Category: Drug & Pharmaceutical Biotechnology Objective Questions

Drug Biotechnology Questions and Answers for Aptitude test on “Bioavailability – Methods for Enhancement”.

1. Poor bioavailability means poor aqueous solubility.
a) True
b) False
Answer: a
Clarification: A drug with poor bioavailability means the drug can also have poor aqueous solubility, slow dissolution rate in plasma or other biological fluids. The drug can also have poor stability of the dissolved drug at the patient’s body pH, inadequate partition coefficient, and extensive presystemic metabolism.

2. A drug with poor stability means higher bioavailability.
a) True
b) False
Answer: b
Clarification: Poor stability of the drug at physiological pH causes the difference in its disintegration, dissolution rate thus decreasing the bioavailability. The drug can also have poor stability of the dissolved drug at the patient’s body pH, inadequate partition coefficient, and extensive presystemic metabolism.

3. Which of the following is not an approach for overcoming bioavailability problems?
a) Pharmaceutic approach
b) Pharmacokinetic approach
c) Biologic approach
d) Partition coefficient approach
Answer: d
Clarification: There are three approaches in overcoming the bioavailability problems these are the pharmaceutic approach, pharmacokinetic approach, and biologic approach. The pharmaceutic approach involves modification of formulation, manufacturing processes. The pharmacokinetic approach is in which the pharmacokinetics of the drug is altered by modifying its chemical structure. The biologic approach is where the route of administration can be changed.

4. What will be the particle size after micronization of drugs?
a) 1-10 micron
b) 10-20 micron
c) 20-30 micron
d) 1-5 micron
Answer: a
Clarification: Micronization is a process where the size of the solid drug particles is reduced to 1-10 microns by spray drying or by using air attrition methods. Drugs such as griseofulvin and several steroidal and sulfa drugs are there whose bioavailability is increased by micronization.

5. What is the principle behind the use of surfactants?
a) Reducing the size of solid drug particles
b) Enhancing the dissolution rate by promoting wetting
c) Improving solubility
d) Alter the pH of the microenvironment
Answer: b
Clarification: Surfactants enhance the dissolution rate by promoting wetting and penetration of dissolution fluid into the solid drug particles. These surfactants are used in a concentration below the critical micellar concentration since above CMC the trapped drug in the micelle structure fails to partition in the dissolution fluid.

6. Salts improve solubility and dissolution characteristics.
a) True
b) False
Answer: a
Clarification: Salts improve solubility and dissolution property of the drug in comparison to the original characteristic. Alkali metal salts of acidic drugs and strong acidic salt of the basic drug are more water soluble than the parent drug. For example penicillin and atropine respectively.

7. How pH alteration of the drug microenvironment is done?
a) Altering the pH while the administration
b) In situ salt formation
c) Altering the pH of the tissue
d) Formulating the drug in such a way that it gets activated only when it reaches the tissue pH
Answer: b
Clarification: Alteration of pH of the drug microenvironment is done in two ways. One of that is in-situ salt formation, and other is the addition of buffers to the formulation e.g. buffered aspirin tablets. We cannot depend on tissue pH since it changes person to person.

8. Which one of the following is used for selective adsorption on insoluble carriers of the drugs?
a) Freeze drying
b) Organic solvent
c) Inorganic clays like bentonite
d) Creating metastable polymorphs
Answer: c
Clarification: In the process of selective adsorption on insoluble carriers a highly active adsorbent as the inorganic clays like bentonite can enhance the dissolution rate of poorly aqueous soluble drugs such as indomethacin, it maintains the concentration gradient at its maximum.

9. Which of the following is used in the solvent deposition method of enhancing bioavailability?
a) Freeze drying
b) Organic solvent
c) Inorganic clays like bentonite
d) Creating metastable polymorphs
Answer: b
Clarification: Insolvent deposition method, poorly aqueous soluble drugs are dissolved in an organic solvent such as alcohol and deposited on an inert, hydrophilic, solid matrix such as that of starch or microcrystalline cellulose by evaporation of the solvent.

