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ans them all corectly in sequence manner first unit 8 9 109

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I can see the questions from all three units. Let me search the medical library for all topics simultaneously.

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The library doesn't have pharmaceutical chemistry/inorganic pharmacy textbooks for these specific topics. I'll answer from comprehensive pharmacognosy/pharmaceutical chemistry knowledge directly, which is well within my training data.Here are all questions answered in sequence — Unit 8, then Unit 9, then Unit 10:

UNIT-VIII — Essential Trace Elements & Antimicrobials

① Very Short Answer (2 Marks)

(i) What are anti-microbial agents? Give examples. Anti-microbial agents are substances that kill or inhibit the growth of microorganisms (bacteria, fungi, viruses). They may be bactericidal or bacteriostatic. Examples: Boric acid, Hydrogen peroxide, Potassium permanganate, Silver nitrate.

(ii) Give the use of Boric acid.

Used as a mild antiseptic and anti-infective for skin and eye infections
Used as eye wash (1.9% solution – isotonic)
Preservative in pharmaceutical preparations
Used as a buffering agent

(iii) Why is sulphuric acid added in the assay of hydrogen peroxide? Sulphuric acid (H₂SO₄) is added to acidify the medium. KMnO₄ (potassium permanganate) used as titrant requires an acidic medium to oxidize H₂O₂. In acidic conditions, KMnO₄ is completely reduced to Mn²⁺, making the endpoint distinct (pink/violet to colourless). Without acidification, incomplete/different reactions occur.

(iv) Write the formal molecular formula of Boric acid. H₃BO₃ (Trihydroxyborane / Orthoboric acid) Molecular weight: 61.83

(v) Write the preparation and use of Iodine.

Preparation: Iodine is obtained from sodium iodide by oxidizing with chlorine or from seaweed. Official preparation is Iodine Solution (Lugol's iodine) – Iodine 5g + KI 10g in 100 mL water.
Uses: Antiseptic for wounds, skin disinfectant, treatment of hyperthyroidism (Lugol's iodine), diagnostic purposes.

(vi) What is the use of glycerine in boric acid assay? Glycerine converts boric acid (a very weak acid, pKa ~9.2) into a stronger mannitoboric acid complex by reacting with the –OH groups of boric acid. This allows its titration with NaOH using phenolphthalein indicator, which would otherwise not give a sharp endpoint.

② Long Answer Type Questions (10 Marks)

(i) [Struck through in image — skipped] Write the principle involved in the preparation and assay principle, medicinal use of Magnesium Sulphate with its chemical formula & synonym.

Magnesium Sulphate (Epsom Salt)

Chemical formula: MgSO₄·7H₂O
Synonym: Epsom salt, Bitter salt
Preparation: Obtained by dissolving magnesium carbonate or oxide in dilute sulphuric acid and crystallizing. MgCO₃ + H₂SO₄ → MgSO₄ + H₂O + CO₂
Assay principle (Complexometric): Dissolve in water, add ammonia buffer (pH 10), indicator Eriochrome Black T; titrate with 0.05 M EDTA (disodium edetate). At endpoint, colour changes from wine-red to blue. Each mL of 0.05 M EDTA = 12.32 mg MgSO₄.
Medicinal uses: Saline cathartic/purgative; anti-convulsant (IV/IM in eclampsia); locally as anti-inflammatory; electrolyte replenisher.

(ii) Write the principle involved in the preparation and assay of Hydrogen Peroxide.

Chemical formula: H₂O₂
Official preparation: 6% w/v solution (≈ 20 volumes). Prepared industrially by auto-oxidation of 2-ethylanthraquinol or electrolysis of H₂SO₄.
Assay principle (Permanganatometry):
- H₂O₂ is dissolved in water + dilute H₂SO₄ (for acidification)
- Titrated with 0.02 M KMnO₄ (standardized)
- Reaction: 2KMnO₄ + 5H₂O₂ + 3H₂SO₄ → 2MnSO₄ + K₂SO₄ + 8H₂O + 5O₂
- Endpoint: Pale pink (permanent) — KMnO₄ itself is the indicator
- Each mL of 0.02M KMnO₄ = 1.701 mg H₂O₂
Uses: Antiseptic, mouthwash (diluted), wound cleansing, bleaching agent, ear wax removal.

