← B.Pharm Semester 1

BP102T — General Pharmacy

3 hrs/week · 3 credits · 45 hours · 75 marks (30 internal + 45 end-semester). Notes follow the PCI B.Pharm (NEP 2020) Semester 1 syllabus, unit by unit.

Units in this subject

1. Unit 1 — Introduction to the Profession of Pharmacy
2. Unit 2 — Pharmaceutical Calculations and Dosage Forms
3. Unit 3 — Solid Dosage Forms
4. Unit 4 — Monophasic and Biphasic Liquids
5. Unit 5 — Semisolid Dosage Forms

These are study notes for General Pharmacy (BP102T), B.Pharm first semester. They follow the unit plan exactly: five units, every topic covered, in the order your syllabus lists them. Read a unit, then test yourself with the FAQ at the end of it — those are written the way students actually search and the way examiners actually ask.

Unit I — Introduction to the Profession of Pharmacy

This unit is about where pharmacy came from in India, what pharmacists actually do, the official books that set drug standards (pharmacopoeias), and how to read and handle a prescription. It is memory-heavy but very scoring — most of it comes as short notes and definitions.

History of the Profession of Pharmacy in India

Pharmacy in India did not start with modern colleges. For centuries, medicines came from Ayurveda, Unani and Siddha systems, prepared by vaidyas and hakims. Modern (allopathic) pharmacy entered with the British, and the profession grew in three parallel tracks: education, industry, and professional organisations.

Key milestones to remember (in order):

• 1899 — Acharya P.C. Ray founded the Bengal Chemical and Pharmaceutical Works in Calcutta. This is treated as the birth of the Indian pharmaceutical industry.
• 1901 — Alembic Chemical Works set up at Baroda.
• 1937 — The first B.Pharm course in India started at Banaras Hindu University (BHU), Varanasi. This is the single most-asked date in this topic.
• 1940 — The Drugs and Cosmetics Act was passed, bringing manufacture and sale of drugs under legal control.
• 1948 — The Pharmacy Act was passed and the Pharmacy Council of India (PCI) was constituted. PCI regulates pharmacy education and the registration of pharmacists.
• 1955 — First edition of the Indian Pharmacopoeia (IP) published.

Organisations you should know:

• PCI (Pharmacy Council of India) — statutory body under the Pharmacy Act, 1948. Controls pharmacy education standards and maintains the register of pharmacists.
• AICTE — approves technical/pharmacy institutions at the national level.
• IPA (Indian Pharmaceutical Association) — professional association of pharmacists.
• IDMA (Indian Drug Manufacturers' Association) and OPPI (Organisation of Pharmaceutical Producers of India) — industry bodies.

Exam angle: "Trace the history of pharmacy education in India" or "Write a note on the development of the pharmaceutical industry in India." Write it as a timeline — examiners love chronological answers here. Dates above are the standard textbook version; if your teacher's notes differ slightly, follow your teacher.

Scope of the Pharmacy Profession

A registered pharmacist is not just someone who hands over medicines. The syllabus divides the scope into three areas. Learn the role and responsibilities under each — questions almost always ask "role of pharmacist in…".

1. Retail / Community pharmacy This is the pharmacy you see on every street. The community pharmacist: - Dispenses medicines against prescriptions and counsels patients on dose, timing and storage. - Sells OTC products and gives basic health advice (first aid, minor ailments). - Checks prescriptions for errors — wrong dose, drug interactions, illegible writing — and contacts the prescriber when something looks off. - Maintains legally required records (narcotic registers, prescription files). - In India, this is also where generic substitution and patient education on completing antibiotic courses matter most.

2. Hospital and clinical pharmacy The hospital pharmacist works inside the healthcare team: - Manages the hospital drug store: procurement, storage (cold chain for vaccines/insulin), and distribution to wards. - Prepares sterile products (IV admixtures) and handles cytotoxic drugs where applicable. - Does clinical pharmacy work: attending ward rounds, monitoring drug therapy, reporting adverse drug reactions (ADRs) under the PvPI programme, and advising doctors on drug interactions and dose adjustments. - Patient counselling at discharge — especially for chronic diseases like diabetes and hypertension.

3. Industrial pharmacy (including R&D) - Production: manufacturing tablets, capsules, injectables under GMP. - Quality control / Quality assurance: testing raw materials and finished products against pharmacopoeial standards. - R&D: formulation development (making a stable, effective dosage form), analytical method development, and clinical trial support. - Regulatory affairs: preparing dossiers for drug approval (CDSCO in India, USFDA/EMA for exports). - Marketing and medical sales: product promotion to doctors (medical representatives).

Exam angle: "Describe the role and responsibilities of a pharmacist in hospital pharmacy" (or community, or industry). Pick the heading, write 6–8 crisp points. Never mix the three — keep them separate.

Pharmacopoeias

A pharmacopoeia is an official book that lays down standards for the identity, purity, strength and quality of drugs. If a drug is included in a pharmacopoeia, it must meet that book's standards — that is what makes them legally enforceable.