10. Which of the following is used in solid solutions method of enhancing bioavailability?
a) Highly water-soluble compound
b) Organic solvent
c) Inorganic clays like bentonite
d) Creating metastable polymorphs
Answer: a
Clarification: There are three different ways of solid solutions these are the use of the solid solution, use of eutectic mixtures, and the use of solid dispersions. In all these cases the solute or the drug is most of the times not soluble in water acts as a guest and the solvent used is highly water-soluble compound or polymer acting as a host or carrier.

11. In the below picture which form of solid solution of griseofulvin with succinic acid is shown?

a) Solid solution
b) Eutectic mixture
c) Micronized drug
d) Coarse drug
Answer: a
Clarification: Solid solutions are prepared by fusion method where a mixture of solute and solvent are melted together followed by rapid solidification. Such systems are prepared by fusion and are called as melts e.g. griseofulvin-succinic acid. Solid solution is binary system with solid solute dispersed in solid solvent. Eutectic mixtures are physically blended mixture of two crystalline compound.

12. In the below picture which form of solid solution of griseofulvin with succinic acid is shown?

a) Solid solution
b) Eutectic mixture
c) Micronized drug
d) Coarse drug
Answer: b
Clarification: Solid solutions are prepared by fusion method where a mixture of solute and solvent are melted together followed by rapid solidification. Such systems are prepared by fusion and are called as melts e.g. griseofulvin-succinic acid. Solid solution is binary system with solid solute dispersed in solid solvent. Eutectic mixtures are physically blended mixture of two crystalline compound.

13. In the below picture which form of solid solution of griseofulvin with succinic acid is shown?

a) Solid solution
b) Eutectic mixture
c) Micronized drug
d) Coarse drug
Answer: c
Clarification: Solid solutions are prepared by fusion method where a mixture of solute and solvent are melted together followed by rapid solidification. Such systems are prepared by fusion and are called as melts e.g. griseofulvin-succinic acid. Solid solution is binary system with solid solute dispersed in solid solvent. Eutectic mixtures are physically blended mixture of two crystalline compound.

14. In the below picture which form of solid solution of griseofulvin with succinic acid is shown?

a) Solid solution
b) Eutectic mixture
c) Micronized drug
d) Coarse drug
Answer: d
Clarification: Solid solutions are prepared by fusion method where a mixture of solute and solvent are melted together followed by rapid solidification. Such systems are prepared by fusion and are called as melts e.g. griseofulvin-succinic acid. A solid solution is a binary system with solid solute dispersed in a solid solvent. Eutectic mixtures are physically blended mixture of two crystalline compounds.

15. Which of the following is used in molecular encapsulation of drugs for enhancing bioavailability?
a) Highly water-soluble compound
b) Cyclodextrin
c) Inorganic clays like bentonite
d) Creating metastable polymorphs
Answer: b
Clarification: Beta and gamma Cyclodextrin and other derivatives have the ability to form molecular inclusion complexes with hydrophobic drugs having poor aqueous solubility. These Cyclodextrin molecules have a hydrophobic cavity which can accommodate the lipophilic drugs as a guest. The outside of which is hydrophilic.

Drug Biotechnology for Aptitude test,

Drug Biotechnology online quiz on “Controlled Release Medication – Clinical Trials – 2”.

1. Which of the following country is the most attractive location to perform clinical trials outside the United States?
a) India
b) China
c) United Kingdom
d) Germany
Answer: b
Clarification: China with the largest population has the most clinical trials outside the United States. The United States has the clinical trial records of index 6.88, while China has an index of 6.10. India has a clinical trial index of 5.58. The United Kingdom has the index to be 5.00 and Germany has 4.69.

2. In which phase pharmacodynamics and pharmacokinetics of a drug are studied?
a) Phase I
b) Phase II
c) Phase III
d) Phase IV
Answer: a
Clarification: Phase I trials are the first stage of testing in human subjects. A small (20-50) group of healthy volunteers will be selected. This phase includes trials designed to assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of a drug.

