TS PGECET 2024 Pharmacy Question Paper with Answer Key PDF

Hydrotrophy is a phenomenon where the solubility of poorly water-soluble compounds is enhanced by the addition of large amounts of additives known as hydrotropic agents. These agents increase solubility by forming weak interactions with the solute without forming micelles, as is the case with surfactants.

This is distinct from solubilization (which involves micelles), co-solvency (which involves miscible solvents), and solid dispersion (which is a solid-state method to enhance solubility).


% Quicktip Quick Tip: Hydrotrophy involves using large quantities of hydrotropic agents (like sodium benzoate) to increase drug solubility without forming micelles.

Clark's formula is a widely used method to calculate the pediatric dose of a medication based on the weight of the child. The formula is:
\[ Child's Dose = \left( \frac{Weight of child in kg}{70} \right) \times Adult Dose \]

This method ensures a weight-based adjustment of the adult dose, assuming the average adult weight is 70 kg. It is more accurate than age-based formulas for children, as weight correlates more directly with drug distribution and metabolism.


% Quicktip Quick Tip: Clark's formula is weight-based: always divide the child's weight in kg by 70 and multiply by the adult dose.

Cetyl trimethyl ammonium chloride is a key conditioning agent widely used in hair care products. It is a quaternary ammonium compound that serves as a cationic surfactant, helping to soften hair, reduce frizz, and improve manageability. It binds to the negatively charged hair strands and provides a conditioning effect.

Other substances listed, like benzyl cinnamate (used in perfumes), ethanol (a solvent), and glycerine (a humectant), do not have the same targeted conditioning properties.


% Quicktip Quick Tip: Look for quaternary ammonium compounds such as cetyl trimethyl ammonium chloride in hair conditioners—they help smoothen and detangle hair effectively.

Hard gelatin capsules typically contain a moisture content in the range of 12–15%. This level is essential for maintaining their mechanical strength and integrity. Lower moisture can make them brittle, while higher moisture may lead to microbial growth or deformation.


% Quicktip Quick Tip: Remember: the ideal moisture content for hard gelatin capsules is between 12–15% to ensure stability and usability.

Aerosol containers are designed to withstand internal pressures ranging from 140 to 180 psi at a high temperature of 130\textdegree F. This standard ensures safety under extreme storage conditions and prevents rupture due to pressure buildup from volatile components inside the container.


% Quicktip Quick Tip: 130\textdegree F is the standard temperature for testing aerosol container pressure tolerance—critical for safety compliance.

Shellac is commonly used in the sealing step of the sugar coating process in tablet formulation. It acts as a moisture barrier and provides a glossy finish. The sealing layer is applied before sub-coating and is critical to maintaining tablet integrity by protecting the core from moisture.


% Quicktip Quick Tip: In sugar coating, Shellac is the go-to sealing agent for its moisture resistance and film-forming properties.

The slugging process is a type of dry granulation method where powders are compressed into large tablets or slugs under high pressure. These slugs are then milled to form granules. It is preferred when the formulation is moisture- or heat-sensitive, eliminating the need for water or heat in granule formation.


% Quicktip Quick Tip: Slugging = Dry granulation. Use when your formulation can't tolerate moisture or heat.

Dry heat sterilization at 250\textdegree C for 45 minutes is the standard method for destroying pyrogens (endotoxins) in parenteral preparations. Pyrogens are heat-stable and cannot be removed by regular sterilization techniques like autoclaving, making high-temperature dry heat the preferred method.


% Quicktip Quick Tip: Remember: 250\textdegree C for 45 minutes is the key condition for pyrogen destruction by dry heat.

During anaerobic glycolysis, glucose is broken down into pyruvate (or lactate in animals), generating 4 ATP molecules, but 2 ATP are consumed during the initial steps. Therefore, the **net ATP gain** is:
\[ Net ATP = 4 - 2 = 2 ATP \]

This process does not involve oxygen and is the primary source of energy in anaerobic conditions.


% Quicktip Quick Tip: Anaerobic glycolysis yields a net gain of 2 ATP per glucose molecule—remember the 2 ATP are consumed early in the process.

Gluconeogenesis is the metabolic process of generating glucose from non-carbohydrate sources. Pyruvate is a key starting substrate in this process. It is converted to oxaloacetate and then to phosphoenolpyruvate, eventually forming glucose. While other intermediates like malate may be involved, pyruvate is the principal substrate.


% Quicktip Quick Tip: Pyruvate is the main precursor for gluconeogenesis—it's the entry point to synthesize glucose when carbohydrate levels are low.

Lipases catalyze the hydrolysis of ester bonds in lipids, converting triglycerides into glycerol and free fatty acids. This class of enzymes is known as **hydrolases**, which function by breaking chemical bonds through the addition of water.


% Quicktip Quick Tip: Lipase = lipid breakdown = hydrolysis → belongs to **hydrolases**.

In humans, purines (adenine and guanine) are ultimately broken down into **uric acid**, which is excreted in urine. Xanthine is an intermediate in this pathway. Uric acid accumulation in the body may lead to gout.


% Quicktip Quick Tip: Remember: Purine → Xanthine → **Uric acid** (end product).

Lipolysis is the breakdown of triglycerides (triacylglycerols) stored in adipose tissue. This process yields **glycerol** and **free fatty acids**. These products can be used for energy production, gluconeogenesis, or β-oxidation.


