Basic knowledge of drug formulation and drug delivery devices

1. DOSAGE FORMS
Amit Kumar
Assistant Professor
Pharmacology

2. DRUG DOSAGE FORMS
Definition: It is form of drug in which drug molecules are
delivered to sites of action within the body.
The need for dosage forms:
A. Accurate dose.
B. Protection from gastric juice.
C. Masking taste and odour.
D. Placement of drugs within body tissues.
E. Sustained release medication.
F. Optimal drug action.
G. Insertion of drugs into body cavities (rectal, vaginal)

3. FORMULATION
• It is the recipe by which drug is prepared.
It contains list of
 Active ingredients (the drug)
 Excipients
 Vehicles
 Flavoring agents
 Preservatives , with their required amount.

4. • Excipients-
Pharmacologically inert substances which are added to
the pharmaceutical preparation either
1. TO ADD BULK to active drug or
2. TO mask the unpleasant taste
e.g. Lactulose, Calcium Lactate, Starch etc.

5. • Vehicles-
• Substances which are used to dissolve or suspend the
drugs in a pharmaceutical preparation e.g. sugar syrups,
cherry syrup, gum acacia.

6. Dosage forms of Drugs
Solid Liquid
Semisolid

7. Solid dosage form
1. Powders
 Simple or mixture of drugs in a dried and finely pulverised form intended for
external and systemic use.
 Simple powder (one active drug) – glucose powder
 Compound powder (more than one active drug) - ORS

8. Effervescent Powders
 Powdered drugs mixed with sodium bicarbonate, citric acid or lactic acid.
 Effervesce with evolution of CO2 when dissolved in water.
E.g.- ENO Fruit salt
 Same formulation in tablet form is called DISPERSIBLE TABLET
 E.g.- Disprin

9. 2.Granules:- Small aggregates of powder held together by
binding agent.
e.g.-Vitamin D3 granule

10. 3. Tablets:-
These are powdered or granulated form of drugs compressed under
heavy pressure into a round or disc like shape suitable for swallowing.
Active substance + Excipients
o Ordinary Tabs:- uncoated compressed tab.
o e.g.- Paracetamol, Aspirin tab.
o Sugar coated tabs:- Coated over by sugar to avoid bitter taste.
o e.g.-Tab. ,Metronidazole
o Film coated Tabs:- Coated with thin layer of
polymer to masked unpleasant taste
o .e.g.-ceftum (cefuroxime film coated Tab)

11. o Enteric coated Tab:- Coating is resistant to gastric acid. Dissolves at
intestinal alkaline pH.
e.g.-Diclofenac-EC (Diclofenac enteric coated tab)
o Sublingual tablets – Absorbed through the oral mucosa.
e.g.- GTN

12. o Sustained release/retard/ long Tab:- Aggregated drug
particles have individual coating with different types of inert resins
so that each type of coating dissolves at different time interval .
o Drug is released slowly over specific prolonged period of time.
Advantages:-
–Increase the duration of action of the drug
–Decrease the frequency of drugs administration ,less side effects.
–Improve patient compliance
E.g.- Diclonac-SR (Diclofenac sod. Sustained release)

13. o Chewable Tab:- suitable for large size tab.
e.g.- chewable albendazole tab
o Dispersible tab:- disintegrates rapidly when placed in liquid to form stable
suspension
Advantages:-
1. fast onset of action
2. useful for children and elderly who find difficulty to swallow a tab.
e.g.- Disprin (dispersible aspirin tab.)
o Lozenges:- Tablet contain drug with sugar and gum, and is meant for chewing
or sucking for providing local effects in mouth
e.g.- various cough lozenges ,like strepsil.

14. 4.Capsules:- Solid form where ingredients are enclosed in a stable shell
(gelatin/plant polysaccharides /modified form of starch) and are meant for
swallowing.
• Hard gelatin :-contain dry powder e.g.-vit B complex
• Soft gelatin :-active ingredient suspended in oil e.g.-vit-E

15. Spansule :- Long acting capsules Same as long tab. Spansule
can be noticed as coloured beads of drug inside the cap. These
beads coated with different resins which dissolve at different
time intervals
e.g.- ferrous sulfate spansule.

16. 5. Pellets:- These are sterile sphere formed by compression of drug powder
which are implanted subcutaneously. Drugs is slowly released for a long
duration of time.
e.g.- Testosterone pellets
6. Suppository:- solid dosage form,cylindrical or cone shaped for
introduction into rectum.
e.g.- Bisacodyl suppository for constipation.