3. What is the full form of SAD?
a) Secure Assessing dose
b) Single Ascending Dose
c) Sodium Ascending Dose
d) Single Amount Dose
Answer: b
Clarification: Single Ascending Dose studies are those in which small groups of subjects are given a single dose of the drug while they are observed and tested for a period of time and MAD is Multiple Ascending Dose studies are conducted to better understand the pharmacokinetics & pharmacodynamics of multiple doses of the drug.

4. What is the full form of MAD?
a) Multiple Ascending Dose
b) Managing Abnormalities Dose
c) Managing absorption dose
d) Managing Assimilation Dose
Answer: a
Clarification: Multiple Ascending Dose studies are conducted to better understand the pharmacokinetics & pharmacodynamics of multiple doses of the drug and SAD is Single Ascending Dose studies are those in which small groups of subjects are given a single dose of the drug while they are observed and tested for a period of time.

5. In which of the phase patients are involved in the trial procedure?
a) Phase I
b) Phase II
c) Phase III
d) Phase IV
Answer: c
Clarification: Phase III studies are randomized controlled trials on large patient groups such as 300–3,000 or more aiming at being the definitive assessment of how effective the drug is, in comparison with at present treatment method in the market. This helps in assessing the benefits and reactions on the patient as well as on the healthy individual.

6. Which of the trial phase is for pharmacovigilance?
a) Phase I
b) Phase II
c) Phase III
d) Phase IV
Answer: d
Clarification: Phase IV trial is also known as Post Marketing Surveillance Trial. Phase IV trials involve safety surveillance (pharmacovigilance) and ongoing technical support of a drug after it receives permission to be sold. Phase 1 consists of research work on a group of 20-50 people. Phase 2 and 3 has a group of 20-300 and 300 to 3000 respectively.

7. Which of the following will not be an ethical step in the clinical trial procedure?
a) Clinical trials are not supervised well
b) Full informed consent is taken
c) Permission from the ethics committee
d) Permission before starting the run trial
Answer: a
Clarification: Clinical trials are always closely supervised by regulatory authorities. All studies that involve a medical or therapeutic intervention on patients must be approved by a supervising ethics committee and after that permission is granted to run the trial further. To be ethical, researchers must obtain the full and informed consent of participating human subjects and the subjects must know what can be the consequences.

8. What is GCP?
a) Good cooperation project
b) Good clinical practice
c) Good cleanliness practice
d) Good Constructor provider
Answer: b
Clarification: Good clinical practice is an international quality standard that is provided by International Conference on Harmonisation (ICH), an international body that defines standards, which governments can transpose into regulations for clinical trials involving human subjects. This includes the protection of human rights and provides assurance of the safety and efficacy of the trials.

9. Which one of the following will come under Scheduled X drugs?
a) Narcotics
b) Injectables
c) Serums
d) Vaccines
Answer: a
Clarification: Medicines in India are regulated by the Central Drugs Standard Control Organization under the Ministry and Family welfare. According to this, all kinds of narcotics drugs come under Schedule X drugs. Such as opium, morphine, codeine, etc. comes under the schedules X drugs.

10. Which one of the following will be under Scheduled H and L drugs?
a) Narcotics
b) Injectable
c) Serums
d) Vaccines
Answer: b
Clarification: Medicines in India are regulated by the Central Drugs Standard Control Organization under the Ministry and Family welfare. According to this all kinds of Injectable, antibiotics, and antibacterial comes under Scheduled H and L drugs. Biological products come under Scheduled C and Cl drugs.

11. Which one of the following will be under Scheduled C and Cl drugs?
a) Narcotics
b) Injectable
c) Antibiotics
d) Vaccines
Answer: d
Clarification: Medicines in India are regulated by the Central Drugs Standard Control Organization under the Ministry and Family welfare. According to this all kinds of Injectable, antibiotics, and antibacterial comes under Scheduled H and L drugs. According to this, all kinds of biological products including serums and vaccines come under Scheduled C and Cl drugs.

