Pharmaceutical Powders
Session 8: Pharmaceutical Powders
Total Session Time: 120 minutes
Pre-requisites
Learning Tasks
By the end of this session students are expected to be able to:
Resources Needed:
SESSION OVERVIEW
|Step |Time |Activity/ |Content |
| | |Method | |
|1 |05 minutes|Presentation|Introduction, Learning Tasks |
|2 |15 minutes|Brainstormin| Introduction to Powders |
| | |g | |
| | |Presentation| |
|3 |10 minutes|Presentation|Production of Powders |
|4 |30 minutes|Presentation|Preparation and Mixing of Powders |
|5 |30 minutes|Presentation|Bulk and Divided Powders |
|6 | |Small group |Advantages and Disadvantages of |
| |20 minutes|discussion |Powders |
| | |Presentation| |
|7 |05 minutes|Presentation|Key Points |
|8 |05 minutes|Presentation|Evaluation |
SESSION CONTENTS
STEP 1: Presentation of Session Title and Learning Tasks (5 minutes)
READ or ASK students to read the learning tasks and clarify
ASK students if they have any questions before continuing
STEP 2: Introduction to Powders (15 minutes)
|Activity: Brainstorming (5 minutes) |
| |
|ASK students to brainstorm on the following question: |
| |
|What is a pharmaceutical powder? |
| |
|ALLOW few students to respond? |
| |
|WRITE their responses on the flip chart/ board |
| |
|CLARIFY Al,0.++23.2+0000.nd SUMMARISE by using the content below |
chemicals in dry form intended for internal or external use.
o Dosage forms e.g. dusting powders
o Starting materials for other dosage forms e.g. tablets and capsules
in the finished dosage form
of powders
o Number of constituents
mixed together
o Mode of application
o Packaging
STEP 3: Production of Powders (10 minutes)
o Precipitation
o Crystallization
o Spray-drying
o By use of equipment such as course crushers, grinders, and mills
STEP 4: Preparation and Mixing of Powders (30 minutes)
o Preparation of powders involves
o Particle size reduction (all ingredients) to the same range in order
to prevent demixing or segregation
➢ Trituration (using mortar and pestle)
➢ Pulverization by intervention (for gummy or materials difficult
to grind)
➢ Levigation
o Sieving
o Weighing of each ingredient
o Mixing
o Packaging
o Mixing is as an operation in which two or more components in a
separate or roughly mixed condition are treated so that each particle
lies as nearly as possible in contact with a particle of each of the
other ingredients
o For mixing to occur the individual particles must be redistributed
repeatedly within the bulk, either by tumbling, shearing, scooping,
kneading or impaction.
o Powders are mixed to obtain homogeneity. Equipment used for mixing are
known as mixers
o For small scale mixing e.g. in compounding, equipments used for mixing
are;
o For large scale mixing e.g. in industrial production, large mixers
including
➢ tumbler mixers,
➢ shear mixers,
➢ ribbon mixers,
➢ impact mixers etc are employed
the product
single mixer)
o Methods used in mixing powders
o Free flowing mixtures
o Cohesive mixtures
o Ordered mixtures
o Packaging of Powders
STEP 5: Bulk and Divided Powders (30 minutes)
Bulk powders
wide mouth jar, perforated or sifter top cans and aerosol containers)
o Powders used in a dry form e.g. dusting powders, insufflations,
dentifrices
o Powders to be dissolved in water before use e.g. antacid powders,
douche powders
o Powders for reconstitution e.g. oral antibiotic powders, powders for
injection (powders for injection may also be supplied as divided
powders)
powders for external use
o Bulk Powders for Internal Use
finely divided powders or effervescent granules
water or mixed with soft foods, e.g., applesauce, prior to administration
powders
o Oral Powders
effervescent granules
making tablets or capsules (because of better flowability of granules
compared to powders)
o Oral powders are finely divided powders or effervescent granules
intended to be suspended or dissolved in water or mixed with soft
foods, e.g. applesauce, prior to administration
sodium biphosphate in addition to the active ingredients
base reaction
the taste of salty or bitter medications.
containers to protect it against the humidity of the air
Examples of oral powders are antacids and laxative powders
o Bulk Powders for External Use
in sifter top containers
Classes of Bulk powders for External Uses
very fine state of subdivision to avoid local irritation
either starch, kaolin or talc are used in the formulation
o Talc and kaolin are commonly used because they are chemically inert
o Dusting powders are applied to various parts of the body as
lubricants, protective, absorbents, antiseptics, anti-pruritics, anti-
bromhidrosis agents, astringents and antiperspirants
Characteristics of Dusting Powders
irritants
Types of Dusting Powders
o They are for superficial skin conditions and for antiseptic, anti-
pruritic, astringent, antiperspirant, absorbent, protective and
lubricant purposes e.g. zinc and salicylic acid dusting powder,
clotrimazole dusting powder, starch and talk dusting powder
o These are sterile powders used in body cavities for treatment of major
wounds such as burn wounds and umbilical cords in infants.