The main pharmacopoeias:

• IP — Indian Pharmacopoeia. Published by the Indian Pharmacopoeia Commission (IPC), Ghaziabad. First edition 1955; the 9th edition (IP 2022) is the latest widely used edition. It is the legal standard for drugs in India under the Drugs and Cosmetics Act.
• BP — British Pharmacopoeia. Published in the UK (by the MHRA). Used across Commonwealth countries.
• USP — United States Pharmacopeia (USP–NF). Published by the US Pharmacopeial Convention. The legal standard in the USA.
• BPC — British Pharmaceutical Codex. Flag: the BPC is largely historical — its last edition was in 1973 and its content was absorbed into the British National Formulary (BNF). Your syllabus still names it, so know what it was, but don't treat it as a current book.
• International Pharmacopoeia (Ph. Int.). Published by the WHO; meant for global use, especially where no national pharmacopoeia exists.
• National Formulary of India (NFI). Also published by IPC. While the IP sets standards, the formulary gives practical prescribing information — formulations, doses, and guidance for prescribers.

Structure and content of the Indian Pharmacopoeia: The IP is published in multiple volumes and contains: - Monographs — the core of the book. Each monograph covers one drug substance or formulation. - General notices — rules for interpreting the whole book. - General chapters — test methods (e.g., limit tests, dissolution, sterility testing). - Appendices — reference standards, reagents, and procedures. - It also covers vaccines, sera, biotechnology products and herbal drugs in recent editions.

Study of one model IP monograph (example: Paracetamol): A monograph follows a fixed pattern. Learn this skeleton — you can reproduce it for any drug:

1. Title — official name (e.g., Paracetamol).
2. Chemical name and structural formula.
3. Description — what it looks like (white crystalline powder).
4. Identification — tests proving it is what it claims to be (IR spectrum, chemical tests).
5. Tests — purity checks: related substances, heavy metals, loss on drying, sulphated ash.
6. Assay — the quantitative test for strength (e.g., "contains not less than 98.0% and not more than 101.0%").
7. Storage — how to store it (well-closed container, protected from light).
8. Labelling — what the label must state.
9. Category / Dose — therapeutic category and usual dose.

Exam angle: "Write a note on the Indian Pharmacopoeia" and "Describe the salient features of an IP monograph with an example." Draw the monograph skeleton as numbered points — it reads like you have actually opened the book.

Introduction to Prescription

A prescription is a written order from a registered medical practitioner to a pharmacist to supply and compound medicines for a patient. It is both a clinical document and a legal one.

Parts / structure of a prescription:

1. Date — every prescription must be dated.
2. Patient information — name, age, sex, address (and weight for children).
3. Superscription — the symbol Rx (from Latin recipe, "take thou").
4. Inscription — the names and quantities of the medicaments ordered.
5. Subscription — directions to the pharmacist (e.g., "mix and make 10 powders").
6. Signatura (transcription) — directions to the patient: dose, frequency, route ("take one tablet twice daily after food").
7. Prescriber's signature, name and registration number — without this, the prescription is not valid.

Handling of prescriptions (the correct order): 1. Receiving — accept it politely, check the date and prescriber details. 2. Reading and checking — read carefully; verify doses, check for interactions, incompatibilities and obvious errors. 3. Compounding/dispensing — prepare or pick the medicines accurately. 4. Labelling — label must carry patient name, directions, date, and pharmacy details. 5. Pricing and recording — enter in the prescription register. 6. Delivering and counselling — hand over with clear verbal instructions.

If anything is doubtful — an unusually high dose, an illegible drug name, a dangerous interaction — do not guess. Contact the prescriber. This one line earns marks in every prescription-handling answer.

Latin terminology used in prescriptions (learn these — they come as "expand the following"):

Unit I — Frequently asked questions

Q: What is a pharmacopoeia, and why does it matter in pharmacy? A: A pharmacopoeia is an official book of drug standards — it defines the identity, purity and strength every listed drug must meet. It matters because it is legally enforceable: a drug sold in India must comply with the Indian Pharmacopoeia, which protects patients from substandard medicines.

Q: What is the difference between the Indian Pharmacopoeia and the National Formulary of India? A: The IP sets quality standards (what the drug must be); the NFI gives prescribing guidance (how the drug is used — doses, formulations, clinical notes). Both are published by the IPC, Ghaziabad.

Q: What are the parts of a prescription? A: Date, patient information, superscription (Rx), inscription (medicines ordered), subscription (directions to the pharmacist), signatura (directions to the patient), and the prescriber's signature with registration number.

Q: Why is Latin still used in prescriptions? A: Latin abbreviations are short, precise and internationally understood, which reduces ambiguity in dosing instructions. That's also why you must learn their exact expansions — a wrong expansion in an exam or on a label is a serious error.

Unit I — Key takeaways

• Modern pharmacy education in India began with B.Pharm at BHU in 1937; the Pharmacy Act and PCI came in 1948; the first IP in 1955.
• Pharmacists work in community, hospital/clinical, and industrial pharmacy — learn the responsibilities under each head separately.
• IP (India), BP (UK), USP (USA), International Pharmacopoeia (WHO) are the key pharmacopoeias; BPC is historical.
• An IP monograph runs: title → chemical name → description → identification → tests → assay → storage → labelling → category/dose.
• A prescription has seven parts (date to signature); handle it in order and never guess at an illegible or doubtful order — contact the prescriber.

