Advantages Of Powder Powder

I. POWDERS
Powder is a mixture of finely divided drugs and/or chemicals in dry form. Powders can be used internally and externally (e.g., external applications to the skin). Dry powders, however, can be taken orally by some patients who are unable to swallow other solid dosage forms such as capsules and tablets. Although powders per se are not used extensively in therapeutics, 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 forms. Powdered drugs are frequently added to other ingredient to make ointments, pastes, suppositories, and others. Powder properties relevant to pharmaceutical formulations are singleparticle properties,

DISADVANTAGES OF THE POWDER DOSAGE FORM 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 administration. Many herbal drugs (mainly infusions in boiling water) have very bitter tastes. To overcome the unpleasant taste of the extracts, 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). 5. Powder must be a homogeneous blend of all of the components and must be of the most advantageous particle size. The particle size of a drug influences the rate of solubility in water. It may also influence the biological activity of a

A few advantages of granules over powders are listed below:
1. Granules flow better than powders. The easy flow characteristics are important in supplying drug materials from the hopper or feeding container into the tableting presses. For this reason powder mixtures are usually granulated if they are intended to be compressed into tablets. Granules also eliminate or control dust. 2. Granules increase compressibility. 3. Granules have smaller surface area than a comparable volume of powders. This makes granules more stable physically and chemically than the corresponding powders. Granules are less likely to cake or harden upon standing than are powders. 4. Granules are more easily wetted by a solvent than are certain powders, so that granules are also preferred in making solutions. Example: Principen® (ampicillin) for Oral Suspension (Squibb). Ampicillin is unstable in aqueous solution, so it is usually prepared as granules and reconstituted by a pharmacist with purified water just prior to dispensing. The granules also contain colorants, flavorants, and other pharmaceutical ingredients, so the resulting solution or suspension has all the desired medicinal and pharmaceutical features of a liquid pharmaceutical. 5. Granules produce particle-size uniformity, thus content