Lotions testing

As cleansers moved to syndet bars to liquid detergent systems, they became more and more innocuous in the short term and required exaggerated exposure to elicit measurable dryness and damage response. However, as cleansers have begun to move toward active moisturization, methods traditionally associated with lotion-testing can be applied. 

The inclusion of the a routine microbial limit test in a marketed product stability protocol depends on the pharmaceutical dosage form. Typically, the test would be used only for nonsterile products, especially oral liquids, nasal sprays, and topical liquids, lotions, and creams that have sufficient water activity to support the growth of microorganisms. In contrast, tablets, powder- and liquid-filled capsules, topical ointments, vaginal and rectal suppositories, nonaqueous liquids and inhalation aerosols with a water activity too low to allow for the product to support the growth of microorganisms would not be routinely tested. 

Application to the face as lotion for acne treatment in two persons caused facial erythema and edema patch tests with benzoyl peroxide were positive. In contact with the eyes it may produce irritation, and if allowed to... 

Topical, Ophthalmic, and Otic Preparations Clarity, homogeneity, pH, resus-pendability (for lotions), consistency, viscosity, microbial bioburden, and water loss should be tested. For ophthalmic and otic products additional attributes should include sterility, particulate matter, and extractables. 

The blinded TEM studies rated the test materials potential to improve lipid ultrastructure as neat SEFA > neat petrolatum > lotion. However, the blinded expert scoring in this study ranked the test materials ability to improve dry skin oppositely lotion > neat petrolatum > neat SEFA. This reversal illustrates two of the roles a moisturizer can play the former showing the materials potential to effect functional improvement and biological repair, the latter showing their potential to cosmetically improve dry skin.47 Importantly, these results demonstrate that the cosmetic and functional aspects of a moisturizer s action on skin do not necessarily contribute to the same extent or need not even act in parallel for a given material or product. 

In a small test group of only five subjects erosion times of the dry skin of the calves were determined before and after four weeks of treatment with either a water-in-oil cream or a 12% lactic acid lotion (Figure 37.1). The assay was performed on four adjacent spots per leg. Spot-to-spot variation was on average less than one minute. In the majority of subjects erosions formed within two minutes. Erosion times on the legs treated with the water-in-oil cream were strongly increased, whereas the opposite legs, treated with the lactic acid lotion showed only slight improvement. This is not unexpected since alpha-hydroxy acids are known for their keratolytic activity which will weaken the... 

The elbow test involves applying products to the inside of the elbow up to six times per day for three weeks. This is a sensitive area of skin, and easily defined, which is important since this is a selfapplication test. This test is useful for products such as body lotions, etc., and also as a preliminary to a face test, where the skin is more sensitive. Each panellist serves as their own control the test material is applied to one elbow and the control material applied to the other. The panel is balanced according to sex, hand dominance, and initial skin grades of reaction. One half of the panel has the dominant hand allocated to the test material, and the other half has their dominant hand allocated to the control material. The levels of irritation elicited by the test and control treatments are compared. Subjective comments are also taken into consideration. At intervals throughout the treatment period, each site is assessed for visible signs of irritation, for example, erythema and dryness. 

The presence of certain metals such as iron, particularly in the presence of water, can act as a catalyst for many types of chemical reaction including oxidation, and iron can itself form highly colored reddish-brown complexes with many materials. A common test for the presence of iron in essential oils such as patchouli, where it can occur as a result of the distillation process being carried out in nonstainless steel equipment, is to mix the oil with benzyl salicylate. If iron is present, a reddish color develops after a few moments. Fortunately iron can quite easily be removed by treatment with citric, tartaric, or oxalic acids, with which it forms stable sequestered complexes. Compounds that show this type of discoloration can sometimes be recovered in this way if not too old, whereas products containing water (which may be the source of the iron contamination), such as alcoholic lotions, will usually show too much odor deterioration, by the time the discoloration has developed, to make recovery possible. 

This is the place to start, since most often, analytical chemists are trying to help solve someone else s problem. We need to define the solute and its matrix as well as the nature of the analytical problem. For example, in the world of pharmaceuticals, there are raw material identification and purity determinations, in-process testing, dosage-form determinations, content uniformity, dissolution testing, stability studies, bioavailability, pharmacokinetics, and drug metabolism, to name a few. Each of these analytical problems has its own specific requirements. The matrix can be a raw material, granulation, tablet, capsule, solution, lotion, cream, syrup, dissolution medium, blood serum, urine, or various body tissues and fluids. Similar definitions can be described for virtually any industrial area and problem set. These definitions will help select sample preparation, separation, and detection techniques. 

Microbiological protection of multiple-dose presentations such as liquid inhalations, nasal sprays, oral liquids, creams, and lotions is more complex. Once opened they are susceptible to microbiological contamination. If they are aqueous-based, they are in principle susceptible to proliferation of these new contaminants. To avoid this, they are formulated with antimicrobial agents or preservatives and are expected to be able to comply with preservative efficacy standards specified in the pharmacopeias. Preservative efficacy tests (not harmonized) are described in Section 51 of the USP and Section VIII. 14 of the PhEur (Fig. 3). 

In 11 patients allergic to topical minoxidil lotion, patch tests showed that four were positive to minoxidil itself (11). Propylene and butylene glycol are used as solvents for minoxidil in topical formulations. Nine of the 11 patients appeared to have positive patch tests to propylene glycol and one of the 11 reacted to its alternative butylene glycol. 

Dermal absorption was tested in eight women at a maximum dose of 0.0029 mg selenium/kg as selenomethionine (0.05% L-selenomethionine in a lotion). No detectable increase in serum selenium concentrations was observed but because the concentrations tested were so low, absorption cannot be ruled out (Burke et al. 1992a). Absorption of selenium disulfide was examined using a monthly 24-hour urine specimen in 16 persons who washed their hair weekly with a 1% selenium disulfide shampoo. No differences were found from control urinary selenium levels over the 1-year exposure period (Cummins and Kimura 1971). No absorption of selenium from selenium sulfide was seen in 15 persons who applied a 2.5% selenium sulfide suspension to their torsos and allowed it to remain on the body overnight (Kalivas 1993). 

Sun=100mg/Test Suspension, Sun and also Sunless Tanning Lotion (2 times a day), 3cc/Synthol into Biceps and Calf Muscles (3cc each / 12cc total)... 

---