance from the bottom, etc. All parameters must be within the range given in the monograph.
Parameter Limit
ID of screen 20.2±1.0 mm
Hole diameter 2.0±0.5 mm
External diameter screen 22.2±1.0 mm
External diameter of ring 25.0±0.02 mm
Total height 37.0 ±3.0 mm
Height of screen 27.0±1.0 mm
Height of coupling disk 5.1±0.5 mm
Distance from bottom 25±2 mm

Timer calibration of dissolution:

Set a timer for 30 minutes, and turn on the instrument and stopwatch simultaneously, when the instrument is turned off, note the stopwatch reading and note down the observations. The acceptance limit for the timer should not deviate from ± 1 minute.

Spindle speed calibration of dissolution:

Attached the basket or paddle to the instrument and set the 50 RPM. Place the tachometer in contact with each spindle, start the revolution, and take a note of the reading. Or manually count the number of revolutions per minute. Repeat the same process for 100 and 150 RPM alternatively. The standard limit of speed is NMT 4.0 % of set RPM

Wobble test (Shaft of paddle/basket) of dissolution:

Make sure that the paddle/ basket shaft is clean and free of any particle, attached it to the instrument, and lower the apparatus. Place the Wobbling meter in each jar about 2 mm above the paddle/basket, such that the device does not come into contact with the paddle/basket. Operate the machine at 50 RPM and measure the Wobbling of each shaft and basket in mm. The wobbling for paddle/basket as per the USP standard is 2.0 mm.

Paddle/ basket depth calibration of dissolution:

Attached the paddle and basket in each spindle alternatively and lower the apparatus. Place the Vernier caliper/ depth gauge between the bottom of the tool and the bottom of the bowl. Measure the distance from the bottom edge of the paddle blade/basket to the innermost surface of the jar. The standard limit of depth is 25.0± 2mm.

Temperature calibration of dissolution:

Set the temperature of the water bath at 37oC, place the vessels in a water bath, and allow the dissolution medium to come to a temperature of 37oC.Using a calibrated thermometer, check that the temperature of the vessels is within range. Repeat the same procedure for 35, 37, and 40oC. The standard limit of temperature is ± 0.50C.

Chemical calibration:

Calibration of dissolution using prednisone tablets:

Sample: Prednisone tablets (Disintegrating type) 50 mg.
Dissolution medium: 500 ml purified water
Volume: 500 ml
Temperature: 37°C ± 0.5°C
Speed: 50 RPM
Duration: 30 minutes

Procedure for USP type-I dissolution: Set the all above parameters and perform the dissolution test for USP type-I using prednisone tablets (Disintegrating type). Calculate the content of prednisone using the analytical procedure of UV/HPLC at 242 nm. The acceptance criteria for USP type-I at 50 RPM are 45 to 75 % release.

Procedure for USP type-II dissolution: Maintain the same conditions as described under USP type-I and repeat the procedure as in USP type-I, however instead of paddles, use baskets. The acceptance criteria for USP type-I at 50 RPM are 35 to 65 % release.

Calibration of dissolution using salicylic acid tablets:

The calibration of dissolution test equipment using salicylic acid tablets (Non- disintegrating type) has been discontinued.

Why dissolution test apparatus calibration with salicylic acid tablets stopped?

Salicylic acid tablets are unstable and tend to stick together, and as a result, they fail to meet analytical standards. The salicylic acid tablets were therefore withdrawn from the calibration of the dissolution test apparatus.

What is the calibration frequency of the dissolution apparatus?

The physical calibration of the dissolution apparatus takes place every three months, while the chemical calibration takes place every six months.  

ANNEXURES:

Annexure 1: It is a format for recording temperature and rpm calibration data for the dissolution test apparatus.
Annexure 2: It is a format for recording wobble calibration data for the dissolution test apparatus.
Annexure 3: It is a calibration record format of dissolution test apparatus for prednisone tablet and salicylic acid tablet calibration.


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Friday, July 9, 2021

Calibration of disintegration test apparatus

Learn the calibration process of the disintegration test apparatus.

The disintegration testing is an official quality control test for dosage forms such as tablets, capsules, and suppositories used to determine whether a tablet has disintegrated within a specified time when placed in a liquid medium (Water/buffer) under experimental conditions. This testing has sets standards for tablet disintegration testing according to the United States Pharmacopeia (USP).


The apparatus consists of a basket rack holding six plastic tubes that are open at the top and bottom. A wire gauge (10 mesh screen) made of stainless steel is attached to the bottom of the lower plate. The upper and lower plates are placed in vertical metal rods at the periphery and the metal rod in the center of the upper plate is attached to the mechanical device. The rack is immersed in the appropriate liquid at 37°C. It moves up and down at a fixed rate. Each tube contains a sample, and the time it takes for it to disintegrate and fall through the screen is recorded.

How do you calibrate the disintegration apparatus?

  • Operate the instrument as per standard operating procedure (SOP).
  • The frequency of calibration of dissolution test equipment is once a month.

Calibration of the number of cycles:

  • This test requires a pre-calibrated stopwatch. Run the instrument and stopwatch at the same time, and count how many oscillations there are per minute.
  • Repeat the same five times and record the number of oscillations per minute each time in Annexure A.
  • Perform the test individually for both basket rack assembly positions (side A and B).
  • The acceptance limit for oscillations per minute is within the range of 29 to 32 cycles per minute through a distance of 53 to 57 mm.