% Quicktip Quick Tip: Lipolysis: Triacylglycerol → Glycerol + Free fatty acids.

In the early stages of type 2 diabetes, pancreatic beta cells try to compensate for insulin resistance by **increasing insulin secretion**. This hyperinsulinemia helps maintain normoglycemia initially, but over time, beta-cell function declines.


% Quicktip Quick Tip: Early response to insulin resistance = Increased insulin secretion by beta cells.

Variant angina, also called Prinzmetal's angina, is caused by **coronary artery spasm**. Unlike stable angina, it occurs at rest and is due to transient vasoconstriction of coronary arteries, not necessarily related to physical exertion or plaque buildup.


% Quicktip Quick Tip: Variant (Prinzmetal’s) angina = episodic chest pain at rest due to **coronary artery spasm**.

Low-density lipoprotein cholesterol (LDL-C) is known as “bad cholesterol” because it contributes to plaque formation in the arteries, leading to atherosclerosis. Elevated LDL-C levels are a major risk factor for cardiovascular diseases.


% Quicktip Quick Tip: LDL-C = "bad" cholesterol = leads to atherosclerosis.

Prostaglandin F2-alpha (PGF2-α) is a naturally occurring prostaglandin that causes bronchoconstriction. It is involved in the regulation of reproductive functions but can also affect airway tone, especially in asthmatic conditions.


% Quicktip Quick Tip: PGF2-α → think "F" for **forceful contraction**, including bronchoconstriction.

Mutations in the **LRRK2** gene (Leucine-rich repeat kinase 2) are known to cause autosomal dominant forms of Parkinson's disease. It is the most common genetic cause of familial Parkinsonism and also occurs in sporadic cases.


% Quicktip Quick Tip: LRRK2 mutation → most common cause of inherited (autosomal dominant) Parkinson’s disease.

A **Type I error** occurs when the null hypothesis is wrongly rejected—meaning we conclude there is an effect or difference when in reality, there isn’t. This is also known as a “false positive” result.


% Quicktip Quick Tip: Type I error = False positive = Rejected a true null hypothesis.

An **amphiprotic** solvent can both donate and accept a proton. Water is the classic example of such a solvent—it can act as an acid (donating H⁺) and as a base (accepting H⁺), making it amphiprotic.


% Quicktip Quick Tip: Water = amphiprotic = can donate **and** accept H⁺.

Diazotization titration is a specific analytical technique used to quantify **primary aromatic amines**. The amine reacts with nitrous acid to form a diazonium salt, which is the basis for the titration endpoint.


% Quicktip Quick Tip: Diazotization titration = for **primary aromatic amines**, not aliphatic compounds.

Karl Fischer titration, used for water content determination, is based on the **oxidation** of sulfur dioxide by iodine in the presence of water. This reaction helps quantify trace amounts of moisture in pharmaceutical substances.


% Quicktip Quick Tip: Karl Fischer = Oxidation reaction involving iodine and sulfur dioxide to measure water.

**Accuracy** indicates how close the observed value is to the actual or true value. It reflects the correctness of a measurement, while precision relates to repeatability.


% Quicktip Quick Tip: Accuracy = closeness to truth; Precision = repeatability of results.

Cinchona, a plant known for producing quinine, thrives in **acidic soil** with well-drained conditions. Soil pH plays a vital role in nutrient availability for its optimal growth.


% Quicktip Quick Tip: Cinchona prefers **acidic soil** for optimal alkaloid yield.

**Cytokinins** are essential in plant tissue culture as they promote cell division and initiate callus formation. They also work in conjunction with auxins to regulate organogenesis.


% Quicktip Quick Tip: Cytokinins = cell division & callus initiation in plant tissue culture.

The **saponification value** represents the number of milligrams of potassium hydroxide (KOH) required to saponify one gram of fat or oil. It reflects the average molecular weight of all the fatty acids present.


% Quicktip Quick Tip: Saponification value = mg KOH needed to hydrolyze 1g fat/oil.

The **Libermann-Burchard test** is a colorimetric test used to detect **triterpenoid saponins** and steroids. A characteristic color change occurs due to the reaction between acetic anhydride and concentrated sulfuric acid with the compounds.


% Quicktip Quick Tip: Libermann-Burchard test = identification of triterpenoids and steroids.

**Pale catechu** is obtained from the leaves of **Uncaria gambier**. It contains catechin and is used as an astringent. It differs from **black catechu**, which is derived from Acacia catechu.


% Quicktip Quick Tip: Pale catechu → Uncaria gambier; Black catechu → Acacia catechu.

**Curare** is a term for various plant-derived poisons traditionally used on arrows by South American indigenous tribes. It acts as a neuromuscular blocker and is derived mainly from **Chondrodendron tomentosum**.


% Quicktip Quick Tip: Curare = South American arrow poison → muscle relaxant/neuromuscular blocker.

**Fennel (Foeniculum vulgare)** belongs to the **Umbelliferae** (Apiaceae) family. This family is characterized by umbel-shaped flowers and includes many aromatic herbs such as coriander, cumin, and dill.


% Quicktip Quick Tip: Fennel = Umbelliferae family = think “umbrella” flower clusters.

**Cucurbitacins** are highly oxygenated tetracyclic triterpenoids found mainly in plants of the Cucurbitaceae family. They impart bitterness and are known for their cytotoxic properties. **Colocynth** (Citrullus colocynthis) is rich in cucurbitacins.