12. Which one of the following will be under Scheduled N drugs?
a) Narcotics
b) Injectable
c) List of equipment
d) Vaccines
Answer: c
Clarification: Medicines in India are regulated by the Central Drugs Standard Control Organization under the Ministry and Family welfare. According to this all kinds of equipment for the efficient running of the manufacturing wing, qualified personnel come under scheduled N. According to this all kinds of biological products including serums and vaccines come under Scheduled C and Cl drugs.

13. What is the full form of IND?
a) Investigated drug
b) Investigation Application
c) Investigation of New Drug Application
d) Under Investigation
Answer: c
Clarification: Investigation New Drug Application is when a manufacturing company after lab testing on animals submits the permission seeking the approval of the FDA. FDA reviews IND for about 30 days after that the clinical trials start once the drug is approved.

14. What is the full form of NDA?
a) Investigated drug
b) Investigation Application
c) New Drug Application
d) Under Investigation
Answer: c
Clarification: Once all the trials including phase 1, 2, 3, 4 finishes and all the reports are perfect showing that the drug can be used without any harmful effect the company submits NDA to FDA. FDA reviews NDA and takes almost about 19 months to approve the NDA. Once the NDA is approved the drug can be safely manufactured.

15. GCP include protection of Human rights as a subject in a clinical trial.
a) True
b) False
Answer: a
Clarification: Good Clinical Practice includes protection of human rights as a subject in a clinical trial. It also provides assurance of the safety and efficacy of the newly developed compounds. GCP also includes standards on how clinical trials should be conducted, define the roles and responsibilities of clinical trial sponsors, clinical research investigators, and monitors. In the pharmaceutical industry, monitors are often called Clinical Research Associates.

To practice all areas of Drug Biotechnology for online Quizzes,

Tough Drug Biotechnology Questions and Answers on “Drugs Absorption – Factors Affecting Rate of Drug Dissolution”.

1. Absorption of drugs can be categorized into 2 classes, physicochemical properties of drugs and Dosage form of the drug, on the basis of drug dissolution.
a) True
b) False
Answer: a
Clarification: Factors that are of in vivo importance, those which can affect the drug dissolution and absorption into the cell membrane can be divided into 2 classes. One is the physicochemical properties of the drug and the dosage form factors.

2. Which option will be the best example of the physicochemical properties of drugs?
a) Solubility, particle size, polymorphism, salt form, pseudopolymorphism, complexation, wettability, pH, Pressure of disintegration
b) Pressure of disintegration, polymorphism, salt form, pseudopolymorphism, complexation, wettability, pH
c) Solubility, particle size, polymorphism, salt form
d) Solubility, particle size, polymorphism, salt form, pseudopolymorphism, complexation, wettability
Answer: d
Clarification: The various Physicochemical properties of the drug that affect drug dissolution and its rate are Solubility, particle size, polymorphism, salt form, pseudopolymorphism, complexation, wettability, etc. Dosage form factors include formulation factors and excipients in the formulation.

3. For oral formulation, what should be the minimum aqueous solubility to avoid bioavailability problems?
a) 0.9%
b) 1%
c) 2%
d) 0.11%
Answer: b
Clarification: Experiments have shown that a drug should have a minimum aqueous solubility of 1% to avoid bioavailability problems. Lesser than that it becomes a very serious issue for the drug to dissolve and give the proper effect.

4. The total solid surface area of any particle is known as ___________
a) Absolute surface area
b) Effective surface area
c) Total surface area
d) Surface area
Answer: a
Clarification: Particle size and surface area of a solid drug are inversely related to each other. Absolute surface area is the total area of the solid surface of any particle and an effective surface area is the area of the solid surface exposed to the dissolution medium. Smaller the drug particle greater the surface area.

