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COLLEGE OF
PHARMACY
Dr. Mohammad Javed Ansari, PhD.
Contact info: [email protected]
PHARMACEUTICS-I
(PHT 224)
INTRODUCTION : Pharmaceutics &
DOSAGE FORMS design
OBJECTIVES OF THE LECTURE
• At the end of this lecture, you will be able to explain:
• What is pharmaceutics?
• What are drugs?
• What are excipients?
• What are dosage forms?
• Why drugs are not used as such?
• Why formulation of dosage form is necessary?
• What are various dosage forms?
• What are various factors that affect design of dosage forms?.
PHARMACY & PHARMACEUTICS
• Pharmacy is the study of all aspects of drugs, both natural and
synthetic in origin, including-
• their chemistry,
• their uses in medicines,
• and how they work within the body.
• Pharmaceutics is the study of all aspects of turning an active
pharmaceutical agent (API) into a Stable, Safe & Effective
(SSE) dosage form. It includes-
• Physicochemical factors (Pre-formulation studies),
• Biopharmaceutical factors (Formulation studies),
• Therapeutical factors (Patient age & disease)
• Suitable dosage forms (SSE) must be developed with
optimum dosing regimen (OD, BD and IM) that overcome
barriers and optimize drug action (minimize adverse effects).
• Pharmacy is the science of drugs and Pharmaceutics is the
science of drug delivery (dosage form design).
PHARMACODYNAMICS
Site/mechanism of action, potency, efficacy, etc.
PHARMACOKINETICS
absorption, distribution, metabolism, excretion
Stable
Elegant
Stable
Safe
Effective
↑↑↑ Benefits
↓↓↓ Harm
PHARMACY & PHARMACEUTICS
PHARMACY & PHARMACEUTICS
• Pharmaceutics also deals with quantitative characterization of
• drug concentration-effect relationship (Pharmacodynamics) and
• drug concentration-time profile (Pharmacokinetics) after it enters the body.
• Pharmaceutics is unique to pharmacy
• Physicians and other prescribers don’t learn and apply physical
pharmaceutical principles
• Chemists and engineers don’t learn a whole lot of biology
• Pharmacist consider all relevant factors to develop stable and
elegant dosage form so as to deliver a drug safely and
effectively to get maximum benefit and minimum harm.
DRUG VERSUS DOSAGE FORMS: RATIONALE OF DESIGN
• Drug ?
• Active drug substance (active pharmaceutical ingredient - API)
• chemical compound with pharmacological (or other direct effect ) intended for used in diagnosis, treatment or prevention of diseases
• International non-proprietary names (INN / “generic“ names)
• Direct clinical use of the active drug substances is rare: Why??
• Rational behind drug formulation or dosage form design
• API handling and Accurate dosing can be difficult or impossible (e.g., potent drugs: low mg and g doses)
• API administration can be impractical/unfeasible because of size, shape, smell/odour, taste and low activity.
• Some API are chemically unstable in light, moisture, O2
• API can be degraded at the site of administration (e.g., low pH in stomach).
• API may cause local irritations or injury when they are present at high concentrations at the site of administration.
• Administration of active substance would mean to have no chance for modification (improvement) of its PK profile
• To provide for the safe and convenient delivery of
accurate dosage of potent drugs like Digoxin (0.25
mg) Thyroxin (0.05 mg) we can design tablets,
capsules, syrups, injections etc.
• For the protection of a drug substance from the
destructive influence of atmospheric oxygen or
moisture, we can design coated tablets, sealed
ampules.
• For the protection of a drug substance from the
destructive influence of gastric acid after oral
administration we can design enteric coated tablets.
• To conceal the bitter taste, salty obnoxious or odor
of a drug substance we can design capsules, coated
tablets, flavored syrups
Need of drug formulations : overcoming the difficulties
• To provide liquid dosage forms of soluble drugs for
infants & children we can design solutions, syrups.
• To provide liquid preparations of drugs that are either
insoluble or unstable we can design suspension.
• To provide liquid preparations of oily drugs we can
design emulsions.
• To provide faster local effects with less side effects we
can design, inhalational aerosols, eye drops, ear drops,
ointments, enemas, rectal and vaginal suppositories.
• To provide very long duration of action for chronic
diseases we can design Implants.
• To deliver drugs with undesirable pharmacokinetic
profiles we can develop modified release or controlled
release formulations.
Need of drug formulations : overcoming the difficulties
Definition: Dosage forms are the means by which drug molecules / APIs are delivered to sites of action within the body to produce optimum desired effects and minimum adverse effect.
The need for dosage forms: DRUG SAFETY/BENEFIT:
Protection from environment (light, moisture, O2).
Protection from patients (gastric juice).
PATIENTS SAFETY/BENEFIT:
Accurate dose of potent drugs for children and elderly patients
Preventing local drug irritations/ ulcers.
Modifying PK of drug for optimum action(↑ benefits,↓ side effects)
Masking taste and odour of API.
Presenting API in desired / required forms. (Use of desired vehicle for insoluble drugs, insertion of drugs into body cavities and placement of drugs within body tissues like implants).