% Quicktip Quick Tip: Colocynth = source of bitter cucurbitacins (from Cucurbitaceae family).

**European squill** (Urginea maritima) contains cardiac glycosides like scillaren, which are toxic and used as rat poisons. It causes cardiac arrest in rodents and is effective due to its rapid action.


% Quicktip Quick Tip: European squill → cardiac glycoside → rat poison.

**Clove** (Syzygium aromaticum) contains volatile oils with **sesquiterpenoids**, in addition to eugenol, its principal compound. These sesquiterpenoids contribute to the medicinal and aromatic properties of clove.


% Quicktip Quick Tip: Clove = rich in sesquiterpenoids & eugenol (aromatic compound).

**Metoclopramide** exerts its antiemetic effect primarily by **blocking D\textsubscript{2 receptors** in the chemoreceptor trigger zone (CTZ) and **5-HT\textsubscript{3 receptors** in the GI tract and CNS. This dual action reduces nausea and vomiting.


% Quicktip Quick Tip: Metoclopramide = D\textsubscript{2} & 5-HT\textsubscript{3} antagonist → antiemetic.

Class II antiarrhythmic drugs are **beta-blockers**. They act by inhibiting beta-adrenergic receptors, reducing heart rate and myocardial contractility, and are useful in controlling supraventricular arrhythmias.


% Quicktip Quick Tip: Class II = Beta blockers = reduce sympathetic stimulation to the heart.

**Deferoxamine** is a chelating agent that binds to free iron, forming ferrioxamine, which is excreted in urine. It is the treatment of choice in cases of **acute iron poisoning**, especially when serum iron levels are significantly elevated.


% Quicktip Quick Tip: Iron overdose → Deferoxamine chelates iron → renal excretion.

**Propylthiouracil (PTU)** inhibits **thyroid peroxidase**, thereby blocking the iodination of tyrosine residues in thyroglobulin, an essential step in thyroid hormone synthesis. It also inhibits peripheral conversion of T4 to T3.


% Quicktip Quick Tip: PTU blocks thyroid hormone synthesis via thyroid peroxidase inhibition.

**Sulfamethoxazole**, a sulfonamide antibiotic, is known to cause severe hypersensitivity reactions including **Stevens-Johnson syndrome** (SJS), a potentially life-threatening skin reaction.


% Quicktip Quick Tip: SJS risk = Sulfa drugs (e.g., sulfamethoxazole) → skin/mucosal toxicity.

**Macrolides** (e.g., erythromycin) act as **motilin receptor agonists**, which increase gastrointestinal motility. This stimulation of gut smooth muscle contributes to the common side effect of **GI discomfort**.


% Quicktip Quick Tip: Macrolides stimulate motilin receptors → increased GI motility → cramping.

**Neomycin** is an aminoglycoside antibiotic commonly used topically in creams, ointments, and ear drops. Due to its nephrotoxicity and ototoxicity, it is rarely used systemically.


% Quicktip Quick Tip: Neomycin = topical aminoglycoside (skin/ear infections), not for systemic use.

**Ethacrynic acid** is a loop diuretic that is especially known for causing **ototoxicity**, more than other loop diuretics like furosemide. It can lead to hearing loss, particularly when administered in high doses or with other ototoxic drugs.


% Quicktip Quick Tip: Ethacrynic acid = loop diuretic with high ototoxic risk.

**Lorazepam**, a benzodiazepine, is a first-line treatment for **status epilepticus** due to its rapid onset and long duration of action. It enhances GABAergic transmission in the CNS, providing anticonvulsant effects.


% Quicktip Quick Tip: Lorazepam = benzodiazepine used in **status epilepticus**.

**Hydroxyzine** is a first-generation H\textsubscript{1 antihistamine that also exhibits **anxiolytic** (anti-anxiety) properties. It is often used in generalized anxiety disorder and preoperative sedation.


% Quicktip Quick Tip: Hydroxyzine = dual role → antihistamine + anxiolytic.

**Pilocarpine** is a muscarinic agonist that increases the outflow of aqueous humor, thereby lowering intraocular pressure. It is primarily used in the management of **glaucoma**.


% Quicktip Quick Tip: Pilocarpine = muscarinic agonist → lowers IOP in glaucoma.

**Captopril** is an ACE inhibitor that blocks the conversion of angiotensin I to angiotensin II. This leads to vasodilation, reduced aldosterone secretion, and decreased blood pressure.


% Quicktip Quick Tip: Captopril = ACE inhibitor → treats hypertension & heart failure.

**Sumatriptan** is a selective agonist at **5HT\textsubscript{1B/1D receptors**, used primarily in the treatment of acute migraine attacks. Activation of these receptors leads to vasoconstriction of cranial blood vessels and inhibition of pro-inflammatory neuropeptide release.


% Quicktip Quick Tip: Sumatriptan = 5HT\textsubscript{1B/1D} agonist → treats migraines.

**Bambuterol** is a long-acting beta-2 adrenergic agonist and a **prodrug** of **terbutaline**. It undergoes enzymatic conversion in the body, providing prolonged bronchodilation for asthma and COPD management.


% Quicktip Quick Tip: Bambuterol → prodrug of terbutaline → longer action in asthma therapy.

**Isoniazid**, used in tuberculosis treatment, may cause **hepatotoxicity** and **peripheral neuropathy** with long-term use. Pyridoxine (vitamin B6) is co-administered to prevent neuropathy.