5. Particle size and surface area of a drug are directly related to each other.
a) True
b) False
Answer: b
Clarification: Particle size and surface area of a solid drug are inversely related to each other. Smaller the drug particle greater the surface area. Larger the area is higher the dissolution rate.

6. Absolute surface area is proportional to the dissolution rate of a drug.
a) True
b) False
Answer: b
Clarification: Absolute surface area is not proportional to the Dissolution rate. Effective surface area is proportional to the dissolution rate. Absolute surface area is the total area of the solid surface of any particle and an effective surface area is the area of the solid surface exposed to the dissolution medium. Effective surface area is the area of the solid surface exposed to the dissolution medium.

7. In the case of hydrophobic drugs, micronization results in a decrease in effective surface area and thus fall is dissolution rate. Which of the below sentences cannot be a reason for the given statement?
a) The hydrophobic surface of the drugs adsorbs onto their surface which inhibits their wettability
b) The particles reaggregate to form larger particles due to their high surface free energy
c) Extreme reduction in the particle size imparts surface charges that may prevent wetting
d) Extreme reduction in the size brings the hydrophobic amino acids to the surface
Answer: d
Clarification: In the case of hydrophobic drugs, micronization results in a decrease in effective surface area and thus fall is dissolution rate. Three reasons are, Hydrophobic surface of the drugs adsorbs onto their surface which inhibits their wettability, the particles reaggregate to form larger particles due to their high surface free energy, extreme reduction in the particle size impart surface charges that may prevent wetting.

8. How the absolute surface area of hydrophobic drugs can be converted to their effective surface area?
a) Use of surfactant
b) Use of Hydrophobic diluents
c) Use of surfactant and hydrophilic diluents
d) No need of doing micronization
Answer: c
Clarification: Use of surfactant as a wetting agent decreases the interfacial tension and displaces the adsorbed air with the solvent and using hydrophilic diluents coat the surface and render them hydrophilic.

9. Which one of these is not an example of hydrophilic diluents?
a) PVC
b) Dextrose
c) PVP
d) PEG
Answer: a
Clarification: PVC is polyvinyl chloride not used as a drug formulation. Hydrophilic diluents such as PEG < PVP, dextrose coat the surface of a hydrophobic molecule to give hydrophilic surface.

10. The solvate can exist in different crystalline forms called as _________
a) Solvates
b) Pseudopolymorphs
c) Pseudopolymorphism
d) Hydrate
Answer: b
Clarification: Stoichiometric type of adducts of the solid where the solvent molecules are incorporated into the crystal lattice of any solid are known as solvates. The solvates that can exist in different crystalline forms are known as pseudopolymorphs. The phenomenon is known as pseudopolymorphism.

11. Which form of a drug has greater solubility?
a) Anhydrous
b) Hydrate
c) Crystallised
d) Monohydrate
Answer: a
Clarification: Anhydrous form of a drug has a greater aqueous solubility than the hydrates. This is because the hydrates are already in interaction with the water and therefore have less energy for crystal breakup.

12. Which one will be the easiest approach to enhance the solubility and dissolution of any drug?
a) Micronize the drug
b) Convert drug into their anhydrous form
c) Convert drug into their hydrous form
d) Convert drug into their salt form
Answer: d
Clarification: Most drugs are weak acids or weak base3s. Thus, one of the easiest approaches to enhance the solubility and dissolution of any drug is to convert them into their salt forms.

13. What is pH?
a) –ve log of H+ concentration
b) +ve log of H+ concentration
c) Log of H+ concentration
d) H+ concentration
Answer: a
Clarification: pH is a scale used to measure how much acidic or basic a solution is. PH is logarithmic and negative of the 10-base logarithm of the molar concentration of the hydrogen ions present.

14. Which one of these is not an advantage of buffered aspirin tablets?
a) Enhanced bioavailability
b) Reduced gastric irritation
c) Increased stability
d) Increased ulcerogenic tendency
Answer: d
Clarification: Including enhanced bioavailability, buffered aspirin tablets have more two advantages that are, reduction of the gastric irritation and ulcerogenic tendency of the drug. And second is the stability is increased by in-situ salt formation.