Unit II — Introduction to Pharmaceutical Calculations and Dosage Forms

This unit is the maths of pharmacy. It looks intimidating, but every calculation here follows a fixed formula — learn the formula, plug in numbers, and the marks are yours. Alongside the maths, you learn the basic language of dosage forms: routes of administration, what an API is, and what excipients do.

Metric system of weights and measures

Pharmacy uses the metric system almost exclusively: grams (g) for weight, litres (L) for volume, metres for length. You must be fluent in conversions:

• 1 kg = 1000 g; 1 g = 1000 mg; 1 mg = 1000 micrograms (mcg or µg)
• 1 L = 1000 mL
• Household measures you will still see: 1 teaspoon ≈ 5 mL, 1 tablespoon ≈ 15 mL, 1 drop ≈ 0.05 mL (20 drops ≈ 1 mL)

Scientific notation is used for very large or small quantities: 0.00025 g = 2.5 × 10⁻⁴ g. In exams, always convert everything to the same unit before calculating.

Alligation

Alligation is a method for mixing two preparations of different strengths to obtain a preparation of an intermediate strength. It answers questions like: "How much of 70% alcohol and 30% alcohol do I mix to get 50% alcohol?"

Alligation alternate (the cross method):

Higher strength (H) ──────┐
                          ├──> (D − L) parts of higher strength
Desired strength (D) ─────┤
                          ├──> (H − D) parts of lower strength
Lower strength (L) ───────┘

• Parts of higher-strength ingredient = D − L
• Parts of lower-strength ingredient = H − D
• Total parts = H − L

Worked example: Prepare 500 mL of 40% alcohol from 70% and 20% alcohol. - Parts of 70% = 40 − 20 = 20 parts - Parts of 20% = 70 − 40 = 30 parts - Total = 50 parts → 500 mL ÷ 50 = 10 mL per part - 70% alcohol needed = 20 × 10 = 200 mL; 20% alcohol needed = 30 × 10 = 300 mL.

Exam angle: Alligation numericals are almost guaranteed. Write the cross diagram — it shows method marks even if the arithmetic slips.

Proof spirit

Proof spirit is a reference standard for alcohol strength: it contains 57.1% v/v ethanol (at 15.56 °C / 60 °F). Alcohol strengths are expressed relative to it:

• 100° proof = 57.1% v/v ethanol (this is proof spirit itself)
• Over proof (O.P.): stronger than proof spirit. E.g., 25° O.P. = 125° proof.
• Under proof (U.P.): weaker than proof spirit. E.g., 25° U.P. = 75° proof.

Conversion: % v/v ethanol = (proof strength ÷ 100) × 57.1. So a spirit labelled 70° proof contains (70/100) × 57.1 = 39.97% ≈ 40% v/v ethanol.

Isotonic solutions

A solution is isotonic with body fluids (tears, blood plasma) when it exerts the same osmotic pressure — roughly equivalent to 0.9% w/v sodium chloride. Eye drops and injections must be isotonic, otherwise they cause pain, irritation or haemolysis.

Two standard methods to adjust tonicity:

1. Sodium chloride equivalent (E value) method: E = the amount of NaCl that produces the same osmotic effect as 1 g of the drug. Calculate NaCl needed = 0.9 − (E × drug quantity per 100 mL), then add that much NaCl.
2. Freezing point depression method: blood plasma freezes at −0.52 °C. Adjust the solution so its freezing point is also −0.52 °C.

Exam angle: "Define isotonic solution. Describe the methods of adjusting tonicity." One definition + two methods with one line of principle each = full marks.

Dilute solutions — percentage and ratio

• % w/w = grams of solute per 100 g of solution (used for ointments, e.g., 5% w/w).
• % w/v = grams of solute per 100 mL of solution (most liquids, e.g., 0.9% w/v NaCl).
• % v/v = mL of solute per 100 mL of solution (e.g., alcohol).
• Ratio strength = 1:1000 means 1 g in 1000 mL. So 1:1000 = 0.1% w/v. To convert: % = (1 ÷ ratio) × 100.

Geometric dilution

When mixing a very small quantity of a potent drug uniformly into a large quantity of powder, you don't dump it in at once. Geometric dilution means mixing the drug with an approximately equal volume of diluent, then doubling the diluent each time until all is incorporated. This is how potent powders (e.g., a few mg of drug in grams of lactose) are blended uniformly. Mortar and pestle, trituration — and the same principle is used when incorporating potent drugs into ointment bases.

Posology

Posology (from Greek posos = how much, logos = study) is the study of doses — the science of determining the correct dose of a drug for a patient.

Dose calculation formulas (adult dose is the reference; learn what each uses):

Worked example (Young's): Adult dose 500 mg, child aged 6 years → 6/(6+12) × 500 = (6/18) × 500 = 166.7 mg.