Calibration of temperature:

  • This test requires a calibrated thermometer.
  • Fill about 800 ml of water in a 1-liter beaker in a water bath and set the bath temperature to 37°C.
  • Connect the basket rack assembly and begin moving up and down at constant frequency.
  • Place the calibrated thermometer into one of the basket rack assembly tubes and wait until the temperature reaches the desired level.
  • Take temperature readings initially and then every 15 minutes for the next 120 minutes.
  • Perform the test individually for both basket rack assembly positions (side A and B).
  • The acceptance limit for temperature is 37± 1°C.

Calibration of distance traveled:

  • This test requires a vernier caliper.
  • Start the instrument and mark the up and down points as soon as the assembly reaches the highest and lowest positions.
  • Start the apparatus and record the value in millimeters (mm) from the up and down positions.
  • Record the value by subtracting the value down-position from the up-position.
  • Perform the test individually for both basket rack assembly positions (side A and B).
  • The acceptance limit for distance traveled by basket (A/B) is between 53-57 mm.

Calibration of timer:

  • This test requires a stopwatch.
  • Set a timer for 15 minutes, and turn on the instrument and stopwatch simultaneously.
  • Immediately note down the stopwatch reading when the apparatus is stopped and note down the observations in annexure A.
  • The acceptance limit for time should not deviate from ±1 min.

Acceptance criteria

Calibration of disintegration test apparatus

Repair/ Maintenance:

If the equipment fails to meet the above requirements should be repaired or serviced by an authorized service engineer. To obtain accurate performance, regular maintenance of the equipment is also required.


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Wednesday, July 7, 2021

Disintegration test procedure for tablets and capsules

Learn the instrumentation and procedure of disintegration test for tablets and capsules dosage forms.

The disintegration test is a quality control test it is performed to evaluate solid dosage forms such as tablets (coated, uncoated, delayed-release enteric-coated), capsules (hard or soft), pessaries, and suppositories, etc. it is used to determine whether the sample is disintegrated within the prescribed time when placed in a liquid medium under the experimental conditions.

There are different quality control tests such as organoleptic, hardness, weight variation, friability, content uniformity, disintegration, and dissolution tests are carried out throughout manufacturing and verified after each batch is completed. They determine whether product quality requirements are met by conducting official or unofficial testing as specified in various pharmacopeias such as the USP, IP, and BP.

Disintegration test apparatus specifications:

The disintegration test apparatus includes a basket-rack assembly, a 1000 ml low-form beaker of 138 to 160 mm in height with an inside diameter of 97 to 115 mm for the immersion liquid, a thermostatic arrangement to maintain the fluid temperature between 35°C and 39°C, and a machine for raising and lowering the basket in the immersion liquid at a constant frequency rate of 29 to 32 cycles per minute.

The quantity of the liquid in the vessel is such that the wire mesh remains at least 15 mm below the surface of the fluid at the highest point of the upward stroke, and lowers to no less than 25 mm from the bottom of the vessel on the downward stroke. The top of the basket-rack assembly should never be submerged. An upward stroke takes the same amount of time as a downward stroke, and the change in stroke direction is a seamless transition rather than a rapid shift in motion. The basket-rack assembly travels vertically along its axis. There is no appreciable horizontal movement or motion of the axis from the vertical.

The disintegration test procedure for tablets and capsules:

Make sure the disintegration test apparatus is properly calibrated before performing the disintegration test procedure.

The disintegration test procedure for coated tablets:

Place one tablet in each tube, suspend the assembly in 0.1 M hydrochloric acid and run for 2 hours without the discs unless otherwise specified in the respective monograph. Remove the assembly from the immersion liquid.

None of the tablets show signs of cracking which allows the contents to escape or disintegrate other than fragments of the coating. Replace the 0.1 M hydrochloric acid with mixed phosphate buffer pH 6.8, add a disc to each tube and run the equipment for another 60 min. Remove the assembly from the immersion liquid. If the tablet fails to comply due to disc adherence, repeat the test on 6 more tablets without the disc.

The disintegration test procedure for uncoated tablets:

Put a sample of dosage unit in each of the six tubes in the basket, along with a disc if prescribed. Run the apparatus using water or a specified medium as the immersion fluid which is maintained at 370C. Lift the basket from the liquid at the end of the time limit stated in the monograph, and inspect the tablets: they have all completely disintegrated. If 1 or 2 tablets have not completely disintegrated, repeat the test on 12 additional tablets. If at least 16 of the total 18 tablets tested have disintegrated, then the criteria are met.

The disintegration test procedure for hard gelatin capsules:

Connect a detachable wire cloth to the surface of the upper plate of the basket-rack assembly, as described under basket-rack assembly that has a simple square weave with 1.8 to 2.2 mm mesh holes and a wire diameter of 0.60 to 0.655 mm. Inspect the capsules within the time limit specified in the individual monograph. All capsules have disintegrated except for fragments from the capsule shell. If 1 or 2 capsules fail to disintegrate completely, take another 12 capsules and repeat the test. Of the total 18 capsules tested, at least 16 capsules completely disintegrate.

The disintegration test procedure for soft gelatin capsules:

To perform the disintegration test on the soft gelatin capsules, follow the instructions for the hard gelatin capsules.


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