15. Larger the size of the counterion, greater the solubility.
a) True
b) False
Answer: b
Clarification: The size of the counterion influences the solubility of the salt forms. Smaller the size of the counterion greater the solubility of the salt. If the counter ion has a larger size or poor ionic strength, the solubility decreases to a large extent.

To practice tough questions and answers on all areas of Drug Biotechnology,

Drug Biotechnology Multiple Choice Questions on “Drugs Biotransformation – Phase 2 Reactions”.

1. Which enzyme is important in the Phase II reactions?
a) Esterase
b) Amidases
c) Transferase
d) Aldo-keto-reductases
Answer: c
Clarification: Phase II reactions involve the transfer of a suitable moiety such as glucuronic acid sulfate, glycine, etc. to the phase I reaction. This transfer is mediated by the presence of the enzyme Transferase.

2. The phase II reactions are detoxification pathways.
a) True
b) False
Answer: a
Clarification: In the phase, II reactions tissue reactive and carcinogenic metabolites are rendered harmless by conjugation with glutathione. The Phase II reactions terminate the pharmacologic activity of xenobiotics.

3. Which of the following is not a characteristic of the moieties that are transferred to the substrate in phase II reactions?
a) Simple endogenous molecules are transferred
b) Large molecular sized groups are attached
c) Strong polar groups are attached
d) Strong nonpolar groups are attached
Answer: d
Clarification: The moieties transferred to the substrates in a phase II reactions possess characteristics that are, simple endogenous molecules, large groups, and strong polar or ionic groups are attached to make the substrate water soluble.

4. Which of the following statement is false?
a) D-glucuronic acid is easily available
b) Several functional groups can be easily linked with the D-glucuronic acid
c) Conjugation with D-glucuronic acid occurs to a high degree
d) Whole animal kingdom have the common ability to produce D-glucuronic acid
Answer: d
Clarification: The statement d is false since all the mammals have the ability to produce glucuronides. D-glucuronic acid is readily available and can be easily conjugated with other functional groups.

5. Which coenzyme is synthesized in the 1st step of the formation of Glucuronide?
a) Uridine triphosphate
b) Uridine-5’-diphosphate-alpha-D-glucuronic acid
c) UDP-glucose
d) Glucuronide
Answer: b
Clarification: Glucuronide formation takes place in 2 steps. The 1st step activated coenzyme uridine-5’-diphosphate-alpha-D-glucuronic acid is formed from UDP-glucose. The coenzyme acts as a donor of glucuronic acid.

6. Which enzyme is of the utmost importance for the 2nd step in the formation of Glucuronide?
a) Esterase
b) Amidases
c) Transferase
d) UDP-glucuronyl transferase
Answer: d
Clarification: The moieties transferred to the substrates in a phase II reactions possess characteristics that are, simple endogenous molecules, large groups, and strong nonpolar or ionic groups are attached to make the substrate water soluble.

7. Which one of the following is an example of Carboxyl compounds?
a) Meprobamate
b) Sulfadimethoxine
c) Sulphonamides
d) Salicylic acids
Answer: d
Clarification: These compounds form ester glucuronides. For example aryl acids, arylalkyl acids, salicylic acids, fenoprofen. Amides, Sulfonamides, Meprobamate, Sulfadimethoxine are amines or amides which form N-glucuronides.

8. In the sulfation process, what is the name of the coenzyme formed in the 1st step?
a) 3’-phosphoadenosine-5’-phosphosulfate
b) Adenosine triphosphate
c) Adenosine-5’-phosphosulfate
d) Uridine-5’-diphosphate-alpha-D-glucuronic acid
Answer: a
Clarification: In the 1st step of sulphation, synthesis of an active coenzyme takes place. The coenzyme name is 3’-phosphoadenosine-5’-phosphosulfate. This coenzyme acts as a donor of sulfate to the substrate.