17. 7. Pessary:- vaginal suppository. e.g.-nystatin pessary for vaginal candidiasis.
8. Bougie:- A urethral suppository.
These contain the drug mixed with glycerin or gelatin or hard soap. these
remain solid at room temperature but become slippery and melt at body
temp.

18. Semi solid dosage form
1. Ointment :- Semisolid preparation contain drug in a greasy base meant for
application to skin or mucosa.
• e.g.- Silver sulfadiazine ointment
2. Cream :- Semisolid emulsion for external application .
3. Paste :- It is like ointment but no greasy base. These have some adhesive
material or a foaming agent .
• e.g.- toothpastes , ZnO paste
4. Gels :- Drug dissolved in liquid and then dispersed in some gelling agent and
usually transparent preparation.
• e.g - Contraceptive gels.

19. Liquid dosage forms
1.Syrups:- concentrated sugar solution containing the drugs + flavoring
agents. Administer bitter, unpalatable drugs.e.g.-cough syrups, vitamin syrups.
2.Liquors:- aqueous solution of medically substance which are either gases or
are volatile or which sublimate. e.g.-liquor ammonia ,H2O2 Solution.
3.Linctus:- Viscous syrupy liquids preparation which should be sipped slowly
to allow it to trickle down the throat. These contain some demulcent like menthol
e.g.-cough linctus.
4.Mixture:- preparation containing one or more soluble /insoluble ingredient
for oral use.e.g.-Mgso4 mixture for constipation.

20. 4. Tincture:- These are hydroalcoholic solutions of inorganic substances, which
depending on the methods of manufacturing are called tinctures. e.g.- tincture
iodine,
5.Emulsion:- Mixture of 2 immiscible liquids
e.g.-cod liver oil emulsion
6. Suspension:- one or more insoluble ingredient homogeneously distributed in
liquid.e.g.-antacid suspension
7. Elixir:- clear, Pleasants flavored liquid of potent drugs dissolve in water and
ethanol e.g.-promethazine elixir for cough

21. 8. Liniment :- liquid or semi fluid preparation to be rubbed on
skin e.g.-liniment turpentine
9.Lotion :- without rubbing. e.g.- zinc calamine lotion

22. 10.Spray:- drug is delivered in the form of fine droplets .e.g.-diclofenac(on skin)
11- Paints:- Paints are liquids for application to the skin or mucous membranes.
- Skin paints contain volatile solvent that evaporates quickly to leave a dry
resinous film of medicament.
- Throat paints are more viscous due to a high content of glycerol, designed to
prolong contact of the medicament with the affected site.

23. 12.Enema:- liquid preparation to be admistered into rectum.
Evacuation enema :- to evacuate the bowel content.
e.g.-soap and water enema
Retention enema :- The drug containing fluid is retained in the rectum.
e.g. :- Prednisolone enema for ulcerative colitis.
13.Injections :- sterile solution /suspension of drugs in suitable solvent +
preservatives meant for parental use.
e.g.- injection solution:-regular insulin
injection suspension – lente insulin

24. • Depot Injection :- Longer acting injectable preparation.
• Ampoule:- small,sterile,sealed glass container containing drugs solution
for injection, it contain single dose of drug.
• e.g.- atropine ,adrenaline.
• Vial :- small,sterile,glass bottle closed with a stopper containing drugs in
powder form/ aqueous solution/ suspension for injection, It contains single or
multiple doses of a drug
• e.g.- lignocaine

25. DRUG DELIVERY DEVICES

26. TRANSDERMAL THERAPEUTIC SYSTEMS
• Devices in the form of adhesive
patches of various shapes and
sizes (5-20cm2)which deliver the
contained drug at a constant rate
into systemic circulation via the
stratum corneum.
• Drug is contained in reservoir
between an occlusive backing
film and a rate controlling
micropore membrane.

27. • Drug is delivered at the skin surface by diffusion.
• Rate of drug delivery through micropore membrane is less than the
slowest rate of absorption from the skin , hence drug is delivered at a
constant and predictable rate irrespective of application site.
• Action lasts for 1-7 days.
• Sites – chest, abdomen, upper arm, lower back, buttock, mastoid region.