BSA is considered the most accurate for children because it correlates best with metabolic rate; it is calculated by the Mosteller formula: BSA (m²) = √[height(cm) × weight(kg) ÷ 3600].

Exam angle: "Define posology. Calculate the dose for a 4-year-old child if the adult dose is 250 mg" — state the formula by name, then solve. Naming the formula matters.

Introduction to dosage forms — routes of administration and classification

A dosage form is the physical form in which a drug is presented for administration (tablet, syrup, injection…). The route of administration decides how fast the drug acts and where it goes:

• Oral — tablets, capsules, syrups. Convenient, but slow onset and first-pass metabolism.
• Sublingual / buccal — under the tongue / cheek (e.g., nitroglycerin, sorbitrate). Fast, avoids first-pass.
• Parenteral — IV (fastest), IM, SC, intradermal, intrathecal. Sterile, used when oral isn't possible.
• Rectal — suppositories, enemas. Useful in vomiting/unconscious patients and children.
• Topical — ointments, creams, lotions on skin.
• Inhalation — aerosols, nebulisers for asthma (direct to lungs).
• Nasal, ophthalmic, otic — nose drops, eye drops, ear drops.
• Transdermal — patches delivering drug through skin over hours.

Classification of dosage forms (classify any way the question asks — by physical state is the commonest):

• Solid: tablets, capsules, powders, granules, pills, lozenges.
• Liquid: monophasic (syrups, elixirs) and biphasic (suspensions, emulsions).
• Semisolid: ointments, creams, gels, pastes.
• Gaseous: aerosols, inhalations.
• Also classified by route (oral, parenteral, topical…) or by release (immediate, sustained, controlled).

Active Pharmaceutical Ingredients and Excipients

• API (Active Pharmaceutical Ingredient): the substance in the formulation that produces the therapeutic effect (e.g., paracetamol in a Crocin tablet).
• Excipient: any substance other than the API included in the formulation to help manufacture it, keep it stable, or make it acceptable to the patient (e.g., starch as binder/disintegrant, lactose as diluent, colourants, flavourants).

Ideal characteristics of excipients: inert (no reaction with the drug), non-toxic, stable, compatible with the API and packaging, and economical. Their importance: without excipients you cannot make a tablet that holds together, a syrup that pours and tastes acceptable, or a suspension that stays uniform. Excipients decide whether a good drug becomes a usable medicine.

Exam angle: "Define API and excipient. What are the ideal characteristics of excipients?" — a favourite 5-mark short note.

Unit II — Frequently asked questions

Q: What is posology? A: Posology is the branch of pharmacy dealing with the determination of drug doses — how much of a drug to give based on factors like the patient's age, weight and body surface area.

Q: What is the difference between Young's formula and Clark's formula? A: Young's formula calculates a child's dose from age (age ÷ (age + 12) × adult dose); Clark's formula calculates it from body weight (weight ÷ 150 lb, or ÷ 70 kg, × adult dose). BSA-based dosing is the most accurate of all.

Q: What is proof spirit? A: Proof spirit is the reference standard for alcohol strength, containing 57.1% v/v ethanol. 100° proof equals proof spirit itself; strengths above it are "over proof" and below it "under proof".

Q: Why must eye drops be isotonic? A: Tears are isotonic with 0.9% sodium chloride. A hypertonic or hypotonic eye drop causes stinging, irritation and tissue damage, so tonicity is adjusted (usually by the NaCl equivalent method) before the product is released.

Unit II — Key takeaways

• Alligation mixes two strengths to get an intermediate one — draw the cross diagram: parts of higher = D − L, parts of lower = H − D.
• Proof spirit = 57.1% v/v ethanol = 100° proof.
• Isotonic = same osmotic pressure as body fluids (0.9% NaCl); adjust by NaCl equivalent or freezing-point method.
• Posology = the study of doses; Young's (age), Clark's (weight), Fried's (infants, months), BSA (most accurate).
• API gives the therapeutic effect; excipients make manufacture and use possible — ideal excipients are inert, non-toxic, stable and compatible.
• Geometric dilution blends tiny quantities of potent drug uniformly by doubling the diluent stepwise.

Unit III — Solid Dosage Forms

Solid dosage forms are the backbone of pharmacy — tablets and capsules make up the majority of medicines dispensed anywhere. This unit covers powders, tablets and capsules: what each type is for, their advantages and disadvantages, and how they are made. Draw comparisons in the exam; "advantages and disadvantages" questions are near-certain.

Powders

Powders are solid dosage forms containing one or more drugs in a dry, finely divided state. They are among the oldest dosage forms and are still used where tablets can't be — for very large doses, for external dusting, or for drugs unstable in liquid.

