Pharmaceutical Biotechnology Questions and Answers – Physical and Chemical Instability

This set of Pharmaceutical Biotechnology Multiple Choice Questions & Answers (MCQs) focuses on “Physical and Chemical Instability”.

1. Which of the following causes physical instability in parenteral solution?
a) pH
b) Changes in chemical composition
c) Viscosity
d) Temperature
View Answer

Answer: b
Explanation: Any significant alteration in chemical composition disrupts the physical stability in parenteral solutions. Other factors like Temperature, viscosity and pH causes instability in suspensions.

2. What is the name of the property that describes the process of absorption of moisture by a molecule from the atmosphere?
a) Lipophilicity
b) Hydrophilicity
c) Hygroscopicity
d) Nucleophilicity
View Answer

Answer: c
Explanation: The ability of a molecule to absorb moisture from the surrounding can be determined through Hygroscopicity. Hygroscopic analysis is carried out in order to identify the impact on a molecule’s physical and chemical stability upon moisture absorption.

3. What is the correct abbreviation of DSC?
a) Differential Scan Calorimetry
b) Distinctive Scan Calorimetry
c) Differential Scanning Calorimetry
d) Distinctive Scanning Calorimetry
View Answer

Answer: c
Explanation: The correct abbreviation of DSC is Differential Scanning Calorimetry which is used to analyze the thermal stability of a product. The accurate and highly precise data obtained from DSC is used in determining the physical stability of a product.

4. What phenomenon best characterizes chemical instability?
a) Dissolution
b) Coalescence
c) Precipitation
d) Hydrolysis
View Answer

Answer: d
Explanation: Hydrolysis is one of the mechanisms involved in molecular degradation that characterizes chemical instability, whereas dissolution, coalescence and precipitation characterizes physical instability.

5. Which of the following is a chelating agent?
a) Selenium
c) Polyphenols
d) Lutein
View Answer

Answer: b
Explanation: EDTA is the only chelating agent of the above given options. All the other options are examples of antioxidant agents. Both antioxidants and chelating agents have the tendency to prevent physical and chemical degradation.

6. Which antibiotic is more likely to undergo acid-catalyzed dehydration?
a) Erythromycin
b) Penicillin
c) Oxazepam
d) Cephalosporin
View Answer

Answer: a
Explanation: The antibiotics such as Penicillin, Oxazepam and Cephalosporin undergoes racemization reaction, where the antibiotics go through a transformation process to produce enantiomers. While dehydration occurs in Erythromycin through acid-catalysed reactions.

7. What is the correct abbreviation of TGA?
a) Thermogravimetric Analysis
b) Thermal Gravimetric Analysis
c) Thermo Gravity Analysis
d) Thermal Gravity Analysis
View Answer

Answer: a
Explanation: The proper abbreviation of TGA is Thermogravimetric Analysis. It is a quantitative thermal analysis technique that measures the mass of a sample at different temperatures at regular time intervals.

8. β-D-glucopyranose \(\overset{OH-}{{\leftarrow \rightarrow}}\) D-glucopyranose + D-mannopyranose
What is the name of the above given reaction?
a) Oxidation
b) Racemization
c) Epimerization
d) Decarboxylation
View Answer

Answer: c
Explanation: Epimerization is a process in which an epimer is formed by changing the configuration of one chiral centre. In this reaction, the β-D-glucopyranose is converted into D-glucopyranose (mutarotation) and forms D-mannopyranose (epimer).

9. While upon considering the physical stability of a drug product, which of the following conditions are to be maintained throughout the product’s shelf life?
a) Drug action
b) Sterility and Toxicity
c) Potency
d) Appearance and Uniformity
View Answer

Answer: d
Explanation: Both appearance and uniformity should be maintained necessarily to retain physical stability of a drug product. Along with these conditions pH, disintegration rate and packaging must also be considered based on the product’s nature.

10. Which reaction best describes ester hydrolysis?
a) Acyl-Acid cleavage
b) Reaction with cations
c) Reaction with vacant d-orbitals
d) Reduction of carbon
View Answer

Answer: a
Explanation: During ester hydrolysis, the acyl halides and acid anhydrides undergo cleavage reaction and gives out alcohol and acid as products. Moreover, the process can be catalysed by either an acid or base.

Sanfoundry Global Education & Learning Series – Drug and Pharmaceutical Biotechnology.

To practice all areas of Drug and Pharmaceutical Biotechnology, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

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