(iii) Describe the various mechanisms of action of inorganic anti-microbial agents.

Mechanism	Examples
Protein denaturation/coagulation	Heavy metal salts (Hg, Ag, Zn) — precipitate bacterial proteins
Oxidation of cell constituents	H₂O₂, KMnO₄, Iodine — release nascent oxygen/free radicals
Enzyme inhibition	Hg²⁺, Ag⁺ — block –SH groups of enzymes
Cell membrane disruption	Quaternary ammonium salts, Silver compounds
Halogenation of proteins	Iodine — iodinates tyrosine residues in proteins
Competitive inhibition	Boric acid — interferes with metabolic processes

(iv) What are anti-microbials? Give the method of preparation and principle of assay of Boric acid.

Definition: Anti-microbials are agents that destroy or suppress growth of microorganisms.

Boric Acid (H₃BO₃):

Preparation: Industrial: borax + H₂SO₄ → boric acid Na₂B₄O₇ + H₂SO₄ + 5H₂O → 4H₃BO₃ + Na₂SO₄
Assay Principle (Alkalimetry with glycerine):
1. Dissolve boric acid in hot water
2. Add excess glycerine (forms mannitoboric acid complex → stronger acid)
3. Titrate with 0.1 M NaOH using phenolphthalein indicator
4. Endpoint: Colourless → pink
5. Each mL 0.1 M NaOH = 6.183 mg H₃BO₃
Uses: Eye drops, ear drops, antiseptic dusting powder, skin lotion.

③ Short Answer Type (5 Marks)

(i) What are anti-microbials? Give their mode of action. Enumerate the official antimicrobials.

Anti-microbials destroy or inhibit microbial growth. Modes of action include: oxidation of cell proteins, enzyme inhibition via –SH group blockage, cell wall/membrane disruption, and protein coagulation.

Official antimicrobials (IP):

Boric Acid (H₃BO₃)
Hydrogen Peroxide Solution (H₂O₂)
Iodine (I₂) and Lugol's Iodine
Potassium Permanganate (KMnO₄)
Silver Nitrate (AgNO₃)
Chlorinated Lime (Bleaching Powder — CaOCl₂)
Zinc Sulphate (ZnSO₄)

(ii) Explain the mechanism of action among antimicrobial agents. (See table above under Long Answer iii — mechanisms detailed)

(iii) What is the role of Eriochrome Black T in the assay of Potassium Iodide? In the complexometric assay, Eriochrome Black T (EBT) is used as a metallochromic indicator. At pH ~10 (ammonia buffer), it forms a wine-red coloured complex with metal ions (Mg²⁺/Ca²⁺). On addition of EDTA, EDTA displaces EBT from the metal complex due to stronger binding, releasing free EBT which appears blue — this is the sharp endpoint.

Note: For Potassium Iodide assay specifically, EBT may not be the primary indicator — KI is assayed by iodimetry. However, in the context of trace element/metal assays in the same unit, EBT serves the above role for Mg²⁺/Zn²⁺.

(iv) Write the preparation and use of Chlorinated Lime.

Chemical formula: CaOCl₂ (Calcium hypochlorite + Calcium chloride mixture)
Preparation: Dry slaked lime [Ca(OH)₂] is exposed to chlorine gas at 40°C: 2Ca(OH)₂ + 2Cl₂ → Ca(OCl)₂ + CaCl₂ + 2H₂O
Uses: Disinfection of drinking water, sewage, swimming pools; bleaching of textiles; antiseptic for wounds; disinfecting surgical instruments.