Classification (learn with one example each):

• Bulk powders — dispensed in bulk; the patient measures the dose (e.g., antacid powder).
• Divided powders — individually wrapped doses (e.g., ORS powder sachets).
• Dusting powders — applied externally to skin. Two types: medical (contain medicament, e.g., zinc oxide + starch antiseptic powder) and surgical (sterile, used on wounds). They must be very finely sifted so they don't irritate.
• Effervescent powders — contain sodium bicarbonate with citric/tartaric acid; on contact with water they release CO₂, giving a fizzy drink (e.g., ENO). The fizz masks taste and speeds absorption.
• Efflorescent powders — contain drugs that lose their water of crystallisation on exposure to air and become damp (e.g., substances like ferrous sulphate-type hydrates in textbook examples). They are dried gently before mixing and packed in well-closed containers.
• Hygroscopic powders — absorb moisture from air (and may cake). They need airtight packing; sometimes a desiccant sachet is included.
• Eutectic mixtures — two solids that liquefy when mixed because the mixture's melting point drops below room temperature (classic pair: menthol + camphor, or menthol + thymol). Handled by triturating each with an inert absorbent (light magnesium oxide or lactose) before mixing, or dispensing the components separately.

Advantages of powders: suitable for large doses that won't fit in a tablet; fast dissolution and absorption; easy to compound; useful externally. Disadvantages: bitter/unpleasant drugs taste bad; hygroscopic drugs cake; not convenient to carry; dose measurement by the patient can be inaccurate.

Excipients and preparation (introductory level): diluents like lactose and starch bulk up small drug quantities; preparation is by trituration (grinding in a mortar) or simple mixing, then sifting and packing.

Tablets

A tablet is a solid dosage form containing a drug (with or without excipients), prepared by compression (or moulding) into a flat or biconvex disc.

Types of tablets (with examples):

• Compressed tablets — the ordinary tablet (e.g., paracetamol/Crocin).
• Sugar-coated tablets — coating masks bitter taste and protects (e.g., older vitamin tablets).
• Film-coated tablets — thin polymer coat for taste-masking and stability.
• Enteric-coated tablets — coating resists stomach acid and dissolves in the intestine; used for drugs irritating to the stomach or destroyed by acid (e.g., omeprazole, diclofenac enteric tablets).
• Chewable tablets — chewed before swallowing, for children or antacids (e.g., Digene).
• Sublingual / buccal tablets — dissolve under the tongue or in the cheek for rapid action (e.g., sorbitrate/nitroglycerin).
• Effervescent tablets — dissolve in water with effervescence (e.g., vitamin C tablets).
• Dispersible tablets — disperse quickly in water before administration.
• Sustained-release / controlled-release tablets — release drug slowly over hours (e.g., metformin SR).
• Moulded tablets (tablet triturates) — flag: these are made by moulding moist powder, not compression; small, rapidly dissolving, historically used for potent drugs like nitroglycerin. Largely obsolete today but examiners still ask "what are moulded tablets".
• Pills — flag: small spherical masses made by rolling; the traditional dosage form that tablets replaced. Know the definition; you will rarely see real pills in modern practice.

Advantages: accurate dosing, convenient, stable, portable, taste-masking possible via coating, economical for mass production. Disadvantages: slow onset compared to liquids; difficult for children/elderly to swallow; drugs unstable to compression or with very large doses don't suit.

Excipients and preparation (introductory): diluents (lactose, starch), binders (starch paste, PVP), disintegrants (starch, croscarmellose), lubricants (magnesium stearate, talc), glidants. Manufacture is by wet granulation, dry granulation, or direct compression — granules are made first (except direct compression), then compressed on a tablet machine.

Capsules

A capsule is a solid dosage form in which the drug is enclosed in a gelatin shell.

Types:

• Hard gelatin capsules — two-piece (body + cap), filled with powders or granules (e.g., amoxicillin capsules, omeprazole). This is the common capsule you see.
• Soft gelatin capsules — one-piece sealed shell, filled with liquids or semi-solids (e.g., vitamin E Evion, cod liver oil).

Capsule sizes: hard capsules come in sizes 000, 00, 0, 1, 2, 3, 4, 5 — 000 is the largest, 5 the smallest; size 0 is the most commonly used. (Easy memory hook: more zeros = bigger capsule.)

Advantages: tasteless shell masks bitter drugs; elegant; fast disintegration; suitable for liquids (soft); accurate dosing. Disadvantages: not for very hygroscopic drugs (gelatin absorbs moisture); not for large doses; gelatin is animal-derived (a concern for some patients); more expensive than tablets.

Excipients and preparation (introductory): diluents (lactose), lubricants/glidants for filling; hard capsules are filled on capsule-filling machines (hand-operated to automatic), soft capsules by rotary-die process.

Unit III — Frequently asked questions

Q: What is the difference between effervescent and efflorescent powders? A: Effervescent powders release CO₂ on contact with water (sodium bicarbonate + organic acid, e.g., ENO) and are designed to fizz. Efflorescent powders contain drugs that lose water of crystallisation in air and become damp, so they must be pre-dried and packed airtight — the similarity in names is exactly why examiners pair them.

Q: What is a eutectic mixture? Give an example and how it is handled. A: A mixture of two solids (e.g., menthol + camphor) whose combined melting point falls below room temperature, so they liquefy on mixing. Handle by triturating each separately with an inert diluent like light magnesium oxide before combining, or dispense separately.

Q: What are moulded tablets? A: Tablets made by moulding moist powder mass (not compression), small and fast-dissolving, e.g., nitroglycerin tablets. They are largely obsolete but still asked as a definition.

