1. Pharmaceutical Dosage Forms-1 Lecture 1: Introduction

2. Pharmaceutics Pharmaceutics is the science of dosage form design.
There are many chemicals with known pharmacological properties but a raw chemical is of no use to a patient.
Pharmaceutics deals with the formulation of a pure drug substance into a dosage form

3. Active Drug Substance (Active pharmaceutical ingredient - API)
Chemical compound with pharmacological (or other direct effect ) intended for use in diagnosis, treatment or prophylaxis of diseases.
International non-proprietary names (INN, generic names)

4. Drug names
A chemical name - the scientific name of the drug chemical. This is mainly used by researchers, but is sometimes shortened and used by health workers instead of the generic or brand name.
A generic name - the name that is adapted from the chemical name and is shorter and easier to say. This is usually decided by the World Health Organization and is also called the international non-proprietary name (INN).
A brand or proprietary name - the name chosen by the producer of the drug. This is short and easy to remember, to encourage people to ask for the drug by that name.

5. API is not use as such. Why???
API handling can be difficult or impossible (e.g., low mg and g doses)
Accurate drug dosing can be difficult or impossible
API administration can be impractical, unfeasible or not according to the therapeutic aims
Some API can benefit from reducing the exposure to the environmental factors (light, moisture…), or they need to be chemically stabilised due to the inherent chemical instability

6. API is not use as such. Why???
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
API can have unpleasant organoleptic qualities (taste, smell – compliance!)
Administration of active substance would mean to have no chance for modification (improvement) of its PK profile

7. From drug substance to pharmaceutical preparation
Besides the choice of the active drug substance, you need to also make a responsible decision regarding the route of administration and the DOSAGE FORM (drug delivery system) – wrong choice can cause failure of therapy
You should also be able to handle and administer the drug properly or advise the patient about it – wrong use can cause failure of therapy

8. Excipients (Additives)
Excipients (inactive pharmaceutical ingredients)
Its selection depends on technological, biopharmaceutical and/or stability reasons.
Diluents/fillers, binders, lubricants, coatings, preservatives, colorants and flavouring agents

9. Pharmaceutical dosage form
Determines the physical form of the final pharmaceutical preparation
Is a drug delivery system which is formed by technological processing (drug formulation)
Must reflect therapeutic intentions, route of administrations, dosing etc.

10. 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
(Extemporaneous Preparations)

11. 1- Pharmaceutical preparations manufactured by pharmaceutical industry
1.1- Original pharmaceutical preparations
undergo full and very extensive pharmacological/ toxicological and pharmaceutical pre-clinical and clinical development and evaluation
particularly important is the proof of effectiveness and safety

12. 1.2- Generic pharmaceutical preparations („authorised copies of original preparations“)
-Can be released after the expiration of the patent protection of the original preparation
The approval for clinical use is easier due to the prior experience with the original preparation
Must be pharmaceutically equivalent: same API, dose, pharmaceutical dosage form and the same route of administration as in original preparation
Must be clinically bioequivalent: i.e. it must be of very close PK profile as original preparation. PK parameters (Cmax, tmax, AUC) are within % range as compared with the original preparation.

13. 2- Extemporaneous Preparations
These PP are compounded individually for a particular patient according to the physician's prescription in a pharmacy licensed for compounding

14. Extemporaneous Preparations Can be Used When:
The drug in a particular dosage form is not commercially available on the market
The extraordinary low or high dose is needed (young children, elderly people, special situations – e.g., intoxications). In this case right dosage strength need not be readily commercially available for every patient
The patient suffers from the allergy on a specific excipients (e.g., lactose – a filler, some colorizing/flavouring or antimicrobial agents - parabens) or another drug appearing in the PP
Patient is unable to use a PP in its commercially available dosage form (e.g., children, elderly)

15. Classification of pharmaceutical dosage forms according to physical properties
Gaseous dosage forms
Liquid dosage forms
Semisolid dosage forms
Solid dosage forms

16. Gases Medicinal gases, inhalation/volatile anaesthetics
Aerodispersions of solid particles (e.g., antiasthmatic inhalations) or liquid particles (antiasthmatic inhalations or sprays)

17. Liquids Solutions Emulsions Suspensions
One homogenous phase, prepared by dissolving one or more solutes in a solvent
Emulsions
a dispersion system consisting of two immiscible liquids
o/w or w/o
cloudy appearance
Suspensions
A dispersion system where solid particles (dispersed phase) are dispersed in liquid phase (dispersion medium)

18. Semisolid dosage forms 1- Unshaped (without specific physical shape)
Gels -A semisolid systems in which a liquid phase is constrained within a 3D cross-linked matrix.
Creams – semisolid emulsion systems (o/w, w/o) containing more than 10% of water.

19. Semisolid dosage forms 1- Unshaped (without specific physical shape)
Ointments – semisolid dosage forms with the oleaginous (hydrocarbon), water-soluble or emulsifying base
Pastes – semisolid dispersion system, where a solid particles (> 25%, e.g. ZnO) are dispersed in ointments – mostly oleaginous (Petrolatum)

20. Semisolid dosage forms
2- Shaped
Suppositories (for rectal administration)
different shapes
Melting/dissolving at body temperature
Oleaginous (cacao butter) or aqueous (PEGs, glycerinated gelatine)
Pessaries (vaginal suppositories)
Similar as above, PEGs or glycerinated gelatine are often used as base.

21. Solid Dosage Forms Unshaped (without specific shape)
- powders for external/internal use
Shaped
Tablets
Capsules
Implants (Sterile disks inserted surgically into body tissues and designed to release drug(s) over extended period of time)
Transdermal patches
Lozenges (consists of sugar and gum to medicate the mouth and throate)

22. Classification of pharmaceutical dosage forms according to the route of administration
1) For systemic administration
Peroral (p.o)
Sublingual (S.L) and buccal.
Rectal
Parenteral
Transdermal
Inhalation

23. Classification of pharmaceutical dosage forms according to the route of administration
2) For local administration
Topical (on the skin or mucosa)
Into/onto - the eye, nose, ear
- the oral cavity
- the vagina, rectum
- the bronchi
- the skin
Local parenteral (viz Parenteral above)
Oral (local effect within GIT; antacids, adsorbents)

24. Types of Drugs
Legend Drugs: These drugs may not be dispensed by a pharmacist without a prescription from a physician.
Controlled Drugs: In addition to requiring a prescription, these drugs require additional safeguards for storage. Refills are also limited.
Over-the-Counter (OTC) Drugs: These drugs do not require a prescription.