% Quicktip Quick Tip: Isoniazid → supplement with B6 to prevent peripheral neuropathy.

The **R-band** (or n to \(\pi^*\) transition) arises when a non-bonding electron is excited to an antibonding \(\pi^*\) orbital. It is commonly observed in carbonyl-containing compounds and is characteristic of UV-visible spectra.


% Quicktip Quick Tip: R-band = \(n \rightarrow \pi^*\) transition (especially in carbonyls).

According to **Woodward-Fieser Rules**, the \(\lambda_{max}\) for a **homo-annular diene** (conjugated double bonds within the same ring) is around **253 nm**. Substituents and auxochromes can further shift this value.


% Quicktip Quick Tip: Homo-annular diene → Woodward-Fieser \(\lambda_{max}\) ≈ 253 nm.

For a non-linear molecule like **H\textsubscript{2O**, the number of vibrational modes is given by:
\[ 3N - 6 = 3(3) - 6 = 3 \]

Hence, H\textsubscript{2O has three vibrational modes: symmetric stretching, asymmetric stretching, and bending.


% Quicktip Quick Tip: Non-linear molecules: Vibrational modes = \(3N - 6\)

Although **nitrogen** is commonly used as a carrier gas in gas chromatography due to its inertness and availability, it has a major disadvantage: **reduced sensitivity** and slower analysis time compared to helium or hydrogen.


% Quicktip Quick Tip: Nitrogen = safe & cheap, but reduces sensitivity in GC.

In **normal phase chromatography**, the stationary phase is polar (e.g., silica), and the mobile phase is **non-polar** (e.g., hexane). This setup separates analytes based on increasing polarity.


% Quicktip Quick Tip: Normal phase: polar stationary + **non-polar mobile** phase.

**Refractive index detectors (RID)** are commonly used in **HPLC** for detecting compounds that lack UV absorption. RID is universal but less sensitive and not compatible with gradient elution.


% Quicktip Quick Tip: HPLC → RID is used for analytes with no UV absorption.

In **electrophoresis**, the mobility of ions is influenced by their **charge, size, and shape**, but **not** by the stationary phase, as this technique doesn't involve one like chromatography does.


% Quicktip Quick Tip: Electrophoresis ≠ chromatography → no stationary phase involved.

In **gel electrophoresis**, the stationary phase is commonly **polyacrylamide gel**. It forms a porous matrix that separates molecules based on size and charge, particularly proteins and nucleic acids.


% Quicktip Quick Tip: Polyacrylamide gel = stationary phase in PAGE (protein separation).

**ELISA** (Enzyme-Linked Immunosorbent Assay) is a widely used analytical technique in **clinical diagnostics** for detecting antigens or antibodies in blood samples. It is vital in disease diagnosis such as HIV, hepatitis, and COVID-19.


% Quicktip Quick Tip: ELISA = diagnostic tool for detecting **antigens/antibodies**.

**Quinhydrone complexes** are examples of **organic molecular complexes**. They involve interactions between electron donors and acceptors like quinone and hydroquinone, forming charge-transfer complexes.


% Quicktip Quick Tip: Organic molecular complexes = Quinhydrone (quinone + hydroquinone).

These polysaccharide-based dispersions (e.g., tragacanth, sodium alginate) show **pseudoplastic flow**—a type of non-Newtonian flow where viscosity decreases with increasing shear rate.


% Quicktip Quick Tip: Pseudoplastic = shear-thinning; flow becomes easier with stirring.

The **Andreasen pipette method** is used to determine the particle size distribution in suspensions within the **0.1–300 µm** range. It works on the sedimentation principle governed by Stoke’s Law.


% Quicktip Quick Tip: Andreasen pipette = sedimentation method for 0.1–300 µm particles.

**Benzalkonium chloride** is a **cationic surfactant** commonly used as a preservative and antimicrobial agent in pharmaceutical formulations. It contains a positively charged quaternary ammonium group.


% Quicktip Quick Tip: Cationic surfactants = quaternary ammonium compounds like benzalkonium chloride.

**Nitrogen mustards** are **bis(β-haloalkyl)amines**, known for their alkylating properties. They form aziridinium ions that react with DNA, making them potent cytotoxic agents used in cancer chemotherapy.


% Quicktip Quick Tip: Nitrogen mustards = Bis β-halo alkyl amines → DNA alkylating agents.

**Cetirizine** is a potent **second-generation H\textsubscript{1 antihistamine**. It provides strong and long-lasting anti-allergic effects with minimal sedative action due to poor penetration of the blood-brain barrier.


% Quicktip Quick Tip: Cetirizine = strong H\textsubscript{1} blocker with less sedation.

**Histamine** contains an **imidazole ring**, a five-membered ring with two nitrogen atoms. This structure is responsible for its biological activity, particularly in allergic and inflammatory responses.


% Quicktip Quick Tip: Histamine = imidazole ring + ethylamine chain → biological activity.

**Warfarin** is a **coumarin-derived anticoagulant** that inhibits vitamin K epoxide reductase, impairing the synthesis of clotting factors II, VII, IX, and X. It is widely used in thromboembolic disorders.


% Quicktip Quick Tip: Warfarin = coumarin anticoagulant → inhibits vitamin K-dependent clotting.

