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Spray August 2015

The aerosol can, usually aluminum 45x154 or 53x175, may be positioned upright or arranged for inverted use in a customized holder. The stem orifice is often 2x0.020" for rapid delivery purposes. 3128 S Spprraayy MAaurgcuhs 2t 0210415 For formulators interested in numerically assessing foam stability, one device consists of a plastic plate in which two electrical terminals are embedded about 2" (50 mm) apart. Below the plate they are connected through a small battery and galvanometer. After covering the electrodes with a generous piece of filter paper, the test product is actuated so that the foam covers both terminals. As the foam coalesces, a conductive liquid will form, soaking the filter paper and electrically connecting the two electrodes and completing the circuit. This will activate the microammeter or galvanometer. In one example of a relatively unstable foam, adding a small amount of polyoxyethylene (2) cetyl or stearyl ether increased stability time from three minutes to three hours by this test method. In many cases, simply working the foam by hand or applying it to target skin or hair surfaces will provide adequate performance data. Pharmaceutical sprays continue to make up most of the sales volume in the category. Most important are antiperspirants and athlete’s foot products. The latter are usually based on Miconazole Nitrate or Tolnaftate active fungicidal ingredients, typically present at about 1% of the deposited product layer. Some versions contain up to about 8.5% talc in the complete formula. The wrong talc can agglomerate and sometimes plug aerosol valves. This propensity is minimized by using the Altaslc 400V product. A typical “talc” formulation: Miconazole “Athlete’s Foot” & “Jock Itch” Spray Miconazole Nitrate, USP (100% Basis) 0.1026% S.D. Alcohol 40-2 (Anhydrous) 6.0000% Arlacel 83 (Sorbitan Sesquioleate) 0.1500% Bentone 27 (Stearalkonium Hectorite) 0.4500% BHT (Butylated Hydroxytoluene) 0.0100% Talc - Pulverized 4.2000% Iso-butane (A-31) 89.0874% Miconazole Nitrate has about a dozen trade names, of which Micatin is the most popular. The exact amount added will be dependent upon the lot assay. The concentrate should be batched and stored under nitrogen or argon. It should be homogenized as a final step. The valve stem is 1x0.020" and the body should have a 0.025" vapor-tap. This allows a relatively low delivery rate through a mechanical break-up (MBU) 0.016" ST orifice. Pharmaceutical aerosol ingredients are always the purest commercially available, meeting strict USP standards whenever possible. The active ingredients are assayed by the marketer or contract filler. Besides formula and packaging developments, the marketer must conduct clinical and efficacy studies, product performance investigations, regulatory aspects, safety claim substantiations, patent searches, topical microbiological studies and other disciplines. Large groups of scientists and other experts are needed to bring pharmaceutical products to the market. Some products, such as topical sanitizers and disinfectants, must be studied and approved by the FDA or the U.S. Dept. of Agriculture (USDA), and this regulatory process can be very time consuming. Lastly, active ingredients used for topical pharmaceuticals must have been previously marketed since about 1965. Packaging Plain and lined tinplate, laminated C/CO steel and lined aluminum aerosol cans have been used for pharmaceutical aerosol products. The linings must be FDAapproved. There is some concern about the popular epon/phenolic linings that may contain traces of Bis Phenol A, a possible carcinogen. Despite the fact that it may be fractionally leached out by some products, to the extent of “unmeasureable” or part-per-billion (ppb.) levels in those products, there is some cause for concern as non-government organizations (NGOs) and regulators consider possible options. Trillions of these lined cans have been used with no known adverse effect. The industry has developed several possibilities for eliminating these particular can linings. (Note: For clarity, one ppb. amounts to a small drop in a 10,000 gallon tankcar.) The ideal pharmaceutical valve utilizes a conical mounting cup profile, with a polypropylene laminate. Spray products now tend to eschew actuator buttons; instead they use mounting cup covering fitments such as a “twist-to-lock” accessory and others of similar design. For foams, the “Mousse Spout” remains popular, but there are many alternatives. White remains the most popular color, followed by various shades of blue; however, other colors are frequently seen. Despite the many challenges, the future of pharmaceutical aerosols looks promising, spurred on by sophisticated sprays and foams that are favored by retailers for their high value per inch of shelf space. SPRAY Lotrimin AF Antifungal Powder Spray has been proven clinically effective in the treatment of jock itch (tinea cruris), according to the company.


Spray August 2015
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