Q: Which capsule size is the largest and which is most commonly used? A: Size 000 is the largest and 5 the smallest; size 0 is the most commonly used hard gelatin capsule size.

Unit III — Key takeaways

• Powders suit large doses and external use; watch out for eutectic (liquefy — menthol + camphor), effervescent (fizz — ENO) vs efflorescent (lose water, go damp).
• Tablets are made by compression (moulded tablets and pills are the historical exceptions).
• Enteric coating protects the stomach from the drug and the drug from stomach acid.
• Hard gelatin = two-piece for powders (sizes 000 largest → 5 smallest, 0 commonest); soft gelatin = one-piece for liquids/oils.
• Advantages/disadvantages of each dosage form are the highest-yield exam questions in this unit — learn them as paired lists.

Unit IV — Monophasic and Biphasic Liquids

Liquid dosage forms are either monophasic (one clear phase — true solutions) or biphasic (two phases — suspensions and emulsions). This is the longest unit in BP102T. Learn each preparation as: definition → example → key point about preparation. The examples are what make answers look like they come from a pharmacy student, not a textbook index.

Monophasic liquids for internal use

Aromatic waters — clear, aqueous solutions of volatile oils or aromatic substances, used as flavouring vehicles (e.g., chloroform water, peppermint water, rose water, camphor water). Prepared by shaking the aromatic substance with purified water and filtering. They must be stored in well-closed containers, protected from light — volatile constituents escape and degrade otherwise.

Syrups — concentrated aqueous solutions of sucrose (or other sugars). Simple syrup IP contains 66.7% w/w sucrose, which itself acts as a preservative (high osmotic pressure stops microbial growth). Used as sweet vehicles for bitter drugs (e.g., cough syrups). Prepared by dissolving sucrose in purified water with heat, or by agitation without heat for heat-sensitive additions.

Elixirs — clear, sweetened hydroalcoholic liquids (contain alcohol, typically 5–40%) used as vehicles for drugs (e.g., phenobarbitone elixir). The alcohol keeps both water-soluble and alcohol-soluble ingredients in solution and acts as a preservative. Not for children or alcohol-restricted patients in large volumes — a point worth mentioning in answers.

Linctus — viscous, sweet liquid preparations taken in small doses for the soothing action on the throat in cough (e.g., codeine linctus, pholcodine linctus). They are sipped slowly and not diluted with water, so the drug stays in contact with the throat mucosa.

Monophasic liquids for external use and body cavities

• Liniments — liquid/semi-liquid preparations rubbed onto the skin with friction; may be alcoholic or oily (e.g., turpentine liniment). Labelled "for external use only" and "shake well".
• Lotions — aqueous preparations dabbed (not rubbed) onto skin without friction, for soothing/cooling effect (e.g., calamine lotion).
• Throat paints — viscous liquids applied to the throat with a brush (e.g., traditional iodine-based throat paints).
• Applications — an older term for liquids/semi-liquids applied to skin (the syllabus lists it; know it as a historical category).
• Gargles — aqueous solutions used to treat the throat by gargling and spitting out (e.g., phenol/potassium chlorate-type gargles in textbooks; Betadine gargle is the modern familiar example).
• Mouthwashes — used to cleanse/deodorise the mouth (e.g., chlorhexidine mouthwash).
• Enemas — liquids administered rectally for evacuation or retention of medicament.
• Eye drops — sterile aqueous/ oily solutions instilled into the eye; must be sterile, isotonic and buffered (ties back to Unit II).
• Ear drops — instilled into the ear (e.g., wax-softening drops).
• Nasal drops — instilled into the nose (e.g., decongestant drops).
• Tinctures — alcoholic (or hydroalcoholic) extracts of crude drugs (e.g., tincture of iodine, compound tincture of benzoin). Prepared by maceration or percolation.

Memory hook for the exam: internal = waters, syrups, elixirs, linctus (4). Everything else in the list is external or body-cavity. If a question says "classify monophasic liquids", that split is your answer's skeleton.

Official preparations, excipients and methods (introductory): official = listed in the pharmacopoeia. Excipients here include vehicles (purified water, alcohol, glycerin), sweeteners (sucrose, sorbitol), preservatives (benzoates, parabens), flavours and colours. General methods: solution (dissolve with stirring/heat), maceration and percolation (for tinctures/extracts), filtration and clarification.

Suspensions — biphasic liquids

A suspension is a biphasic liquid dosage form in which finely divided solid particles are dispersed in a liquid vehicle (usually water). Shake well before use — that instruction exists because the drug settles.

Types:

• Flocculated suspensions — particles form loose aggregates (flocs). They settle rapidly but the sediment is fluffy and easily redispersed by shaking. No caking. This is the preferred type.
• Deflocculated suspensions — particles remain as individual fine particles. They settle slowly, but the sediment packs into a hard cake that is difficult to redisperse. This is the problem formulators avoid.

Advantages: suitable for drugs that are insoluble or unstable in solution; masks bitter taste better than solutions; higher drug loading possible; prolonged action possible. Disadvantages: physical instability (settling, caking); dose uniformity depends on shaking; bulky.