(v) Explain the physiological role of Copper and Chromium.

Copper (Cu):

Cofactor for enzymes: cytochrome c oxidase, superoxide dismutase, tyrosinase
Essential for iron metabolism and haemoglobin synthesis
Required for melanin pigment formation, nerve myelination
Deficiency: Menkes disease, anaemia, hypopigmentation

Chromium (Cr):

Essential trace element — biologically active as Cr³⁺
Functions as a component of Glucose Tolerance Factor (GTF)
Potentiates insulin action — enhances glucose uptake into cells
Involved in lipid and protein metabolism
Deficiency: impaired glucose tolerance, elevated blood lipids

UNIT-IX — Pharmaceutical Aids & Dental Products

① Very Short Answer (2 Marks)

(i) What is dental caries? Name two anti-caries agents. Dental caries is the progressive, microbial destruction of tooth enamel and dentine caused by acids produced from fermentation of dietary sugars by oral bacteria (mainly Streptococcus mutans).

Anti-caries agents:

Sodium fluoride (NaF)
Stannous fluoride (SnF₂)

(ii) What is cleansing agents? Give examples. Cleansing agents are substances that remove dirt, debris, stains, and foreign matter from surfaces (teeth/skin) by physical or chemical action. Examples: Precipitated calcium carbonate (chalk), Sodium lauryl sulphate, Dicalcium phosphate.

(iii) What are dentifrices agents? Give examples. Dentifrices are preparations used for cleaning and polishing teeth, applied with a toothbrush. They may be powders, pastes, or gels. Examples: Toothpaste, Tooth powder, Tooth gel. Key ingredients: Abrasives (calcium carbonate), Detergents (SLS), Fluorides, Binders, Flavours.

(iv) Give two examples for anti-oxidants.

Sodium metabisulphite (Na₂S₂O₅)
Ascorbic acid (Vitamin C) (Others: BHA, BHT, sodium bisulphite)

(v) Differentiate between Water for injection and Sterile water for injection.

Parameter	Water for Injection (WFI)	Sterile Water for Injection (SWFI)
Sterilization	Not sterilized; prepared by distillation	Sterilized by autoclaving after distillation
Container	Bulk containers	Sealed single-dose containers
Pyrogens	Pyrogen-free	Pyrogen-free
Use	Used as vehicle/solvent for preparing injectables	Used directly as diluent for reconstitution
pH	5.0–7.0	5.0–7.0

(vi) Give the chemical formula and use of Bentonite and Magnesium Stearate.

Compound	Chemical Formula	Uses
Bentonite	Al₂O₃·4SiO₂·H₂O (hydrated aluminosilicate)	Suspending agent, emulsifying agent, base for lotions/ointments
Magnesium Stearate	Mg(C₁₇H₃₅COO)₂	Tablet lubricant, glidant, anti-adherent in tablet manufacture

(vii) Give medicinal uses of Calcium Carbonate.

Antacid (neutralizes gastric HCl)
Calcium supplement (osteoporosis, hypocalcemia)
Abrasive in toothpastes/tooth powders
Excipient as diluent in tablets

(viii) Give the chemical formula and use of Sodium meta-bisulphite and Sodium Carboxymethyl Cellulose (CMC).

Compound	Formula	Uses
Sodium metabisulphite	Na₂S₂O₅	Antioxidant/preservative in injections and oral liquids; prevents oxidative degradation
Sodium CMC	[C₆H₇O₂(OH)₂CH₂COONa]ₙ	Viscosity-increasing agent, suspending agent, binder in tablets, laxative

② Long Answer Type Questions (10 Marks)

(i) What are dentifrices? Clarify them with examples. Discuss the role of fluorides in dental caries.

Dentifrices are oral hygiene preparations used with toothbrushes to clean, polish, and protect teeth.