**Digoxin** exerts its action by inhibiting the **Na\textsuperscript{+/K\textsuperscript{+-ATPase** pump in myocardial cells. This leads to an increase in intracellular Na\textsuperscript{+, which subsequently increases intracellular Ca\textsuperscript{2+ via the Na\textsuperscript{+/Ca\textsuperscript{2+ exchanger, enhancing cardiac contractility.


% Quicktip Quick Tip: Digoxin → inhibits Na\textsuperscript{+}/K\textsuperscript{+} pump → more Ca\textsuperscript{2+} → stronger heart contraction.

The **decalin ring** in statins is crucial for their interaction with HMG-CoA reductase. Replacing it with a **cyclohexane ring** significantly reduces hydrophobic binding and leads to a **10000-fold decrease** in inhibitory activity.


% Quicktip Quick Tip: Statins: decalin ring → high affinity; cyclohexane → major activity drop.

**Angiotensin-II** is an **octapeptide** (composed of 8 amino acids). It is a potent vasoconstrictor involved in the renin-angiotensin-aldosterone system, playing a key role in blood pressure regulation.


% Quicktip Quick Tip: Angiotensin-II = 8 amino acids = **octapeptide**

**Chloroquine**, a synthetic antimalarial, is structurally derived from **quinine** by replacing the **6-methoxy group** with a **7-chloro substituent**, which enhances its antimalarial activity and oral efficacy.


% Quicktip Quick Tip: 6-methoxy → 7-chloro switch in quinine → chloroquine synthesis.

**Chloramphenicol**, a broad-spectrum antibiotic, is **synthesized from 4-nitro acetophenone** via a multistep process involving nitro group reduction and further derivatization.


% Quicktip Quick Tip: Chloramphenicol synthesis starts from **4-nitro acetophenone**.

**Azithromycin**, a macrolide antibiotic, contains a **15-membered lactone ring**. This expanded ring (compared to erythromycin's 14-membered ring) improves its acid stability and enhances tissue penetration.


% Quicktip Quick Tip: Azithromycin = 15-membered macrolide ring → better absorption and stability.

**Propranolol**, a basic drug, is absorbed by **ion pair transport**, a process in which the drug forms a neutral complex with an oppositely charged ion to facilitate absorption through the lipid membrane.


% Quicktip Quick Tip: Basic drugs like propranolol → ion pair transport enhances lipid solubility.

Hydrophilic drugs with low molecular weight (like 80 Da) are typically absorbed through **filtration** (also known as paracellular transport), where they pass through water-filled pores between cells.


% Quicktip Quick Tip: Small, hydrophilic drugs → filtration across capillary membranes.

**AUC (Area Under Curve)** represents the total drug exposure over time. It quantifies the **extent of drug absorption** into systemic circulation and is critical in bioavailability and bioequivalence studies.


% Quicktip Quick Tip: AUC = total drug absorbed into systemic circulation over time.

In the first-order elimination equation **dX/dt = – K\textsubscript{EX**, **X** denotes the **amount of drug in the body at any time**. The rate of elimination is directly proportional to this amount.


% Quicktip Quick Tip: In first-order kinetics: X = drug amount; K\textsubscript{E} = elimination rate constant.

**Non-linear pharmacokinetics** refers to drug kinetics where parameters like clearance or half-life change with dose due to saturation of processes such as metabolism or transport. This results in disproportionate changes in drug concentration with increasing dose.


% Quicktip Quick Tip: Non-linear = dose-dependent → saturation of metabolic or transport systems.

**Bioequivalence** is the term used when two or more identical pharmaceutical products show **no significant difference in rate and extent of absorption** when administered in the same molar dose under similar conditions.


% Quicktip Quick Tip: Bioequivalence = same drug release rate and extent → statistically similar AUC and C\textsubscript{max}.

**P-glycoprotein (P-gp)** is an **efflux transporter** found in intestinal epithelium that pumps drugs back into the intestinal lumen, thereby reducing their absorption and bioavailability.


% Quicktip Quick Tip: P-gp = drug efflux pump → reduces absorption → lowers bioavailability.

Clearance, often used in pharmacokinetics and physiology, measures the rate at which a substance (like a drug or waste) is removed from the body, typically by organs like the kidneys or liver. It is defined as the volume of plasma cleared of a substance per unit of time. The standard unit for clearance is liters per hour (L/hour), as it reflects the volume of fluid (in liters) cleared over a period of time (in hours).


Thus, the correct answer is L/hour.



% Quicktip Quick Tip: Clearance is a key concept in understanding how the body processes drugs, often used to calculate dosages in medical settings.

Zidovudine, also known as AZT, is a nucleoside analogue used as an antiretroviral drug to treat HIV. It mimics the structure of thymidine, a nucleoside that is a building block of DNA. Zidovudine is incorporated into viral DNA by HIV's reverse transcriptase enzyme, but it lacks a functional 3'-hydroxyl group, which prevents further DNA chain elongation, thus inhibiting viral replication. It is specifically an analogue of thymidine, not cytidine, purine, or guanosine.


Thus, the correct answer is Thymidine.



% Quicktip Quick Tip: Zidovudine was one of the first drugs approved for HIV treatment and works by interfering with the virus's ability to replicate its genetic material.

Imidazole-containing antifungal drugs are a class of antifungals that have an imidazole ring in their chemical structure. Ketoconazole is a well-known example of an imidazole antifungal, used to treat fungal infections by inhibiting ergosterol synthesis, a key component of fungal cell membranes. Itraconazole and Fluconazole are triazole antifungals, which contain a triazole ring instead. Griseofulvin is not related to imidazoles or triazoles; it works by inhibiting fungal mitosis.