Formulation excipients: suspending/viscosity agents (tragacanth, bentonite, sodium CMC, methylcellulose) to slow settling; wetting agents (surfactants) so hydrophobic particles disperse; flocculating agents (electrolytes) to create flocs; sweeteners, flavours, preservatives.

General method of preparation: triturate the drug with the wetting agent, add the suspending agent (often as a mucilage), incorporate gradually with the vehicle, make up to volume, and pack with a "shake well before use" label.

Emulsions — biphasic liquids

An emulsion is a biphasic liquid in which one liquid is dispersed as fine droplets in another immiscible liquid, stabilised by an emulsifying agent.

Types:

• Oil-in-water (o/w) — oil droplets in water (e.g., vanishing-cream type bases; oral emulsions like cod-liver-oil emulsion). Washable, preferred for internal use.
• Water-in-oil (w/o) — water droplets in oil (e.g., cold cream type). Greasy, used externally.

Emulsifying agents: natural (acacia, tragacanth, gelatin, egg yolk), synthetic non-ionic surfactants (Tweens — hydrophilic, favour o/w; Spans — lipophilic, favour w/o), and finely divided solids (bentonite).

Tests for identification of emulsion type (learn all four — classic exam question):

1. Dilution test — an o/w emulsion dilutes freely with water; a w/o emulsion does not (it dilutes with oil).
2. Dye test — a water-soluble dye colours the continuous phase: uniform colour = o/w; spotted colour = w/o (and vice versa with an oil-soluble dye).
3. Conductivity test — o/w conducts electricity (water is the continuous phase); w/o does not.
4. Fluorescence test — under UV light, o/w shows spotty fluorescence, w/o shows uniform fluorescence (oils fluoresce).

Formulation excipients: emulsifying agents (above), preservatives, antioxidants, flavours/sweeteners for oral emulsions. General methods of preparation: dry gum (continental) method — acacia + oil triturated first, then water added at once to form the primary emulsion; wet gum (English) method — acacia + water mucilage first, then oil added gradually; bottle method — for volatile oils, shaken in a bottle.

Unit IV — Frequently asked questions

Q: What is the difference between a syrup and an elixir? A: A syrup is an aqueous, sugar-based vehicle (66.7% w/w sucrose in simple syrup IP); an elixir is a sweetened hydroalcoholic vehicle containing alcohol. Elixirs dissolve drugs that won't dissolve in water alone, but the alcohol content limits their use in children.

Q: What is the difference between a lotion and a liniment? A: A liniment is rubbed onto the skin with friction (alcoholic or oily); a lotion is dabbed on without friction (aqueous, cooling/soothing). Calamine lotion vs turpentine liniment is the standard example pair.

Q: What is the difference between flocculated and deflocculated suspensions? A: Flocculated suspensions settle fast as loose flocs that redisperse easily — no caking. Deflocculated suspensions settle slowly as individual particles that pack into a hard, difficult-to-redisperse cake. Flocculated is preferred.

Q: How do you identify whether an emulsion is o/w or w/o? A: By the dilution test (o/w dilutes with water), dye test (water-soluble dye colours o/w uniformly), conductivity test (o/w conducts electricity), and fluorescence test under UV light.

Q: What is the difference between a gargle and a mouthwash? A: A gargle treats the throat (gargled and spat out); a mouthwash cleanses/deodorises the mouth. Different site of action, different formulation.

Unit IV — Key takeaways

• Monophasic = one phase (true solutions); internal four are aromatic waters, syrups, elixirs, linctus — the rest are external/body-cavity.
• Simple syrup IP = 66.7% w/w sucrose; linctus is sipped undiluted for throat contact.
• Liniment = rubbed; lotion = dabbed; gargle = throat; mouthwash = mouth.
• Suspensions: flocculated (fast settling, easy redispersion — good) vs deflocculated (slow settling, caking — bad).
• Emulsions: o/w vs w/o; emulsifiers include acacia, Tweens (o/w) and Spans (w/o); identify type by dilution, dye, conductivity, fluorescence tests.
• Preparation methods: dry gum (continental) vs wet gum (English) vs bottle method.

Unit V — Semisolid Dosage Forms

Semisolids sit between solids and liquids — they stay where you put them on skin or mucosa but spread under pressure. This unit covers ointments, pastes, creams and gels, then suppositories/pessaries. The highest-yield topics here: ointment bases (four types) and displacement value.

Definitions and classification

Semisolid dosage forms are preparations of such consistency that they adhere to the skin or mucous membrane when applied, without being fluid enough to flow.

Classification:

• Ointments — greasy semisolids for external application carrying medicament in a base (e.g., sulphur ointment).
• Pastes — stiffer than ointments; contain a high proportion of insoluble powder (20–50%), so they are less greasy, more protective and stay in place (e.g., zinc oxide paste).
• Creams — semisolid emulsions, either o/w (vanishing creams — washable, non-greasy) or w/o (cold creams — greasy, emollient).
• Gels (jellies) — transparent/translucent semisolids where the liquid is thickened by a gelling agent (e.g., carbopol-based diclofenac gel/Volini-type gels).

