Tuesday, 29 May 2012

In process QA checks - frequently asked interview questions


Q. How many Tablets shall be taken for checking friability?

Ans:For tablets with unit mass equal or less than 650 mg, take  sample of whole tablets corresponding to 6.5g.For tablets with unit mass more than 650mg,take a sample of 10 whole tablets.

Q. What is the formula for calculating weight loss during friability test?

Ans: %Weight loss =  Initial Weight - Final Weight  X 100
                                                Initial  Weight
Q. What is the pass or fail criteria for friability test?

Ans: Generally the test is run for once.If any cracked,cleaved or broken tablets present in the tablet sample after tumbling,the tablets fails the test.If the results are doubtful,or weight loss is grater than the targeted value,the test should be repeated twice and the mean of the three tests determined.A  mean weight loss from the three samples of not more than 1.0% is considered acceptable for most of the products.

Q. What is the standard number of rotations used for friability test?

Ans: 100 rotations

Q. What is the fall height of the tablets in the friabilator during friability testing?

Ans: 6 inches.Tablets falls from 6 inches height in each turn within the apparatus.

Q. Why do we check hardness during inprocess checks?

Ans: To determine need for the pressure adjustments on the tableting machine.Hardness can affect the disintegration time.If tablet is too hard,it may not disintegrate in the required period of time. And if tablet is too soft it will not withstand handling and subsequent processing such as coating,packing etc.

Q. What are the factors which influence tablet hardness?

Ans: 1.compression force
        2.Binder quantity(More binder more hardness)
        3.Moisture content

Q. Which type of tablets are exempted from Disintegration testing?

Ans: Chewable Tablets

Q. Which capsule is bigger in size - size '0' or size '1'?

Ans: '0' size

Q. What is the recommended temperature for checking DT of a dispersible tablet?

Ans: 25 ±10C (IP) & 15 – 250C (BP)

Q. What is mesh aperture of DT apparatus ?

Ans: 1.8 -2.2mm (#10)

Q. List out the appearance defects of tables during compression activity ?

Appearance Defects
Capping:- ‘Capping’ is the term used, when the upper or lower segment of the tablet separates horizontally, either partially or completely from the main body of a tablet and comes off as a cap, during ejection from the tablet press, or during subsequent handling.
Lamination / Laminating:- Definition: ‘Lamination’ is the separation of a tablet into two or more distinct horizontal layers.

Sticking/filming: ‘ Sticking’ refers to the tablet material adhering to the die wall. Filming is a slow form of sticking and is largely due to excess moisture in the granulation.
Cracking:-  Small fine cracks observed on the upper and lower center surface of the tablets, or very rarely on the side wall are referred to as cracks.
Chipping:- ‘ Chipping’ is defined as the breaking of tablet edges, while the tablet leaves the press or during subsequent handling and coating operation.
Mottling:Mottling’ is the term used to describe an unequal distribution of colour on a tablet.
Double Impression: ‘ Double impression’ involves only those punches,which have a monogram or other engraving on them.

Q. What is the pass/fail criteria for disintegration test?

Ans: If one or two tablets/capsules fails to disintegrate completely, repeat the test on another 12 additional dosage units. The requirement is meet if not fewer than 16 out of 18 tablets/capsules tested are disintegrated completely.

Q. What is the recommended storage conditions for empty hard gelatin capsules?

Ans: 15 - 250C & 35 -55% RH

Q. Which method is employed for checking “Uniformity of dosage unit”?

A.)Content uniformity
B.)    Weight Variation
Weight variation is applicable for following dosage forms;
Hard gelatin capsules,uncoated or film coated tablets,containing 25mg or more of a drug substance comprising 25% or more by weight of dosage unit.

Q. What is the recommended upward and downward movement frequency of a basket-rack assembly in a DT apparatus?

Ans: 28 – 32 cycles per minute.

Q. When performing the ‘uniformity of weight’ of the dosage unit, how many tablet/capsule can deviate the established limit?