Thus, the correct answer is Ketoconazole.



% Quicktip Quick Tip: Imidazole antifungals like Ketoconazole are often used for topical or systemic fungal infections, but they may have more side effects compared to triazoles.

Amoebiasis is a parasitic infection caused by Entamoeba histolytica. Tinidazole is an antiprotozoal drug commonly used to treat amoebiasis by targeting the parasite and disrupting its DNA synthesis, leading to its death. Tolnaftate is an antifungal, Mefloquine is used for malaria, and Verapamil is a calcium channel blocker used for cardiovascular conditions, none of which are effective against amoebiasis.


Thus, the correct answer is Tinidazole.



% Quicktip Quick Tip: Tinidazole is often preferred over metronidazole for amoebiasis treatment due to its longer half-life and fewer side effects.

Prontosil is historically significant as one of the first synthetic antibacterial drugs. It is a prodrug, meaning it is inactive until metabolized in the body into its active form, sulfanilamide. Sulfanilamide inhibits bacterial growth by interfering with folic acid synthesis, a process essential for bacterial survival. Sulfamethoxazole and Sulfadoxine are other sulfonamides but are not derived from Prontosil, and Nalidixic acid is a quinolone antibiotic, unrelated to this mechanism.


Thus, the correct answer is Sulfanilamide.



% Quicktip Quick Tip: Prontosil, discovered in the 1930s, marked the beginning of the era of sulfonamide antibiotics, revolutionizing bacterial infection treatment.

Nitroglycerin, a vasodilator used to treat angina, is synthesized through the nitration of glycerol. Glycerol, a triol, reacts with nitric acid in the presence of sulfuric acid to form glyceryl trinitrate (nitroglycerin). Glycol, glucose, and glucitol are not suitable precursors for this reaction due to their different chemical structures and functional groups.


Thus, the correct answer is Glycerol.



% Quicktip Quick Tip: Nitroglycerin is highly explosive in its pure form, but in medical use, it is diluted to ensure safety while treating heart conditions.

Procaine is a local anesthetic commonly known as Novocain. Its chemical structure consists of a 4-aminobenzoic acid ester with a diethylaminoethyl group. The IUPAC name for Procaine is 2-(diethylamino)ethyl 4-aminobenzoate, reflecting the diethylamino group attached to the ethyl chain and the 4-aminobenzoate core. The other options contain incorrect substituents, such as dimethyl, triethyl, or dipropyl groups.


Thus, the correct answer is 2-(diethylamino)ethyl 4-aminobenzoate.



% Quicktip Quick Tip: Procaine is often used in dentistry and minor surgeries due to its fast-acting local anesthetic properties.

A \(\beta\)-lactam ring is a four-membered lactam ring in the structure of certain antibiotics, which inhibits bacterial cell wall synthesis. Amoxicillin, a penicillin-class antibiotic, contains a \(\beta\)-lactam ring in its structure, making it effective against a wide range of bacteria. Erythromycin (a macrolide), Vancomycin (a glycopeptide), and Ciprofloxacin (a fluoroquinolone) do not have a \(\beta\)-lactam ring in their structures.


Thus, the correct answer is Amoxicillin.



% Quicktip Quick Tip: The \(\beta\)-lactam ring in antibiotics like Amoxicillin is the target of bacterial resistance mechanisms, such as \(\beta\)-lactamase enzymes.

The cephalosporin nucleus is a core structure of cephalosporin antibiotics, which consists of a \(\beta\)-lactam ring fused to a six-membered dihydrothiazine ring. The \(\beta\)-lactam ring is responsible for the antibacterial activity by inhibiting cell wall synthesis, while the dihydrothiazine ring distinguishes cephalosporins from penicillins (which have a thiazolidine ring). The other options, such as oxazolidine or pyrrole rings, are not part of the cephalosporin structure.


Thus, the correct answer is Beta-lactam ring + Dihydrothiazine ring.



% Quicktip Quick Tip: Cephalosporins are often used as an alternative to penicillins in patients with mild penicillin allergies, though cross-reactivity can occur.

Zaleplon is a non-benzodiazepine hypnotic drug used to treat insomnia. It belongs to the chemical class of pyrazolopyrimidines, characterized by a pyrazole ring fused to a pyrimidine ring in its structure. This class is distinct from imidopyrimidines, imidobenzenes, or cyclopyrrolones, which have different ring systems and are not associated with Zaleplon's structure.


Thus, the correct answer is Pyrazolopyrimidine.



% Quicktip Quick Tip: Zaleplon is often used for short-term insomnia treatment due to its rapid onset and short duration of action.

Diazepam, a benzodiazepine used for anxiety and sedation, is synthesized starting from 2-amino-5-chloro benzophenone. This compound undergoes a series of reactions, including condensation with chloroacetyl chloride and cyclization, to form the benzodiazepine ring structure of Diazepam. Diphenyl methane, 3-chloro acetophenone, and phenothiazine are not precursors in this synthesis pathway.


Thus, the correct answer is 2-Amino-5-chloro benzophenone.



% Quicktip Quick Tip: Diazepam’s synthesis involves forming a seven-membered diazepine ring, which is key to its pharmacological activity.