28. Advantages Disadvantages
1) Convenient.
2) Increased patient compliance.
3) Avoids first pass metabolism.
4) Improves bioavailability.
5) Decrease the administered
dose.
6) Decrease side effects.
7) Easy to discontinue in case of
toxic effects.
1) Expensive.
2) Local irritation (site should be
changed).
3) Not for large molecular sized
drugs.
4) Can not deliver drugs in
pulsatile fashion.

29. Examples
1) Glyceryl tri nitrate.
2) Fentanyl.
3) Nicotine.
4) Estradiol.
5) Isosorbide dinitrate.
6) Hyoscine.
7) Clonidine.
8) Rivastigmine.
9) Testosterone.
10) Oxybutinin.

30. Transderm-SCOP (Scoplamine)
Used for motion sickness Hydrogel transdermal patch:
Used in treatment of burns

31. INSULIN PEN
• An insulin pen is used to inject insulin for the treatment of diabetes.
• Advantages-
• More convenient and easier to transport
• Repeatedly more accurate dosages
• Easier to use
• Less injection pain
• Disadvantages- usually more expensive than using the traditional vial and
syringe method;

32. INSULIN SYRINGES
• Insulin syringes are made specifically for self injections
• have friendly features: shorter needles, as insulin injections are
subcutaneous (under the skin) rather than intramuscular,
• finer needles for less pain and markings in insulin units to simplify
drawing a measured dose of insulin.

33. INSULIN PUMPS
• An insulin pump is a medical device used for the administration of insulin in the
treatment of diabetes mellitus, also known as continuous Subcutaneous
insulin infusion therapy.
• A traditional pump includes:
controls,
processing module,
batteries
a disposable reservoir for insulin (inside the pump)
a disposable infusion set, including a cannula for subcutaneous insertion
tubing system to interface the insulin reservoir to the cannula.

36. INTRACATH
• A plastic tube, usually attached to the puncturing needle,
inserted into a blood vessel for infusion, injection, or pressure
monitoring.

37. INFUSION SET
• I.V infusion sets are safe devices for delivery of intravenous
fluids and drugs to patients. This device enables the practioner
to administer medication at a set rate compatible with patient’s
age, sex, body weight.

38. SPACER
• A spacer device is a plastic cylinder, designed to make a metered-
dose inhaler easier to use.
• Many people find it difficult to co-ordinate pushing down the
canister of their inhaler with breathing in deeply, so a spacer device
is a useful way to remedy this problem.
• The spacer device also helps to slow down the aerosolised
particles that you breathe in, helping them to get down into the
lung.
• Spacer devices are commonly used in children.

39. SPACER

40. • Used for Asthma, Bronchitis Chronic obstructive pulmonary diseas
• Salbutamol , Ipratropium bromide and Terbutaline bromide is usually used
with inhaler.
ROTAHALER

41. NEBULIZER
• A nebulizer is a drug delivery device used to administer medication
in the form of a mist inhaled into the lungs.
• Nebulizers are commonly used for the treatment of Asthma, COPD
and other respiratory diseases or disorders.

42. NASAL SPRAY
• Used as local treatments for conditions such as Nasal Congestion and
Allergic rhinitis
• Nasal delivery route is preferred because it provides an agreeable
alternative to injection or pills
• Influenza vaccine is available in the form of a nasal spray, Corticosteroid
Oxyametazoline , Phenylephrine , Xylometazoline is available nasal
spray

43. Nasal spray

44. Metered-dose inhaler
• Device that delivers a specific amount of medication to the Lungs
• It is the most commonly used delivery system for treating asthma, chronic
obstructive pulmonary disease (COPD) and other respiratory diseases.
•The medication in a metered dose inhaler is most commonly
a bronchodilator, corticosteroid

45. SYRINGE
• A syringe is a simple pump consisting of a plunger that fits tightly in a
tube.
• The plunger can be pulled and pushed along inside a cylindrical tube
(called a barrel), allowing the syringe to take in and expel
a liquid or gas through an orifice at the open end of the tube.
• Syringes are often used to administer injections, insert intravenous drugs
into the bloodstream, apply compounds such as lubricant and measure
liquids.

46. OCUSERTS
• Thin elliptical micro units that
contain the drug in a reservoir
from which the drug is slowly
released through a membrane
by diffusion at a steady rate.
– Example –pilocarpine ocuserts.
It lasts for 7 days and placed at
lower palpebral conjunctiva.

47. Progestasert
• This is an intrauterine device which is inserted
into uterus where it delivers progesterone
constantly at a specific rate for a period of one
year.
– Release at a rate of 60g/d progesterone for one year.