Classification:

Tooth powders – older form; contain abrasives + flavours (calcium carbonate + sodium bicarbonate + flavour oils)
Toothpastes (dental creams) – most common; contain:
- Abrasive: Dicalcium phosphate, Precipitated CaCO₃ (~40–50%)
- Detergent/foaming agent: Sodium lauryl sulphate (~1–2%)
- Binder/thickener: Sodium CMC, carrageenan (~1–2%)
- Humectant: Glycerol, sorbitol (~20–30%)
- Fluoride: Sodium fluoride/sodium monofluorophosphate (~0.1–0.15% F⁻)
- Flavour + sweetener: peppermint oil, saccharin
- Preservative: Sodium benzoate
Tooth gels – transparent, low abrasive, fluoride-rich
Mouthwashes – liquid antiseptic rinses

Role of Fluoride in Dental Caries:

Fluoride (F⁻) is incorporated into the hydroxyapatite of enamel: Ca₁₀(PO₄)₆(OH)₂ + 2F⁻ → Ca₁₀(PO₄)₆F₂ + 2OH⁻
Fluorapatite is more resistant to acid dissolution by bacterial acids
Fluoride also inhibits S. mutans enzyme systems (enolase), reducing acid production
Promotes remineralization of early carious lesions
Systemic fluoride (fluoridated water 0.7–1 ppm) during tooth development strengthens enamel; topical fluoride (toothpaste, gels) provides surface protection

(ii) Enlist the official zinc compounds along with formula and use. Explain the preparation, assay principle and use of any one of them.

Official Zinc Compounds:

Compound	Formula	Use
Zinc sulphate	ZnSO₄·7H₂O	Astringent, eye drops, emetic
Zinc oxide	ZnO	Astringent, mild antiseptic, dusting powder
Zinc chloride	ZnCl₂	Caustic, antiseptic, astringent
Calamine	ZnCO₃ + ZnO	Anti-pruritic lotion, soothing
Zinc undecylenate	Zn(C₁₁H₁₉O₂)₂	Antifungal for tinea pedis

Detailed: Zinc Sulphate (ZnSO₄·7H₂O)

Preparation: Zinc metal or zinc oxide dissolved in dilute sulphuric acid: Zn + H₂SO₄ → ZnSO₄ + H₂ ↑ Or: ZnO + H₂SO₄ → ZnSO₄ + H₂O Crystallized from solution as heptahydrate (white vitriol).
Assay (Complexometric — EDTA titration):
1. Dissolve sample in water
2. Add ammonia buffer (pH 10)
3. Add Eriochrome Black T indicator (wine-red colour)
4. Titrate with 0.05 M Na₂EDTA
5. Endpoint: wine-red → blue
6. 1 mL 0.05 M EDTA ≡ 14.38 mg ZnSO₄·7H₂O
Uses: 0.25% eye drops for conjunctivitis (astringent); systemic zinc supplement; emetic (1–2 g).

(iii) Give the chemical formula, preparation and use of Bentonite and Magnesium Stearate.

Bentonite:

Formula: Al₂O₃·4SiO₂·H₂O (Montmorillonite-type clay)
Preparation: Naturally occurring clay mineral; purified by washing with water, dried at 105°C; not chemically synthesized.
Uses: Suspending agent (2–4%) for insoluble drugs; emulsifying agent (O/W emulsions); base for ointments and lotions; used in clarification of wines/juices.

Magnesium Stearate:

Formula: Mg(C₁₇H₃₅COO)₂
Preparation: Reacting magnesium oxide or magnesium hydroxide with stearic acid under heat: 2C₁₇H₃₅COOH + MgO → Mg(C₁₇H₃₅COO)₂ + H₂O Or by double decomposition of magnesium sulphate + sodium stearate.
Uses: Tablet/capsule lubricant (0.25–1%); prevents sticking of granules to punch faces; glidant; release agent.

(iv) What are anti-caries agents? Give examples. Discuss the role of fluorides in dental caries. (Cross-reference: covered in Long Answer i above — Role of Fluoride section applies here fully.)