Need of drug formulations : overcoming the difficulties
They are classified according to:
Route of administration Physical form
Oral Solid
Topical Semisolid
Transdermal Liquid
Parenteral Gases
Inhalation
Buccal & sublingual
Ophthalmic
Otic
Rectal
Vaginal
TYPES OF DOSAGE FORMS
TYPES OF DOSAGE FORMS: Physical
Semi-solid dosage forms
Shaped
Suppositories (for rectal administration)
Pessaries (vaginal suppositories)
Unshaped Gels, Creams, Ointments, Pastes
Solid dosage forms
Shaped Tablets, Capsules, Implants, Transdermal patches
Unshaped powders for external/internal use
Liquid dosage forms
Monophasic Solutions (syrups, spirits, elixirs, Tinctures)
Biphasic Emulsions, Suspension
External solutions: Lotions, Liniments, Collodions etc
Gaseous dosage forms
Medicinal gases Aerosols: Inhalation/volatile anaesthetics
Aerodispersions Antiasthmatics sprays
TYPES OF DOSAGE FORMS: Route of Administration
Enteral
Oral Tablets, Capsules, syrups, suspension, emulsion etc. Dry Powder Inhaler (DPI) pressurized Metered Dose Inhaler
(pMDI) • Nebulizer • Vaporizer
Sub-lingual
Buccal Orally Disintegrating Tablet (ODT) • Lozenges • Chewing
tablets, Mouthwash • Toothpaste • Ointment • Oral spray
Rectal Ointment • Suppository • Enema • Nutrient enema
Topical
Dermal Ointment • Liniment • Paste • Cream • Lotion • Lip balm •
Medicated shampoo • Dermal patch •
Mucosal Ear drops • Eye drops • Nasal spray • Ointment • Hydrogel •
Nanosphere suspension • Mucoadhesive microdisc
(microsphere tablet), pessaries.
Percutaneous: Transdermal patch etc
Parenteral (injections & infusions)
Intravenous • Intramuscular • Intracardiac • Intraosseous •
Intraperitoneal • Intracerebral • Intrathecal • Intradermal • Subcutaneous
• Active drug substance (active pharmaceutical ingredient - API)
• Excipients (inactive pharmaceutical ingredients)
• Diluents/fillers, binders, lubricants, disintegrants, coatings, preservantives and stabilizers, colorants and flavourings.
• Technological, biopharmaceutical and/or stability reasons
• Pharmaceutical dosage form
• is a drug delivery system which is formed by technological processing (drug formulation)
• determines the physical form of the final pharmaceutical preparation
• Pharmaceutical preparation (PP)
• particular pharmaceutical product containing active and inactive pharmaceutical ingredients formulated into the particular dosage form.
• Packed and labelled appropriately
• Two major types of PP according the origin:
• Manufactured in large scales by pharmaceutical industry (original and generic preparations)
• Compounded individually in compounding pharmacies
From drug substance to Pharmaceutical Dosage forms
• Drug substances /API are seldom administered in their
natural or pure state, but rather as part of a formulation in
combination with one or more excipients such as
diluents/fillers, binders, lubricants, disintegrants, coatings,
preservantives / stabilizers, solublizers, colors and flavors.
• It is the pharmaceutical excipients that serves to
solubilize, suspend, thicken, dilute, emulsify, stabilize,
preserve, provide color, flavor and fashion the drug
substances (API) into safe, stable, effective and appealing
pharmaceutical preparations.
• Therefore these excipients are also called as
pharmaceutical aids / pharmaceutical ingredients /,
pharmaceutical adjuncts / pharmaceutical necessities.
• Through selective use of these excipients we can design
and develop various type of dosage forms or
pharmaceutical preparations as per requirement.
From drug substance to Pharmaceutical Dosage forms
Factors affecting Dosage Form Design
1. Drug Consideration In Dosage Form Design
• Organoleptic considerations such as physical appearance,
taste, smell, tactility, size, & “Pharmaceutical elegance”.
• Physicochemical properties of drug substance such as type
(crystalline/ polymorphs/ amorphous / hygroscopic),
melting point, boiling point, solubility, pKa, lipophilicity,
reactivity, flow behaviour, rheological behaviour etc.
• Stability of drug substance. Oxidation / hydrolysis,
photolysis, rate of degradation (pH stability profile).
• Determining Drug Formulation Stability – Compatibility
Active vs. active vs. excipients vs Container.
• Prevention Against Microbial Contamination
From drug substance to Pharmaceutical Dosage forms
Factors affecting Dosage Form Design
2. Therapeutic Considerations In Dosage Form Design
2.1 Nature of the disease or illness. Chronic / acute
2.2 Age of the Patient: Infants /children / adults.
3. Biopharmaceutics Considerations
3.1 PK profile of drug:
Where/how well is the drug absorbed?
Where/how the drug is distributed, metabolized & excreted?
What is biological half life of drug?
3.2 Intended site of action: Systemic / local
3.3 Intended onset of action: Immediate / sustained /delayed.
From drug substance to Pharmaceutical Dosage forms
THANK YOU
FOR
YOUR ATTENTION..
Questions?
