Powder cutaneous application

In the eighth edition of the European Pharmacopoeia cutaneous preparations are classified as liquid preparations for cutaneous application, semisolid preparations for cutaneous application and powders for cutaneous application [4]. 

Powders for cutaneous application consist of solid, loose, dry particles with a varying fineness. They may contain one or more active substances and excipients. 

The solid phase contains solid substances which are dispersed in a liquid phase or a semisolid base. Powders for cutaneous application cmisist only of a solid phase. The solid substances can be active substances or excipients. 

Act as filler material powders for cutaneous application sometimes need a filler... 

Talc is a silicate often used in powders and suspensions for cutaneous application. It is a fine substance that consists mainly of magnesium silicate, but also contains some aluminium silicate. It has good flow properties and adheres well to the skin. It has a very low water absorbing capacity. A disadvantage of talc is the chance on formation of granulomas if it ends up in wounds. The combination of talc and zinc oxide in combination with water or other volatile solvents results in cooling of the skin. The cooling is the result of an increased surface area which allows water to evaporate more easily. 

Powders for cutaneous application are consisting of one or more solids forming the base (see for example Table 12.18). 

European Directorate for the Quality of Medicines (EDQM) (2014) Monographs Liquid preparations for cutaneous application. Powders for cutaneous application. Semi-solid preparations for cutaneous application. Patches, transdermal. European Pharmacopeia, 8th edn. Council of Europe, Strasbourg... 

A jar is defined as a container, without a pronounced neck, with a wide opening at the top and a more-or-less flat bottom . Jars are frequently reclosable and generally suitable for semisolid and solid pharmaceutical forms [26]. An important difference between a bottle (Sect. 24.4.1) and a jar, is that the jar does not have a neck. The jar for tablets is named separately as a tablet container. Ajar with a sifter top is used for powders for cutaneous application. 

As a powder containing 1% w/w clotrimazole for cutaneous application. Adult dose application to the infected area two or three times a day, continuing for 14 days after all visible signs of infection have healed. 

The potential of Ecoflex (powder) to cause acute dermal irritation or corrosion was assessed by a single topical application of the test substance to the intact skin of rabbits according to OECD guideline 404. After removal of the patch, the application area was washed off and cutaneous reactions were assessed for 72 h. No cutaneous reactions were observed. Hence, Ecoflex (powder) is not irritating to skin. 

Holland evaluated skin reactions to CR in humans following application of CR in graded quantities as CR powder or as dry material moistened with saline. Erythema was noted in 10 min and faded on removal of test article. When moistened, CR resulted in marked irritation. No swelling or vesication was evident, even under adverse conditions. It was concluded that CR is capable of producing acute cutaneous discomfort. In comparing the results with similar studies on CS and CN, Holland concluded that all reactions to CR are mild and transient compared to that of CS, which resulted in an erythema of greater duration and to that of CN, which produced blistering. ... 

Solid particles should be small enough not to be felt when being applied onto the skin of the patient. The Ph. Eur. doesn t give detailed guidance for particle size in the chapters for cutaneous dosage forms (see Sect. 12.2) just that it has to be suitable for application. A maximum particle size of 90 pm in powders, hydrophobic and hydrophilic ointments and in creams is generally accepted and therefore recommended. 

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