Anti-caries agents are substances that prevent or reduce dental caries by one or more mechanisms:

Fluoride compounds: NaF, SnF₂, Na₂PO₃F (sodium monofluorophosphate) — form fluorapatite
Antibacterials: Chlorhexidine (inhibits S. mutans), triclosan
Remineralizing agents: Calcium phosphate systems (CPP-ACP), tricalcium phosphate
Sugar substitutes: Xylitol (non-fermentable by S. mutans)
Sealants: Physical barrier on fissures

③ Short Answer Type (5 Marks)

(i) Discuss the role of fluorides in dental caries. (Covered in detail above — fluorapatite formation, inhibition of S. mutans enolase, remineralization)

(ii) Write the composition and application of Zinc-eugenol cement.

Composition:
- Powder: Zinc oxide (~90%), Zinc stearate (~10%, retarder), White rosin
- Liquid: Eugenol (from clove oil, ~85%), Olive oil (~15%)
Setting reaction: ZnO + eugenol → zinc eugenolate chelate (amorphous matrix)
Applications:
- Temporary dental filling/cement
- Pulp capping agent
- Root canal sealer
- Cavity liner (sedative for pulp — eugenol has anti-inflammatory and analgesic effect)
- Impression paste (surgical pack)

(iii) Give a brief account of fluorine used in dental products. Fluorine used as fluoride ion (F⁻). Official fluoride compounds in dental products:

Sodium fluoride (NaF): 0.05% mouthwash; 1.1% gel for high-risk patients
Sodium monofluorophosphate (Na₂PO₃F): most commonly used in toothpastes (~0.76%)
Stannous fluoride (SnF₂): 0.4% gel; also antibacterial against S. mutans
Acidulated phosphate fluoride (APF): professional topical treatment (1.23% F)
Fluoride at 1 ppm in water reduces caries incidence by ~40–60%

(iv) Enlist the official Zinc compounds along with formula and use. Explain the preparation, assay principle and use of any one of them. (Fully covered in Long Answer ii above)

(v) Write short notes on Pharmaceutical aids. Pharmaceutical aids (excipients) are inert/inactive substances added to a formulation to ensure proper drug delivery, stability, and patient acceptability. Categories include:

Solvents: Purified water, ethanol, propylene glycol
Suspending agents: Bentonite, sodium CMC, tragacanth
Emulsifying agents: Acacia, Tweens, Spans
Antioxidants: Sodium metabisulphite, ascorbic acid
Lubricants: Magnesium stearate, talc
Preservatives: Benzalkonium chloride, phenol
pH adjusters: Buffers (acetate, phosphate, citrate)
Tonicity agents: NaCl, dextrose

(v)[from VSQ] Give the chemical formula and use of Sodium meta-bisulphite and Sodium Carboxymethyl Cellulose. (Covered in Very Short Answer viii above)

(vi) Describe the method of preparation of any two dental products.

1. Compound Sodium Fluoride Toothpaste:

Weigh dicalcium phosphate (abrasive) + glycerol (humectant) + water → mix
Add sodium lauryl sulphate (detergent) → mix
Add sodium CMC (binder) → homogenize
Add sodium fluoride + flavour + preservative → mix to uniform paste
Fill in collapsible tubes

2. Zinc Oxide Eugenol Cement:

Powder (ZnO + rosin) and liquid (eugenol + olive oil) are kept separately
At time of use: Mix powder into liquid on glass slab using spatula in figure-of-8 motion until desired consistency
Setting time: 4–10 minutes at mouth temperature

UNIT-X — Miscellaneous Compounds & Radio Pharmaceuticals

① Very Short Answer (2 Marks)

(i) What are radio-pharmaceuticals? Radio-pharmaceuticals are radioactive compounds used for diagnostic or therapeutic purposes in nuclear medicine. They consist of a radionuclide (radioactive atom) linked to a carrier molecule (drug/biological molecule) that targets specific organs or tissues. Examples: ⁹⁹ᵐTc-sestamibi (heart imaging), ¹³¹I-sodium iodide (thyroid), ¹⁸F-FDG (PET scan).