9. Which enzyme’s presence is of utmost importance for the 2nd step of sulphation?
a) Sulfotransferase
b) Amidases
c) Transferase
d) UDP-glucuronyl transferase
Answer: a
Clarification: Sulfotransferase catalyses the transfer of sulphate group from 3’-phosphoadenosine-5’-phosphosulfate to the substrate. It also helps in the liberation of 3’-phosphoadenosine-5’-phosphate.

10. Which of the following is not an example of a drug undergoing acetylation reaction?
a) Hydrazine
b) Salicylic acids
c) Sulphonamides
d) Histamines
Answer: b
Clarification: Acetylation is an important metabolic pathway for drugs containing primary amino groups. Drugs which undergo acetylation reaction are histamine, sulphanilamide, and hydralazine. Acetylation may sometime lead to the production of toxic compounds.

Drug Biotechnology Problems on “Mechanism of Action of Local Anesthetic”.

1. What is the function of local anesthetics?
a) Suppress the activity of the brain
b) Render a specific portion insensitive to pain
c) Suppress the function of a whole organ
d) Make the patient’s full body insensitive to pain
Answer: b
Clarification: Local anesthetics are also called regional anesthetics. Used to render a specific portion of the body insensitive to pain. They interfere with nerve impulse transmission to specific areas of the body. These anesthetics do not cause loss of consciousness.

2. Which of the following is the parenteral application of local anesthetics?
a) When applied to the mucous membrane
b) When applied to the skin
c) When injected to CNS through spinal injection techniques
d) Using ophthalmic drops
Answer: c
Clarification: Parenteral applications are injected to the CNS through various spinal injection techniques. Topical application is applied directly to the skin or mucous membranes. These can be done through creams, solutions, ointments, gels, ophthalmic drops, lozenges, suppositories, etc.

3. Which of the following are natural local anesthetics?
a) Cocaine
b) Benzocaine
c) Benzyl alcohol
d) Clove oil
Answer: a
Clarification: Natural anesthetic is cocaine. Due to its uses in drug abuse, this is not used anymore in practices. Synthetic nitrogenous local anesthetics are procaine, benzocaine, lignocaine, cinchocaine, bucricaine. Synthetic non-nitrogenous will be benzyl alcohol and propanediol. Clove oil, phenol, chlorpromazine can also be used as a local anesthetic.

4. Which of the following is synthetic nitrogenous local anesthetic?
a) Cocaine
b) Benzocaine
c) Benzyl alcohol
d) Clove oil
Answer: b
Clarification: Natural anesthetic is cocaine. Synthetic nitrogenous local anesthetics are derivatives of PABA e.g. procaine, benzocaine, a derivative of acetanilide e.g. lignocaine, a derivative of quinoline e.g. cinchocaine, bucricaine. Synthetic non-nitrogenous will be benzyl alcohol and propanediol. Clove oil, phenol, chlorpromazine can also be used as a local anesthetic.

5. Which of the following is synthetic non-nitrogenous anesthetic?
a) Cocaine
b) Benzocaine
c) Benzyl alcohol
d) Clove oil
Answer: c
Clarification: Natural anesthetic is cocaine. Synthetic nitrogenous local anesthetics are procaine, benzocaine, lignocaine, cinchocaine, bucricaine. Synthetic non-nitrogenous will be benzyl alcohol and propanediol. Clove oil, phenol, chlorpromazine can also be used as a local anesthetic.

6. Apart from natural, synthetic, synthetic non-nitrogenous, which of the following is also a local anesthetic?
a) Cocaine
b) Benzocaine
c) Benzyl alcohol
d) Clove oil
Answer: d
Clarification: Natural anesthetic is cocaine. Due to its uses in drug abuse, this is not used anymore in practices. Synthetic nitrogenous local anesthetics are procaine, benzocaine, lignocaine, cinchocaine, bucricaine. Synthetic non-nitrogenous will be benzyl alcohol and propanediol. Clove oil, phenol, chlorpromazine can also be used as a local anesthetic. Clove oil is being used in dentistry purposes.