Ans: Not more than two of the individual weights can deviates from the average weight by more than the percentage given in the pharmacopeia,and none can deviates more than twice that percentage.
Weight Variation limits for Tablets

80 mg or less
130mg or less
More than 80mg or Less than 250mg
130mg to 324mg
250mg or more
More than 324mg

Weight Variation limits for Capsules

Less than 300mg
300mg or More

Q. What needs to be checked during inprocess QA checks?

a.) Environmental Monitoring
b.) Measured values obtained from the process equipment  (ex:temperature,RPM etc.)
c.) Measured values obtained from persons (ex:timmings,entries etc.)
d.) Process attributes (Ex:weight,hardness,friability etc.)
Q. What precautions shall be taken while collecting  inprocess samples ?

Ans: While collecting inprocess samples, avoid contamination of the product being sampled (Don’t collect samples with bare hands) & avoid  contamination of sample taken.

Q. In a tablet manufacturing facility ‘positive’ pressure is maintained in processing area or service corridors?

Ans: In tablet manufacturing facilities, pressure gradients are maintained to avoid cross contamination of products through air. Usually service corridors are maintained under positive pressure with respect to processing areas.

Q. If sticking observed during tablet compression what may the probable reason for the same?

1.If the granules are not dried properly sticking can occur.
2.Too little or improper lubrication.
3.Too much binder
4.Hygroscopic granular
Q. What checks shall be carried out, while calibrating  DT apparatus?

Ans: While calibrating DT apparatus, following checks shall be performed.
1.)           Number of strokes per minute (Limit:29-32 cycles/min)
2.)           Temperature by probe & standard thermometer
           (Limit:  37 ± 1 OC).
    3).   Distance travelled by basket (Limit:53 -57mm)


Q. What is In process checks?

Ans: In process checks are  checks performed during an activity,In order to monitor and,if necessary,to adjust the process to ensure that product confirms to its specification.

Q. What is the difference between disintegration and dissolution?

Ans: Disintegration is a disaggregation process, in which an oral dosage form falls apart in to smaller aggregates.(Disintegration time is the ‘break up’ time of a solid dosage form).

Where as dissolution is a process by which solid substance enters in the solvent to yield a solution.It is controlled by the affinity between the solid substance and the solvent.

In other word disintegration is a subset of dissolution.
Q. What is the difference between calibration and Validation?

Ans: Calibration is a demonstration that, a particular
Instrument or device produces results with in specified limits by comparisons with those produced by a reference or traceable standard over an appropriate range of measurements.

Where as Validation is a documented program that provides high degree of assurance that a specific process, method or system consistently produces a result meeting pre-determined acceptance criteria.

In calibration performance of an instrument or device is comparing against a reference standard. But in validation such reference standard is not using.

Calibration ensures that instrument or measuring devices producing accurate results. Whereas validation demonstrates that a process, equipment, method or system produces consistent results (in other words, it ensures that uniforms batches are produced).
Q. Why do we calibrate a qualified equipment/instrument on definite intervals?

Ans: An equipment or instrument can ‘drift’ out of accuracy between the time of qualification and actual use.So it is recommended to calibrate and recalibrate the measuring devices and instruments on predetermined time intervals, to gain confidence on the accuracy of the data.

Q. Why do we  consider three consecutive runs/batches for process validation? Why not two or four?

Ans: The number of batches produced in the validation exercise should be sufficient to allow the normal extent of variation and trends to be established and to provide sufficient data for evaluation and reproducibility.
·       First batch quality is accidental (co-incidental),
·       Second batch quality is regular (accidental),
·       Third batch quality is validation(conformation).
In 2 batch we cannot assure the reproducibility of data,4 batches can be taken but the time and cost are involved.

Q. Position of oblong tablets to be placed in hardness tester to determine the hardness? Lengthwise / widthwise?

Ans: Position of oblong tablets should be length wise because the probability of breakage is more in this position.


  1. goog que. n ans


  2. too much helpful. lot of tnx to writer ji.

  3. nice its beter helpful for fresher or newly join a depat.

  4. nice work....it's a basic knowledge que. ans. so, it will helpful to all.
    tnx for good job done.

  5. pls tell me wieght variation for tablet IP

  6. Thnx for valuable information good job sir

  7. sugar coating tablet wt. variation is it exempted ?

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  9. Any reference for selection of number of tablets for test?

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  11. As per which clause we took 20 tablets for friability test is this as per USP?

  12. Why the drum diameter is 6 inch in friabilator?