(ii) Give the importance of radio-isotopes in pharmacy.

Diagnosis: Organ imaging using gamma-emitting isotopes (thyroid scan with ¹³¹I)
Therapy: Targeted radiation therapy of tumours (¹³¹I for thyroid cancer)
Drug research: Radiolabeled drugs used to study pharmacokinetics, absorption, distribution
Sterilization: γ-radiation from ⁶⁰Co used to sterilize heat-sensitive pharmaceutical products
Quality control: Measurement of drug release, bioavailability

(iii) Define Half-life. Half-life (t₁/₂) is the time required for the radioactivity of a radionuclide (or concentration of a drug) to decay/fall to half its original value. For radioactive decay: t₁/₂ = 0.693 / λ (where λ = decay constant) Example: ¹³¹I has t₁/₂ = 8.04 days; ⁹⁹ᵐTc has t₁/₂ = 6 hours.

(iv) Write the use of Sodium Iodide (I¹³¹).

Diagnostic: Thyroid scanning, thyroid uptake studies, detection of thyroid cancer metastases
Therapeutic: Treatment of hyperthyroidism (Graves' disease) — delivers β-radiation to destroy overactive thyroid tissue
Treatment of differentiated thyroid carcinoma (ablation of remnant thyroid tissue post-surgery)

(v) Define Isotope. Isotopes are atoms of the same element (same atomic number Z, same number of protons) but with different mass numbers due to different numbers of neutrons in the nucleus. Example: ¹²⁶I, ¹²⁷I (stable), ¹²⁸I, ¹³¹I (radioactive) are all isotopes of Iodine (Z=53).

(vi) Write the storage conditions of Sodium Iodide.

Stored in a lead-lined container to absorb gamma radiation
Kept at room temperature (not refrigerated unless specified)
Away from light (in amber-coloured sealed containers)
In a radioactive area with proper shielding
Expiry based on radioactive half-life (short shelf-life)
Keep away from children; labelled with radioactive hazard symbol

(vii) Give the precautionary measures for handling of radio-active substances.

Use lead-lined gloves, aprons, goggles (personal protective equipment)
Handle with tongs or remote-control manipulators — never directly
Work behind lead/concrete shields
Use film badge or dosimeter to monitor radiation exposure
Minimize time of exposure (ALARA principle — As Low As Reasonably Achievable)
Store in lead-lined containers in designated radioactive areas
Properly dispose of radioactive waste per regulatory guidelines
Regular monitoring of working area with Geiger-Müller counter

(viii) Write down 2 properties of gamma radiation.

Gamma rays are electromagnetic radiation (high energy photons) with very short wavelength (0.01–10 nm) — no mass, no charge
They have high penetrating power — can penetrate thick materials (requires lead or concrete for shielding); cause ionization of matter

(ix) What are antidotes? Antidotes are agents that counteract the toxic effects of poisons by one or more mechanisms: chemical neutralization, competitive receptor binding, accelerating elimination, or providing a substitute substrate. Examples: Atropine (for organophosphate poisoning), Naloxone (for opioid overdose), N-acetylcysteine (for paracetamol poisoning).

(x) Give one example for respiratory stimulants. Ammonia solution (Aromatic ammonia spirit) — acts as a reflex respiratory stimulant by irritating the mucosa of the upper respiratory tract, triggering the inspiratory reflex. (Other example: Nikethamide / Coramine)

② Long Answer Type Questions (10 Marks)

(i) Explain the role of ammonium compounds as respiratory stimulants.

Ammonia and Ammonium Compounds:

Ammonia (NH₃) is a colourless, pungent gas. In pharmaceutical use, it is mainly used as Aromatic Ammonia Spirit (official IP/BP preparation).

