define powders? what are the advantage and disadvantages of powders.
Answers
A powder is a dry, bulk solid composed of a large number of very fine particles that may flow freely when shaken or tilted.
Advantages of powders:
i) Powder form is the most versatile and convenient to prescribe, compound and administer.
ii) A physician has the option to deviate from the conventional dose of a medicament according to the requirement of the patient.
iii) Powders are stable and do not enter into reaction in solid state, lesser difficulties are experienced in compounding them together,
iv) It is possible to reduce them in the desired particle size range and thus facilitate rapid absorption.
v) Less incompatibility as compared to liquid dosage form.
vi) Powders are in the form of small particles; they offer a large surface area and are rapidly dissolved n the gastrointestinal (GI) tract minimizing the problems of local irritation. Drugs that have to be given in bulk can be best administered in powder form by mixing them with foods or drinks.
vii) Whenever effervescence is desired, accurate quantities of the two reacting powders are mixed with water.
viii) It is difficult for children and infants to swallow tablets and capsules and under such circumstances drugs may be administered in powder form making them palatable by mixing with milk, fruit juice or honey.
ix) Manufacturing of powder is economic hence product cost is quite economic as compare to other dosage form.
Disadvantages of Powder
i) As compared to other dosage forms, powders are time consuming to compound.
ii) Volatile, hygroscopic, oxidizing and deliquescent drugs create obvious difficulties when dispensed as powders.
iii) Dose inaccuracy.
A powder is a dry, bulk solid composed of a large number of very fine particles that may flow freely when shaken or tilted. Powders are a special sub-class of granular materials, although the terms powder and granular are sometimes used to distinguish separate classes of material. In particular, powders refer to those granular materials that have the finer grain sizes, and that therefore have a greater tendency to form clumps when flowing. Granulars refers to the coarser granular materials that do not tend to form clumps except when wet.
ADVANTAGES OF POWDERS
1. Powder form is the most versatile and convenient to prescribe, compound and administer.
2. A physician has the option to deviate from the conventional dose of a medicament according to the requirement of the patient.
3. Powders are stable and do not enter into reaction in solid state, lesser difficulties are experienced in compounding them together,
4. It is possible to reduce them in the desired particle size range and thus facilitate rapid absorption.
5. Less incompatibility as compared to liquid dosage form.
6. Powders are in the form of small particles; they offer a large surface area and are rapidly dissolved n the gastrointestinal (GI) tract minimizing the problems of local irritation. Drugs that have to be given in bulk can be bestI administered in powder form by mixing them with foods or drinks.
7.Whenever effervescence is desired, accurate quantities of the two reacting powders are mixed with water.
8. It is difficult for children and infants to swallow tablets and capsules and under such circumstances drugs may be administered in powder form making them palatable by mixing with milk, fruit juice or honey.
Disadvantage
Powders have several disadvantages as a dosage form as described below:
1. Patient may misunderstand the correct method of use. Without clear instruction, patients may inhale through the nose a drug intended for oral administration. In oral administration, it may have to be clear whether the drug has to be dissolved first in water or taken as is.
2. It is undesirable to take bitter or unpleasant tasting drugs by oral ad-ministration. Many herbal drugs (mainly infusions in boiling water) have very bitter tastes. To overcome the unpleasant taste of the ex-
tracts, it was often told that “bitter medicine is better medicine.” This may not necessarily be true.
3. It is difficult to protect powders containing hygroscopic, deliquescent (tending to melt or dissolve in humid environment), or aromatic materials from decomposition.
4. Uniform, individually wrapped doses of powders (sachets) are required and this may increase the manufacturing expense. (It is possible to include a spoon in a packet of powder drug. This may result in inaccurate amount of drug delivered).