Powders for External Use PDF

Powders for External Use  Powders with or without medicament are frequently applied to the skin. Dusting powders contain one or more substances in fine powder and may be dispensed as single dose or multi-dose preparation. They are used to treat a variety of skin condition to sooth skin...

Powders for External Use  Powders with or without medicament are frequently applied to the skin. Dusting powders contain one or more substances in fine powder and may be dispensed as single dose or multi-dose preparation. They are used to treat a variety of skin condition to sooth skin. Examples are antifungal powders for athletes foot or talc dusting powder for the prevention of chafing and skin irritation, zinc oxide and starch are added to formulations to absorb moisture and talc is used for lubricant properties. Talc, kaolin and other natural minerals materials are liable to contamination with bacteria such as Clostridium tetani, C. Perfringens and  These ingredients should be sterilized by dry heat or the final product should be sterilized. Dusting powders should be sterilized if they may be applied to large areas of open skin or wound. They should not be used, where there is a likelihood of large volume of exudates, as hard crust will form.  Preparing powders for external use: A sieve size of 180 µm should be use to obtain the finely divided powder. The constituents should be mixed using the “doubling up” method. Shelf life and storage for powders for external user: Dry powders should remain stable over along period of time if packaged and protected from the atmosphere, for extemporaneously prepared products, a maximum expiry of 4 weeks.  Containers for powders for external use: Powders for external used may be packed in glass, metal or plastic containers with a sifter-type cap. Some are also available commercially in pressurized containers containing other excipients such as propellant and lubricants. Special labels and advice for powders for external use: These include “for external use only” and “store in cool, dry place”. Example of official powders for external use include zinc oxide dusting powder compound BP, chlorhexidine dusting powder BP, and talc dusting powders BP. Proprietary examples of powders for external use include antifungal, antibacterial.  Insufflations: Insufflations are medicated powders which are blown into regions such as the ear, nose and throat using insufflators. The use of traditional insufflations declined because they were nor very acceptable, being more inelegant and less convenient to apply than other topical preparation. A second problem was that if the powder contained a drug which had systemic activity. It was difficult with the conventional insufflators to ensure that the same dose was delivered on each occasion. Some potent drugs such as sodium cromoglycate are now presented in this way, because they are rapidly absorbed from lung.  Summary: A powder may be defined as solid mater as in a finely divided state. Granules are powders agglomerated to produce larger free-flowing powder. Powder for internal administration will comprise the active ingredient with excipients. Bulk powder can be dispensed to the patient not necessary in accurate dose. Individually wrapped powders are used to supply some potent drugs. Some preparations are supplied to the pharmacy as granules, for reconstitution immediately before dispensing.  Particles size of a powder is described using standard descriptions. Powders for external use with or without medicaments. A sieve size of 180 µm should be used to obtain the finely divided powder. Dry powder should remain stable over a long period of time if packaged and protected from the atmosphere. Insufflations are medicated powders, which are blown into ear, nose and throat. Labels should include “for external use only” for powder for external use and store in cool dry place. Tablets Dosage Forms In December 1843 a patent was granted to the Englishman William Brockedon for a machine to compress powders to form compacts. This very simple device consisted essentially of a hole (or die) bored through apiece of metal within which the powder was compressed between two cylindrical punches, one was inserted into the base of the die and at a fixed depth, the other was inserted at the top of the die and struck with a hammer. The tablet may be defined as solid preparation each contained a singe dose of one or more active ingredients and obtained by compressing uniform They are intended for oral administration, some are swallowed whole, some after being chewed, some are dissolved or dispersed in water before being administered and some are retained in the mouth, where the active ingredient is liberated. Thus a variety of tablets exists and the type of excipients and also the way in which they are incorporated in the tablet varies between the different types. Tablets are used mainly for systemic drug delivery, but also for local drug actions. For systemic use, the drug must be released from the tablet, i.e. normally dissolved in the fluids of the mouth, stomach or intestine, and thereafter be absorbed into the systemic circulation by which it reaches its site of action, Tablets can be formulated for local delivery of drugs in the mouth or gastrointestinal tract or can be used to increase the pH of the stomach.