Composition of Aromatic Ammonia Spirit:

Ammonium bicarbonate
Strong ammonia solution (10% NH₃)
Aromatic oils (lemon, lavender, myristica)
Alcohol + water

Mechanism as Respiratory Stimulant:

When inhaled, ammonia vapour irritates the sensory nerve endings of the nasal and pharyngeal mucosa
This triggers a reflex arc via the trigeminal nerve → medullary respiratory center
Results in reflex stimulation of inspiration — deepened, rapid breathing
Also stimulates the vasomotor centre → increased blood pressure
Used in fainting, syncope — the pungent smell revives consciousness reflexively

Other Ammonium Compounds in Pharmacy:

Ammonium chloride (NH₄Cl):
- Expectorant — increases bronchial secretions by reflex; used in cough preparations
- Urinary acidifier — converted to HCl + urea in liver, acidifying urine
Ammonium bicarbonate: component of smelling salts (respiratory stimulant)
Ammonium carbonate: antacid, expectorant

Pharmacological actions:

Respiratory stimulation (reflex)
Expectorant (secretomotor)
Urinary acidification (NH₄Cl)

(ii) What is meant by radioactivity? Write any four clinical applications of radiopharmaceuticals.

Radioactivity: Radioactivity is the spontaneous disintegration (decay) of unstable atomic nuclei with emission of radiation (alpha particles α, beta particles β, gamma rays γ). Discovered by Henri Becquerel (1896). The activity is measured in Becquerel (Bq) — 1 Bq = 1 disintegration/second; older unit: Curie (Ci).

Types of decay:

Alpha (α) decay: emission of ⁴He nucleus; low penetration; used in targeted therapy
Beta (β⁻) decay: emission of electron; moderate penetration; used in therapy (e.g., ¹³¹I)
Gamma (γ) decay: high-energy photon emission; high penetration; used in imaging

Four Clinical Applications of Radiopharmaceuticals:

Application	Radiopharmaceutical	Purpose
Thyroid imaging & therapy	¹³¹I-Sodium iodide	Diagnose/treat hyperthyroidism, thyroid cancer
Cardiac imaging (SPECT)	⁹⁹ᵐTc-sestamibi (Cardiolite)	Assess myocardial perfusion; detect CAD
Bone scanning	⁹⁹ᵐTc-MDP (methylene diphosphonate)	Detect bone metastases, fractures, osteomyelitis
Brain/tumour imaging (PET)	¹⁸F-FDG (fluorodeoxyglucose)	Detect metabolically active tumour cells
Renal imaging	⁹⁹ᵐTc-DTPA / MAG3	Assess renal function and obstruction

(iii) Define radioisotopes with examples and use in pharmacy.

Radioisotopes are isotopes of an element that are radioactive — their nuclei are unstable and spontaneously emit radiation until they reach a stable configuration.

Examples and Uses in Pharmacy:

Radioisotope	Half-life	Emission	Pharmaceutical Use
¹³¹I (Iodine-131)	8.04 days	β + γ	Thyroid imaging, hyperthyroidism therapy
⁹⁹ᵐTc (Technetium-99m)	6 hours	γ only	Most widely used diagnostic agent (bone, heart, brain, kidney)
¹⁸F (Fluorine-18)	110 min	β⁺ (positron)	PET scanning (FDG)
⁶⁰Co (Cobalt-60)	5.27 years	γ	Sterilization of pharmaceuticals and surgical equipment
³²P (Phosphorus-32)	14.3 days	β	Treatment of polycythaemia vera, bone pain palliation
²²⁶Ra (Radium-226)	1600 years	α + γ	Historically used in cancer therapy (now largely replaced)

Uses of radioisotopes in pharmacy:

Diagnostic imaging (scintigraphy, PET, SPECT)
Radiotherapy — targeted tumour treatment
Sterilization — γ irradiation of heat-sensitive formulations
Radiolabelled drug studies — pharmacokinetics, bioavailability, metabolism tracing
Quality control — measurement of drug uniformity, permeability

(iv) Write the types of antidotes. List out the official antidote compounds.

