Hey you all guys hope you all are doing good. Here is a quick reminder for you all we've completed unit 1 and after that I have provided one CHEATSHEET . If you have not seen pls go through all the notes as they're important.
INTRODUCTION TO POWDERS:
•Powder is a mixture of finely divided drug and / or chemicals in a dry form that may be intended for internal use (oral powders) or external use (topical or dusting powder). Powders represent one of the oldest dosage forms.
•Although powders are not used now-a-days extensively as a dosage form, they are widely used in preparation of various dosage forms.
•Powdered drugs can be blended with other powdered materials prior to fabrication into other solid dosage such as tablet and capsule.
•Powdered drugs are frequently added to other ingredient to make ointments, pastes, suppositories etc.
■ADVANTAGES
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| Credit:- 1mg.com |
•Powders being solid preparation are more stable than liquid and semi-solid preparations
•Convenient forms, to dispense large dose of drugs. They can become best administered in powder form by mixing them with food or drinks. •Since powders are in the form of small particles they offer a large surface area and are rapidly dissolved in the gastrointestinal tract minimizing the problems of local irritation.
•More convenient to swallow. faster dissolution and absorption than tablets or capsules.
•Powders offer a lot of flexibility in compounding incompatible solids
•They are easy to apply.
•They absorb skin moisture, which leads to reduced friction between skin surfaces, discourages bacterial growth and has a cooling effect.
•Can be applied to many body cavities such as ears, nose, tooth socket and throat
•Can be made into many different dosage formulations eg capsules, tablets, powders for reconstitution, dusting powders, bulk powders, powders for inhalation etc.
•Highly compatible compared to liquid dosage forms Manufacturing of powder is economical hence product cost is quite low as compared to other dosage form.
DISADVANTAGES
•Less convenient to carry especially bulk powders.
•Not suitable for administering potent drugs with a low dose. Difficult to mask the unpleasant taste of the drugs.
•Light fluffy powders may be inhaled by infants leading to breathing difficulties.
•Variable dose accuracy.
•Not suitable form for drug inactivated in the stomach or cause tablets.) to stomach (these should be presented as enteric-coated.
•Not suitable for bitter, nauseating and corrosive drugs, meant for
oral administration.
•Difficulty of protecting hygroscopic deliquescent or aromatic materials and not suitable for drugs which are unstable in atmospheric conditions.
•They are susceptible to physical instability normal.
CLASSIFICATIONS OF POWDERS:
They are broadly classified as;
-Bulk powders for external use
-Dusting powders
-Snuffs
-Dental powder
-Bulk powders for external use
-Dusting powders
-Snuffs
-Dental powder
-Insufflations
(☆Bulk powders for internal use.
☆Simple and compound powders for internal use)
-Effervescent granules
-Eutectic mixtures.
-Cachets
SIMPLE POWDERS
•Only one ingredient either in crystalline or amorphous form. These powders should preferable be reduced to fine powder, weighed properly and supplied in a single dose packet separately. If the drug is resistant to atmospheric conditions, it can be wrapped singly and if sensitive to those conditions, must be double wrapped (lined with waxed paper)
For example: Paracetamol.. 500mg
Method: Weigh accurately the required amount of paracetamol powder which is already in its fine state. If not, then first reduce to fine powder and weigh. Wrap each dose in white demy paper.
COMPOUND POWDERS:
•Compound powders contain two or more ingredients supplied in the form of fine state of powder in divided dose, i.e. each dose is supplied in a single packet.
For example: Aspirin - 250mg
Paracetamol - 150mg
Caffeine - 50mg
Method: Powder each ingredient and weigh required quantities. Mix them in geometric proportion and supply in divided doses. Wrap each dose in a double-wrapped paper.
DUSTING POWDER:
These are used externally for local application ,not intended for systemic action. The desired characteristics of powders include;
(a) homogeneity
(b) non-irritability
(c) free flow
(d) good spreadability and covering capability
(e) adsorption and absorption capacity
(f) very fine state of subdivision
(g) capacity to protect the skin against irritation caused by friction, moisture or chemical irritants.
•Dusting powders usually contain substances such as zinc oxide, starch and boric acid or natural mineral substances such as kaolin or talc.
•Talc may be contaminated with pathogenic microorganisms such as Clostridium tetani and hence it should be sterilized by dry heat. Dusting powders should not be applied to broken skin. If desired, powders should be micronized or passed through a sieve # 80 or 100.
•Dusting powders should preferably be dispensed in sifter-top containers. Such containers provide the protection from air, moisture and contamination as well as convenience of application.
• Currently some foot powders and talcum powders have been marketed as pressure aerosols.
•Dusting powders are employed chiefly as lubricants, protective's, absorbents, antiseptics, antipruritics, astringents and antiperspirants.
For example: Zinc oxide -20 parts
Salicylic acid -2 parts
Starch powder- 78 parts.
Tomorrow we'll see different methods for preparation of powders. So stay tuned, if you've not subscribed yet, do subscribe now for regular updates.👨🔬👩🔬
Do let me know in comment section if the topic is clear or not.🧐Thank you. Hope you enjoyed learning. 😇♥️
(☆Bulk powders for internal use.
☆Simple and compound powders for internal use)
-Effervescent granules
-Eutectic mixtures.
-Cachets
SIMPLE POWDERS
•Only one ingredient either in crystalline or amorphous form. These powders should preferable be reduced to fine powder, weighed properly and supplied in a single dose packet separately. If the drug is resistant to atmospheric conditions, it can be wrapped singly and if sensitive to those conditions, must be double wrapped (lined with waxed paper)
For example: Paracetamol.. 500mg
Method: Weigh accurately the required amount of paracetamol powder which is already in its fine state. If not, then first reduce to fine powder and weigh. Wrap each dose in white demy paper.
COMPOUND POWDERS:
For example: Aspirin - 250mg
Paracetamol - 150mg
Caffeine - 50mg
Method: Powder each ingredient and weigh required quantities. Mix them in geometric proportion and supply in divided doses. Wrap each dose in a double-wrapped paper.
DUSTING POWDER:
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| Credit:- practice.com |
(a) homogeneity
(b) non-irritability
(c) free flow
(d) good spreadability and covering capability
(e) adsorption and absorption capacity
(f) very fine state of subdivision
(g) capacity to protect the skin against irritation caused by friction, moisture or chemical irritants.
•Dusting powders usually contain substances such as zinc oxide, starch and boric acid or natural mineral substances such as kaolin or talc.
•Talc may be contaminated with pathogenic microorganisms such as Clostridium tetani and hence it should be sterilized by dry heat. Dusting powders should not be applied to broken skin. If desired, powders should be micronized or passed through a sieve # 80 or 100.
•Dusting powders should preferably be dispensed in sifter-top containers. Such containers provide the protection from air, moisture and contamination as well as convenience of application.
• Currently some foot powders and talcum powders have been marketed as pressure aerosols.
•Dusting powders are employed chiefly as lubricants, protective's, absorbents, antiseptics, antipruritics, astringents and antiperspirants.
For example: Zinc oxide -20 parts
Salicylic acid -2 parts
Starch powder- 78 parts.
Tomorrow we'll see different methods for preparation of powders. So stay tuned, if you've not subscribed yet, do subscribe now for regular updates.👨🔬👩🔬
Do let me know in comment section if the topic is clear or not.🧐Thank you. Hope you enjoyed learning. 😇♥️
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