Advantages: direct local action at the site; avoid first-pass metabolism; easy to apply; good for skin diseases. Disadvantages: greasy and messy (ointments); inaccurate dosing; poor patient acceptability for weeping wounds; stability issues (rancidity of fatty bases).

Ointment bases and other excipients

The base decides how the ointment behaves — drug release, greasiness, washability. There are four types; learn them as a table:

Other excipients: preservatives (parabens), antioxidants (for fatty bases), humectants (glycerin), stiffening agents (waxes), and of course the medicament itself.

General methods of preparation:

1. Trituration method — for insoluble powders: finely powder the drug, triturate with a small portion of base on an ointment slab, then geometrically dilute with the rest of the base.
2. Fusion method — for waxy bases: melt the base ingredients in decreasing order of melting point, add the drug (dissolved or suspended), stir while cooling to avoid grittiness.

Exam angle: "Classify ointment bases with examples" — reproduce the four-row table. It is one of the most repeated questions in this subject.

Suppositories and pessaries

A suppository is a solid dosage form for rectal administration that melts, softens or dissolves at body temperature to release the drug. Pessaries are the vaginal equivalent (larger, often ovoid); urethral suppositories are called bougies.

Types: rectal (torpedo/cone-shaped, ~1–2 g), vaginal/pessaries (larger, ovoid), urethral bougies (thin, pencil-shaped).

Advantages: useful when the patient is vomiting or unconscious; for children who can't swallow; avoids first-pass metabolism partially (lower rectum drains into systemic circulation); local action for piles/constipation (e.g., glycerin suppositories). Disadvantages: patient acceptability is low; incomplete/irregular absorption; storage problems in hot climates (they melt).

Properties of an ideal suppository base:

• Melts at body temperature (or dissolves in body fluids) and releases the drug promptly.
• Non-toxic, non-irritant, stable, and compatible with the drug.
• Contracts slightly on cooling so the suppository releases easily from the mould.
• Has good emulsifying/water-absorbing capacity where needed.

Types of suppository bases:

• Oleaginous bases — cocoa butter (theobroma oil): the classic base, melts at body temperature (~34–35 °C), but goes rancid and has polymorphism problems in hot climates.
• Water-soluble / water-miscible bases — glycero-gelatin (for vaginal use, dissolves slowly) and macrogols/PEG bases (stable in heat, no rancidity, but hygroscopic).

Displacement value — because the drug occupies space in the mould, a fixed weight of drug displaces a certain weight of base. The displacement value of a drug is the quantity of drug that displaces one part (1 g) of the base. It is needed to calculate how much base to use so that each suppository still contains the correct drug dose:

Base required = (mould capacity × number of suppositories) − (drug quantity ÷ displacement value)

Exam angle: "Define displacement value" is a 2-mark favourite; a numerical on it is a 5-mark favourite. Memorise the definition word-for-word and the formula above.

General method of preparation: fusion/moulding — melt the base, incorporate the drug (dissolved or suspended with stirring), pour into cooled, lubricated moulds, allow to set, trim and pack. (Cold compression/hand-rolling is the older alternative.)

Unit V — Frequently asked questions

Q: What is the difference between an ointment, a cream and a paste? A: An ointment is a greasy medicated semisolid in a base; a cream is a semisolid emulsion (o/w vanishing or w/o cold cream); a paste contains a high proportion of insoluble powder (20–50%), making it stiffer, less greasy and more protective than an ointment.

Q: What are the four types of ointment bases? Give one example of each. A: Oleaginous (white soft paraffin), absorption (wool fat/lanolin), emulsion/water-removable (hydrous wool fat), and water-soluble (macrogol/PEG ointment).

Q: What is displacement value in suppositories? A: The quantity of drug that displaces one gram of suppository base in the mould. It is used to calculate the exact amount of base needed so each suppository contains the correct dose.

Q: Why are suppositories used? A: For patients who can't take oral medicines (vomiting, unconsciousness, children), for local rectal action (piles, constipation), and to partly bypass first-pass metabolism.

Unit V — Key takeaways

• Semisolids: ointments (greasy), pastes (stiff, high powder content), creams (emulsions — o/w vanishing, w/o cold), gels (transparent, gelling agent).
• Four ointment bases: oleaginous, absorption, emulsion, water-soluble — one example each is exam gold.
• Preparation by trituration (powders) or fusion (waxy bases, melt in decreasing melting-point order).
• Suppository = rectal, pessary = vaginal, bougie = urethral; ideal base melts at body temperature, is non-irritant and releases from the mould.
• Displacement value = drug quantity displacing 1 g of base — definition + formula both matter.
• Classic bases: cocoa butter/theobroma oil (oleaginous, melts at body temp) vs glycero-gelatin and macrogols (water-soluble).

End of BP102T General Pharmacy notes — Units I to V. Syllabus source: B.Pharm (NEP 2020, 2026) Semester I structure; topics follow the official unit plan. Two flags for students: (1) the BPC is a historical book — know it for exams, don't cite it as current; (2) confirm the latest IP edition with your teacher, as new editions release periodically.

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