Definition: An antidote is a substance that opposes the toxic action of a poison.

Types of Antidotes:

Type	Mechanism	Example
Chemical antidotes	React chemically to neutralize poison (precipitation, chelation)	EDTA for heavy metals; dimercaprol (BAL) for Hg/As
Physiological/Pharmacological antidotes	Act on receptors to counteract poison's pharmacological effect	Atropine (competitive antagonist) for organophosphates; naloxone for opioids
Mechanical antidotes	Prevent absorption of poison	Activated charcoal (adsorbs toxins); gastric lavage
Universal antidotes	Broad-spectrum action	Activated charcoal + MgO + tannic acid (older concept)
Chelating antidotes	Form non-toxic chelate complexes with metals	EDTA, BAL, D-Penicillamine, Deferoxamine

Official Antidote Compounds:

Antidote	Used For	Mechanism
Atropine sulphate	Organophosphate/carbamate poisoning	Competitive muscarinic receptor antagonist
Pralidoxime (2-PAM)	Organophosphate poisoning	Reactivates acetylcholinesterase
Naloxone (Narcan)	Opioid overdose	Competitive opioid receptor antagonist
N-Acetylcysteine	Paracetamol overdose	Replenishes glutathione; detoxifies NAPQI
Dimercaprol (BAL)	Hg, As, Pb, gold poisoning	Chelating agent (dithiol groups)
Sodium Calcium Edetate (EDTA)	Lead poisoning	Chelates Pb²⁺ → excreted in urine
D-Penicillamine	Cu, Pb, Hg poisoning; Wilson's disease	Chelating agent
Deferoxamine (Desferrioxamine)	Iron poisoning	Chelates Fe³⁺
Vitamin K₁ (Phytomenadione)	Warfarin overdose	Cofactor for clotting factor synthesis
Flumazenil	Benzodiazepine overdose	Competitive BZ receptor antagonist
Fomepizole (4-MP)	Methanol/ethylene glycol poisoning	Inhibits alcohol dehydrogenase
Physostigmine	Atropine/anticholinergic poisoning	Reversible AChE inhibitor
Oxygen (100%)	Carbon monoxide poisoning	Displaces CO from haemoglobin
Sodium thiosulphate + sodium nitrite	Cyanide poisoning	Converts cyanide to thiocyanate (excreted)
Activated charcoal	Multiple oral poisonings	Physical adsorption of toxins

③ Short Answer Type (5 Marks)

(i) Write any four clinical applications of radiopharmaceuticals. (See Long Answer ii table — same four applications apply)

(ii) Define the following terms:

(A) Observed activity: The actual measured radioactivity of a radiopharmaceutical preparation at a given time, recorded by a radiation detector (e.g., ionisation chamber). It is the total count rate observed and may require background correction.

(B) Absolute activity: The true (corrected) activity of a radiopharmaceutical after accounting for background radiation, detector efficiency, geometry, and absorption. Expressed in Becquerels (Bq) or Curies (Ci). Absolute activity = Observed activity ÷ Detector efficiency

(C) Nuclide: A nuclide is any atomic species characterized by a specific number of protons (Z) and neutrons (N) in its nucleus — each unique combination of Z and N is one nuclide. Example: ¹²C, ¹³C, ¹⁴C are three different nuclides of carbon.

(D) Isotope: Isotopes are nuclides of the same element (same Z, same number of protons) but with different numbers of neutrons (different mass number A). Example: ¹²⁷I (stable) and ¹³¹I (radioactive) — both have Z=53, but different neutron numbers.

(iii) What is meant by antidotes? List out the official antidote compounds. (Fully covered in Long Answer iv above — definition + official antidotes table)

All three units are now fully answered. Here's a quick summary of coverage:

Summary of What Was Covered