Powders And Granules Flashcards
Granules
Are intermediate products
Granules
Size = 0.2 - 4mm
Intermediate = 0.2 - 0.5mm
Powders
Size= 0.1 - 10,000 micrometre
Pharmaceutically, 0.1 - 10
Trituration
For both comminution and mixing of powders
Spatulation
Mixing small amounts of powders using a spatula on a sheet of paper or ointment slab
Tumbling
Mixing powders in a vertical rotating chamber sometimes containing powdered blades
Sifting
Passing powders through a sift
Not suitable for incorporating potent drugs into powders
Powders for internal use
May contain one(simple) or two(compound) medicaments with or without excipients.
Divided powders
Single doses of powdered drugs.
It’s a more accurate dosage form than bulk powders
Bulk powders
Package in wide-mouthed glass or plastic jar
Bulk powders
Ingredients are relatively non- toxic medicaments with a large dose
Bulk powders
Ingredients are usually antacids, dietary supplements, laxatives and a few analgesics
Types of powders
- Powders for internal use
- Powders for external use
- Special Powders
Powders for internal use
- Divided powders - simple, compound, and powders in a cachet
- Bulk powders - antacid powders and laxative powders.
Powders for external use
- Dusting powders - medicated and surgical
- Tooth powders
- Douche powders
- Insufflators
Special powders
- Eutectic powders and explosive powders
- Effervescent powders
External powders
Dusted on affected area
Dusting powders
Free flowing very fine powders containing antiseptic, antiperspirant, astringent, lubricants, absorbents, and antipiuritics
Surgical dusting powders
Free from microorganisms and intended for deep wounds.
Surgical dusting powders
Antimicrobial agents - chlorhexidine and hexachlorophene
Douche powder
Maybe formulated also for nasal, otic, or ophthalmic use
Ph= 3.5 - 5
Effervescent powders
Supplied as either granules or powder of salts
Ways to avoid effervescence in powders
1.if in dosage form , no granulation is required
2. If, as a divided dose, effervescence ingredients are enclosed separately
3. Prepare them in granules form
Eutectic powders
Camphor, thymol, phenol, menthol,salol, acetanilide and choral hydrate
Eutectic powders
Problem can be solved by using starch, talc, lactose, light magnesium carbonate to prevent dampness
Explosive powders
- Bromine+alcohol
2.chlorates+ bisulphite - Chloric acid + bromide
Granules
Intended for oral use
GranulesG
Used for low-toxicity, high-dose drugs
Granules
Are presented as single dose or multi dose preparations
Effervescence =
Carbonate/ BICARBONATE + acid( citric acid / tartaric acid)
Good effervescence
Citric acid monohydrate +tartaric acid in ratio 1:2
Effervescence
Citric acid monohydrate is not used alone because it results in a sticky mixture that won’t be granulated easily.
Effervescence
Tartaric acid isn’t used alone because it results in granules that are too friable and crumble easily.
Powders and granules for syrup
Syrups may contain sucrose conc. at about 45%( at keast)
Importance of powders
- They are more stable than liquid dosage forms;hence, many antibiotics and injections as powders
Powders
- Easy to swallow than capsules and tablets
Importance of powders
Powders possess good chemical stability
Powders
They are in the form of small particles; hence, they offer a large surface area and are rapidly dissolved in the gastrointestinal tract, minimising the problem of local irritation.
Powders
They are highly compatible as compared to liquid dosage forms
Powders
Manufacturing is economical
Powders
Not suitable for drugs unstable in normal atmospheric conditions
Powders
Not suitable for drugs inactivated in the stomach . Such drugs should be in the form of a tablet and enteric coated.
Powders
Not suitable for bitter, nauseating, and corrosive drugs, if are meant for oral administration
Powders
Masking unpleasant taste maybe difficult
Granules
Other categories include coated granules, gastro- resistant granules, and modified release granules