7. Which of the following is the pharmacological action of local anesthetics?
a) Reversible block of conduction in nerve
b) Class II antidysrhythmic like action
c) Contraction of smooth muscle
d) Excitation of neuro-muscular transmission in skeletal muscle
Answer: a
Clarification: Pharmacological action by local anesthetics are a reversible block of conduction in nerve, direct relaxation of smooth muscle & inhibition of neuromuscular transmission in skeletal muscle producing vasodilatation. Local anesthetics gives Class I antidysrhythmic like action on the heart.

8. What does membrane expansion theory states?
a) The mechanism is not similar to the general anesthetics
b) Does not rely upon the lipophilic moiety of drugs
c) The molecules of the agent get incorporated into the lipid membrane
d) Causes nerve polarization
Answer: c
Clarification: The membrane expansion theory depends upon the lipophilic moiety of local anesthetics agents. The molecules of the agent get incorporated into the lipid cell membrane which results in the swelling of the membrane. This provides physical obstruction of the sodium channels thus prevents nerve depolarization.

9. What does the specific receptor theory state?
a) Local anesthetics bind to various receptors
b) Produces chemical changes to the receptors
c) Tries to open all the closed sodium gates
d) Binding produces conformational changes
Answer: d
Clarification: Local anesthetics bind to specific receptors within the sodium channel producing physical obstruction to the entry of sodium ions. The act of binding produces conformational changes within the channel. It binds to a closed gate and maintains it in the closed position.

10. Which of the following factor do not affect the absorption of local anesthetics?
a) Vasodilating ability of drug
b) Volume and concentration
c) Vascularity of the tissue
d) Presence of vasodilator
Answer: d
Clarification: Many factors influence the entry of local anesthetic into the circulation some of these are vasodilating ability of the drug, volume, and concentration of the drug, vascularity of the tissues, the route of administration of the drug, the presence of vasoconstrictor.

11. Which is the first local anesthetic?
a) Cocaine
b) Benzocaine
c) Benzyl alcohol
d) Clove oil
Answer: a
Clarification: The first and most potent local anesthetic agent is cocaine though it is rarely used now used because of the problems of misuse. It is unique in it is the ability to produce intense vasoconstriction. The half-life of cocaine is 30 minutes. Dosage of cocaine when used as topical administration 4 – 10% solution of cocaine.

12. Which of the following is being used in dentistry when patients have an allergy from procaine?
a) Cocaine
b) Benzocaine
c) Benzyl alcohol
d) Procaine
Answer: d
Clarification: Procaine is used in dentistry when the patients have proven allergy to the amide group. Used intra-arterially, to treat the arteriospasm which might occur during intravenous sedation. It has excellent vasodilatory properties. The first and most potent local anesthetic agent is cocaine used topically.

13. Which of the following is amide type drug?
a) Lignocaine
b) Cocaine
c) Procaine
d) Benzocaine
Answer: a
Clarification: Benzocaine, procaine, and cocaine are ester type drugs. Procaine is used in dentistry when the patients have proven allergy to the amide group. Lignocaine is an amide-type drug. It is highly lipophilic and rapidly absorbed.

14. Which of the following is topical with high concentration?
a) Lignocaine
b) Cocaine
c) Procaine
d) Benzocaine
Answer: d
Clarification: Used mainly as topical, due to its poor water solubility, and because of its low toxicity, it can be used in concentration up to 20%. Hydrolysed rapidly by plasma esterase to p-aminobenzoic acid accounting for its low toxicity. Lignocaine is an amide-type drug. It is highly lipophilic and rapidly absorbed.

15. Cocaine, when used for local anesthetics, has a half-life of 30 minutes.
a) True
b) False
Answer: a
Clarification: The first and most potent local anesthetic agent, rarely used because of the problems of misuse. It is unique in it is the ability to produce intense vasoconstriction. Cocaine, when used topically for local anesthetic, has a half-life of 30 minutes.

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