A list of interview questions and answers for pharma jobs

(ARD & QC Part)


Q1. What is Out of specification (OOS)?

is defined as those results of in process or finished product testing that does not comply with the pre-determined acceptance established in drug applications, drug master files (DMFs), official compendia, or by the manufacturer.


Q2. What is Out of trend (OOT)?

result that does not follow the expected trend, either in comparison with previous results with other stability batches or with respect to previous results collected during a stability study.


Q3. What is Bioassay?

is an analytical method to determine the concentration or potency of a substance by its effect on living cells or tissues.


Q4. What is Biomarker?

is defined as a measurable indicator that can be used to a particular disease state or some other biological state of an organism.


Q5. What is Precision?

The precision of an analytical procedure refers to the closeness of agreement between a series of measurements obtained from multiple sampling of the same homogeneous sample under the prescribed conditions.


Q6. What is Robustness?

refer to the ability of an analytical method to remain unaffected by small, but deliberate variations in method parameters and provides an indication of its reliability during normal usage.


Q7. What is TOC?

Total organic carbon (TOC) is a measure of the total amount is of carbon bound in an organic compound and is often used as a non-specific indicator of water quality or cleanliness of pharmaceutical manufacturing equipment.


Q8. How does high performance liquid chromatography (HPLC) work?

High-performance liquid chromatography (sometimes referred to as high-pressure liquid chromatography), HPLC, is a chromatographic technique that can separate a mixture of compounds and is used in biochemistry and analytical chemistry to identify, quantify and purify the individual components of the mixture. HPLC typically utilizes different types of stationary phases contained in columns, a pump that moves the mobile phase and sample components through the column, and a detector to provide a characteristic retention time for the analyte and an area count reflecting the amount of analyte passing through the detector.


Q9. What is the Ultraviolet-Visible (UV) spectrophotometer application?

Ultraviolet–visible spectroscopy or ultraviolet-visible spectrophotometer (UV-Vis or UV/Vis) refers to absorption spectroscopy or reflectance spectroscopy in the ultraviolet-visible spectral region. This means it uses light in the visible and adjacent (near-UV and near-infrared (NIR)) ranges. UV/Vis spectroscopy is routinely used in analytical chemistry for the quantitative determination of different analyses, such as transition metal ions, highly conjugated organic compounds, and biological macromolecules. Determination is usually carried out in solutions.


Q10. What is HLB value? And for which products it’s important?

Hydrophilic-lipophilic balance (HLB) value is a measure of the degree to which it is hydrophilic or lipophilic. It’s help in the selection of a proper surfactant. Especially for emulsion and suspension preparation.

  • HLB value <10 indicate lipid soluble.
  • HLB value >10 indicate water soluble.
  • HLB value 1 to 3 indicates anti-foaming agent.
  • HLB value 3 to 6 indicates W/O emulsifier.
  • HLB value 7 to 9 indicates wetting agent.
  •  HLB value 13 to 16 indicates detergent.
  •  HLB value 8 to 16 indicates O/W emulsifier.


Q11. What is stress testing?

  • Stress testing of the drug substance can help identify the likely degradation of products, which can in turn help establish the degradation pathways and the intrinsic stability of the molecule and validate the stability indicating power of the analytical procedures used.
  • Stress testing is likely to be carried out on a single batch of the drug substance. It should include the effect of temperatures (in 10°C increments (e.g., 50°C, 60°C, etc.) above that for accelerated testing), humidity (e.g., 75% RH or greater)

Q12. What is Viscosity?
The measurement of a materials resistance to flow. Viscosity can determine using a viscometer.

What is Zeta Potential?
is defined as the potential difference between the dispersion medium and the stationary layer of fluid attached to the dispersed particle. The significance of zeta potential is that its value can be related to the stability of colloidal dispersions (e.g., a multivitamin syrup).


Q13. What is Pyrometer?

A pyrometer is a non-contacting device that intercepts and measures thermal radiation, a process known as pyrometry. This device can be used to determine the temperature of an object's surface.

Pyrometer is used for many industrial applications to measure non contact high temperature measurements. This is also useful for temperature measurement of molten iron & steel.



Q14. What is Reference standard?

It is a standardized substance It is used as a measurement base for similar substances. Where the exact active substances of a new drug are not known. A reference standard provides a calibrated level of biological effects against which new preparations of the drug can be compared. Climate chamber: It allows investigation of the effects of a gradient in temperature and relative humidity on a porous structure. It also used in measuring how much water it collects or releases.


Q15. Thin layer chromatography (TLC)

It is a widely employed laboratory technique. It is used for faster and better separations. It is alos for better resolution.


Q16. What is predictable dissolution?

- Predictable dissolution is the in-vitro dissolution study. Which predicts the in-vivo dissolution (drug release) rate?


Q17. Can SLS hamper dissolution?

- Yes, sometimes SLS can hamper the dissolution rate. Especially dissolution rate of gelatin capsule is hampered by SLS. Clarithromycin dissolution rate also hampered by SLS.


Q18. What is Drug Master File (DMF)?
is a document containing complete information on an Active Pharmaceutical Ingredient (API) or finished drug dosage form. It’s may be used to provide confidential detailed information about facilities, processes, or sources used in the manufacturing, processing, packaging, and storing of one or more human drugs. It is known as European Drug Master File (EDMF) or Active Substance Master File (ASMF) and US-Drug Master file (US-DMF) in Europe and United States respectively.


Q19. What are pharmaceutical impurities?
As defined by the United States Pharmacopeial (USP), impurity is “any component of a drug substance that is not the chemical entity defined as the drug substance and in addition, for a drug product, any component that is not a formulation ingredient” 


Q20. What is meant by titration? What are the 4 types of titration?
Titration, process of chemical analysis in which the quantity of some constituent of a sample is determined by adding to the measured sample an exactly known quantity of another substance with which the desired constituent reacts in a definite, known proportion.

4 Types of Titration:
  • Acid-base Titrations.
  • Redox Titrations.
  • Precipitation Titrations.
  • Complexometric Titrations.

Q21. What parameters to be checked for method validation?

  • Selectivity/Specificity
  • Precision
  • Accuracy
  • Linearity
  • Range
  • Stability
  • Limit of Detection (LOD) and Limit of Quantitation (LOQ)

Q22. What do you mean by UPLC?
Ultra Performance Liquid Chromatography (UPLC) is an updated version of HPLC.

Q23. What parameters to be checked for HPLC calibration?

  • Leakage test
  • Flow rate
  • Detector
  • Pump
  • Auto sampler

Q24. What is titrant?

is the solution involved or used in a titration to determine the concentration of an unknown solution.

Q25. What is Potentiometric titration?

is a volumetric method in which the potential between two electrode is measured (referent and indicator electrode).


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