Amikacin is an aminoglycoside antibiotic, and its potency is often assessed using a microbial bioassay. In this assay, Staphylococcus aureus is commonly used as the test organism because it is sensitive to Amikacin, allowing for accurate measurement of the drug’s antibacterial activity through inhibition zones. Bacillus pumilus, Saccharomyces cerevisiae (a yeast), and Bacillus subtilis are not typically used for Amikacin bioassays.


Thus, the correct answer is Staphylococcus aureus.



% Quicktip Quick Tip: Microbial bioassays measure antibiotic potency by observing the growth inhibition of a sensitive bacterial strain.

**Ethylene oxide (EtO) sterilization** is a chemical method used to sterilize heat- and moisture-sensitive medical equipment and pharmaceuticals. It works by alkylating the DNA and proteins of microorganisms, leading to their death.

Other methods listed (radiation, moist heat, and filtration) are **physical** methods of sterilization.


% Quicktip Quick Tip: Chemical sterilization → think **ethylene oxide** for heat-sensitive tools.

**Yeast extract** is a rich source of **nitrogenous compounds**, **carbon**, **vitamins (especially B-complex)**, and **growth factors** essential for microbial growth. It is commonly used in culture media to support the proliferation of a wide variety of bacteria and fungi.


% Quicktip Quick Tip: Yeast extract = microbial multivitamin → supports robust bacterial growth.

**PABA** competes with sulfonamides for incorporation into folic acid synthesis in bacteria. Because sulfonamides act as PABA analogs, an excess of PABA can inactivate or reduce the effectiveness of sulfonamides.


% Quicktip Quick Tip: Sulfonamides mimic PABA → PABA excess = sulfonamide inactivation.

**Georges Kohler and Cesar Milstein** developed hybridoma technology, which is used to produce **monoclonal antibodies** by fusing antibody-producing B cells with myeloma cells.


% Quicktip Quick Tip: Monoclonal antibodies → Hybridoma → Kohler \& Milstein.

**Passive immunity** involves the transfer of pre-formed antibodies, like **IgG** from mother to fetus via the placenta. It provides immediate, short-term immunity without activating the recipient’s immune system.


% Quicktip Quick Tip: Passive = pre-formed antibodies (e.g. maternal IgG across placenta).

The **BCG (Bacillus Calmette–Guérin)** vaccine is derived from a live, attenuated strain of **Mycobacterium bovis** and is used primarily against **tuberculosis**.


% Quicktip Quick Tip: BCG → Tuberculosis → Live attenuated Mycobacterium bovis.

Pasteurization is a widely used method to inactivate or attenuate pathogens, especially in the production of certain vaccines. It involves controlled heating that kills pathogenic microorganisms while preserving the efficacy of the vaccine. This process ensures that the pathogens cannot cause disease while retaining their immunogenic properties needed to stimulate an immune response.

Other methods like filtration and lyophilization have their roles in vaccine production, but they are not primarily used for inactivating pathogens. Polymerization is a chemical process unrelated to vaccine attenuation.


% Quicktip Quick Tip: Pasteurization is a heat-based method commonly used to weaken or kill pathogens without completely destroying their structure, making them ideal for vaccine formulation.

Clozapine is classified as an atypical antipsychotic drug and is chemically a dibenzodiazepine derivative. It is used in the treatment of resistant schizophrenia and has a distinct mechanism of action compared to typical neuroleptics. Other options listed are not dibenzodiazepine derivatives, and haloperidol is a typical antipsychotic.


% Quicktip Quick Tip: Clozapine is a second-generation antipsychotic that is especially effective in treatment-resistant schizophrenia and is structurally a dibenzodiazepine.

Glipizide is a second-generation sulfonylurea used to treat type 2 diabetes. It stimulates insulin secretion from pancreatic beta cells. The other drugs listed—repaglinide and nateglinide—are meglitinides, and metformin is a biguanide, which works by reducing hepatic glucose production.


% Quicktip Quick Tip: Sulfonylureas like Glipizide lower blood sugar by stimulating insulin release; they are different from meglitinides and biguanides.

Atenolol is a cardioselective beta-blocker that selectively blocks \(\beta_1\) adrenergic receptors. It is used in managing hypertension and angina. The other drugs listed (propranolol, nadolol, timolol) are non-selective beta-blockers that act on both \(\beta_1\) and \(\beta_2\) receptors.


% Quicktip Quick Tip: Atenolol is selective for \(\beta_1\) receptors, making it safer in patients with asthma or COPD compared to non-selective beta-blockers.

The 3-keto group on ring A is a fundamental structural requirement for both glucocorticoid and mineralocorticoid activity. This group plays a crucial role in the binding of these hormones to their respective receptors. Alteration or removal of this group significantly diminishes hormonal activity.


% Quicktip Quick Tip: Both glucocorticoids and mineralocorticoids require a 3-keto group for receptor binding and activity.

Doxycycline is a broad-spectrum antibiotic that belongs to the tetracycline class. It inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit. The other antibiotics belong to different classes: chloramphenicol (amphenicol), streptomycin (aminoglycoside), and erythromycin (macrolide).


% Quicktip Quick Tip: Tetracyclines like doxycycline act by inhibiting the 30S ribosomal subunit and are used to treat a wide range of infections.

According to the Drugs and Cosmetics Act of India, Good Manufacturing Practices (GMP) are covered under Schedule M. It outlines the necessary factory conditions, documentation, and quality control measures required for manufacturing pharmaceuticals.