o They are medicated finely divided powders for application into body
cavities (ears, nose, throat, vagina) by means of a device known as
“insufflators” or powder blower
o Produce local effect e.g. when applied into ears or systemic effect
e.g. when inhaled into the lungs and absorbed
o They are packaged in
o Insufflators (blowers) –for non potent drugs as it is difficult to
obtain uniform doses
o Pressurized aerosols –for potent drugs where the dose is adjusted
applied through a metered valve. Pressurized aerosols are also used
for administration of micronized powders
o Snuffs are finely divided solid dosage forms of medicament that are
inhaled into the nostrils for antiseptic, bronchodilator, decongestion
actions
o These are powders that are completely soluble
o They are dissolved in water before they are used as antiseptics or
cleansing agents for body cavities e.g. vaginal use
o Powder triturates are dilutions of potent medications prepared by
mixing them well with a suitable diluent in a definite proportion by
weight .E.g. atropine sulfate in a lactose diluent
o These are dental cleansing powders
o They are powder prepared for use with the help of a tooth brush for
cleansing surfaces of the tooth
o They are available in forms of fine powders and pastes
o The powders contain
o a suitable detergent or soap
o mild abrasive substance e.g. calcium sulphate, magnesium carbonate,
sodium carbonate in fine powder;
o binder
o opacifiers
o humectants
o colouring agent
o sweetening agent e.g. saccharin sodium
o suitable flavour e.g. peppermint, clove oil
o Divided powders are similar formulations to bulk powders but doses are
individually weighed and separately wrapped (packaged)
o Divided powders are dispensed in the form of individual doses and
generally are dispensed in papers, properly folded
o Traditionally in papers (unsatisfactory for most products, especially
if the ingredients are hygroscopic, volatile or deliquescent)
o Modern packaging materials of foil and plastic laminates have replaced
paper wrapping
o They also may be dispensed in metal foil, small heat-sealed plastic
bags or other containers
o After weighing, comminuting and mixing the ingredients, the powders
must be divided accurately into the prescribed number of doses
o In order to achieve accuracy consistent with the other steps in the
preparation, each dose should be weighed individually and transferred
to a powder paper
o Following completion of this step, the powder papers are folded
o Packets
o Cachets
o Powders for injection (may be bulk or divided powder)
o Oral (Effervescent) powders or granules (may be bulk or divided)
with soft food
reaction (effervescence)
STEP 6: Advantages and Disadvantages of Powders (20 minutes)
|Activity: Small Group Discussion (10 minutes) |
| |
|DIVIDE students into small manageable groups |
| |
|ASK students to discuss on the following question |
|What are advantages and disadvantages of powders? |
| |
|ALLOW students to discuss for 15 minutes |
| |
|ALLOW few groups to present and the rest to add points not mentioned |
| |
|CLARIFY and SUMMARIZE by using the contents below |
o More stable than liquid dosage forms
o Rapid dissolution and absorption
o Offer rapid onset of action
o Easy to carry
o Flexibility of compounding/manufacturing
o Convenient for children and elderly
o Available for internal and external use
o Difficult to measure doses (leading to inaccurate dosing)
o Not suitable for bitter and nauseating drugs
o Not suitable for corrosive oral drugs
o Difficult to mask unpleasant organoleptic properties (taste, odour)
o Time consuming in dispensing
o Not suitable for hygroscopic drugs
o Not suitable for deliquescent drugs
o Volatile drugs difficult to dispense
STEP 7: Key Points (5 minutes)
chemicals in dry form
of other dosage forms
powders, divided powders, powders for external use or powders for
internal use
insufflations, snuffs, douche powders and triturates
doses. Potent drug powders are packed as divided powders.
powders
STEP 8: Evaluation (5 minutes)
References
Aulton M.E & Kevin M.G, Eds: (2013) Pharmaceutics: The design and
manufacture of medicines, (4th ed.) Churchill Livingstone
Gennaro, R. A, et.al (eds)( 1995) Remington: The Science and Practice of
Pharmacy, Volume I & II, (19th ed.) Mack Publishing Company, Easton,
Pennsylvania 18042
Liebsch, B et al. (1988): Tanzania Pharmaceutical Handbook, Dar es Salaam
University Press.
Lund, W. Editor (1994). The Pharmaceutical Codex, Principles and Practice
of Pharmaceutics 12th Edition: The Pharmaceutical Press, London
Polderman, J (1990) Introduction to Pharmaceutical Production: Novib, The
Hague
Rawlins E.A, Editor: (1977) Bentley’s Textbook of Pharmaceutics, (8th
ed.). Baillie're Tindall
Schmidt, O.(2000) Pharmaceutical Quality systems, Interpharm Press,
Colorado.
Shayne C et al. (2008), Pharmaceutical Manufacturing Handbook: Production
and processes, John Wiley & Sons
Watson, D. G., (1999) Pharmaceutical Analysis: A Textbook for Pharmacy
Students and Pharmaceutical Chemists: Churchill Livingstone, Edinburgh
Unataka kutumiwa notes hizi kupitia WhatsApp?Kwa notes zilizopangiliwa vizuri kwa kusoma offline au PDF, bonyeza kitufe hapa chini. Ujumbe wenye Level, Semester, Module na Topic utaandaliwa moja kwa moja.TUMIWA NOTES WHATSAPP