% Quicktip Quick Tip: Schedule M of the Drugs and Cosmetics Act deals with GMP standards for pharmaceutical manufacturing units.

ISO 14001 is an internationally accepted standard that outlines the requirements for an effective environmental management system (EMS). It helps organizations improve their environmental performance through more efficient use of resources and reduction of waste.


% Quicktip Quick Tip: ISO 14001 = Environmental Management System standard, focused on sustainability and reducing environmental impact.

ICH Q9 guideline is focused on quality risk management in the pharmaceutical industry. It provides principles and tools for risk-based decision-making in quality systems, development, and manufacturing, ensuring better product quality and compliance.


% Quicktip Quick Tip: ICH Q9 emphasizes quality risk management—essential for improving product safety and regulatory compliance.

Schedule Y of the Drugs and Cosmetics Rules, 1945, outlines the requirements and guidelines for clinical trials and the import and manufacture of new drugs in India. It ensures that clinical research is conducted in a scientifically and ethically sound manner.


% Quicktip Quick Tip: Schedule Y is crucial for regulating clinical trials and new drug approvals in India.

Schedule H drugs are prescription drugs that must be sold by retail only on the prescription of a registered medical practitioner. These include antibiotics, hormones, and other potent medications.


% Quicktip Quick Tip: Drugs under Schedule H require a valid prescription for sale to prevent misuse.

Form 12A, under Schedule A of the Drugs and Cosmetics Rules, is used to apply for the import of drugs for personal use. It is specifically meant for individuals, not for commercial or institutional importation.


% Quicktip Quick Tip: Form 12A = Import license form for personal use of drugs under Indian regulation.

Schedule F of the Drugs and Cosmetics Rules specifies the standards for blood banks, including procedures, equipment, and facilities required to collect, store, and supply blood safely.


% Quicktip Quick Tip: Schedule F outlines the rules for operation and maintenance of blood banks in India.

Section 17B of the Drugs and Cosmetics Act defines and deals with spurious drugs. These are drugs that are deliberately mislabeled or misrepresented with the intention to deceive, and pose serious health hazards.


% Quicktip Quick Tip: Spurious drugs are addressed under Section 17B—these are fake or deceptive medicines.

Dried aluminium hydroxide gel is required to contain not less than 47% of aluminium oxide (Al\textsubscript{2O\textsubscript{3) to ensure its efficacy as an antacid. This percentage indicates the active component responsible for its neutralizing properties.


% Quicktip Quick Tip: Aluminium hydroxide gel must contain at least 47% Al\textsubscript{2}O\textsubscript{3} to be pharmaceutically effective.

In the limit test for chlorides, opalescence is produced when chloride ions react with silver nitrate in the presence of nitric acid. This visual change is compared against a standard to determine compliance.


% Quicktip Quick Tip: Opalescence is the characteristic visual indicator in the chloride limit test.

The Indian Pharmacopoeia prescribes a permissible limit of not more than 20 parts per million (ppm) for heavy metals in pharmaceutical substances to ensure safety and avoid toxicity.


% Quicktip Quick Tip: Heavy metal contamination should not exceed 20 ppm as per IP standards.

The Gutzeit test is a sensitive method for detecting arsenic in pharmaceutical substances. It involves converting arsenic into arsine gas and reacting it with mercuric chloride paper to produce a yellow to brown color.


% Quicktip Quick Tip: The Gutzeit method is the standard test for arsenic in pharmacopoeias.

Aluminium phosphate is commonly used as an adsorbent in vaccines to enhance immune response by slowly releasing the toxoid and maintaining its stability. It is particularly used in diphtheria, tetanus, and pertussis vaccines.


% Quicktip Quick Tip: Aluminium phosphate binds toxoids to act as a depot, enhancing vaccine efficacy.

Creatinine kinase (CK), specifically the CK-MB isoenzyme, is released into the blood when there is damage to cardiac muscle, making it a key diagnostic marker for myocardial infarction (heart attack). Other options are not specific indicators for cardiac injury.


% Quicktip Quick Tip: CK-MB is the cardiac-specific enzyme measured in suspected myocardial infarction.

Heart rate of 90 bpm implies 90 beats in 60 seconds. So, the duration of one cardiac cycle is: \[ \frac{60}{90} = 0.67 seconds \]


% Quicktip Quick Tip: Cardiac cycle duration = \( \frac{60}{heart rate in bpm} \)

Methyldopa is the preferred antihypertensive agent in pregnancy due to its safety profile for both mother and fetus. It centrally reduces sympathetic tone without causing significant fetal harm, unlike some beta-blockers or diuretics.


% Quicktip Quick Tip: Methyldopa is safe and effective for managing hypertension in pregnant women.

Catechol-O-methyl transferase (COMT) inhibitors, like entacapone, reduce the peripheral metabolism of L-DOPA, thereby extending its half-life and effectiveness in managing motor fluctuations in Parkinson’s disease.


% Quicktip Quick Tip: COMT inhibitors are adjuncts to L-DOPA that enhance and prolong its therapeutic effect.

Therapeutic drug monitoring (TDM) is not routinely required for metformin as it has a wide therapeutic index and predictable pharmacokinetics. In contrast, drugs like tacrolimus, cyclosporine, and phenytoin have narrow therapeutic windows and require regular monitoring.


% Quicktip Quick Tip: Metformin does not require TDM due to its low toxicity risk at therapeutic doses.