Propylene Glycol In Concentrations Research Articles

Put a stop to perspiration

No one likes to sweat, but with hot, humid summer weather, it's difficult to avoid. And for patients with hyperhidrosis, a medical condition that causes excessive sweating, fighting perspiration becomes an important part of daily life. Fortunately, several kinds of antiperspirants are available to help. FDA defines an antiperspirant as “a drug product applied topically that reduces the production of perspiration (sweat) at that site.” Through its drug approval processes, FDA ensures that OTC antiperspirant products are safe and effective for topical administration. In contrast, deodorants are formulated to neutralize or mask underarm odor and do not prevent sweating. Because they don't contain an active ingredient such as aluminum, deodorants aren't regulated by FDA. Most antiperspirants use metallic salts, which temporarily plug the sweat ducts and reduce sweat on the skin surface. According to FDA, the product must contain an aluminum and/or zirconium salt that meets the aluminum to chloride, aluminum to zirconium, and aluminum plus zirconium to chloride atomic ratios described in the U.S. Pharmacopeia-National Formulary. Common examples include aluminum chloride, aluminum chlorohydrate, aluminum chlorohydrex polyethylene glycol, aluminum sesquichlorohydrate, aluminum zirconium octachlorohydrate, aluminum zirconium tetrachlorohydrex, and aluminum sesquichlorohydrex propylene glycol in concentrations of up to 20% or 25%. OTC products typically contain both antiperspirant and deodorant ingredients. Because aluminum salts can aggravate razor burn and cause skin irritation and acne, aluminum zirconium products—which are less likely to cause irritation—are increasingly common. Both aluminum and zirconium salts precipitate when contact with sweat raises the skin pH, plugging the sweat glands and helping the skin to stay dry. It's best to apply antiperspirants at bedtime, when the skin is dry, and they have sweat-free time to work. Applying antiperspirant after a shower isn't nearly as effective, as the antiperspirant may slide off the skin and not reach the sweat ducts. Antiperspirants are available in stick, roll-on, lotion, spray, or wipe form. All of these products are effective at preventing perspiration and the formulation used is primarily personal preference. Some antiperspirant brands are marketed as “prescription strength” or “clinical strength,” which generally means the product contains either a slightly higher active ingredient concentration or use of one of the newer active ingredients that may be more effective. These products are typically far more expensive than regular strength products and are generally needed only for patients with hard to control hyperhidrosis. Additional nonactive ingredients contained in antiperspirants include parabens (as a preservative to keep the product free of bacteria); castor, mineral, or sunflower oil to allow smooth application; alcohol; polyethylene glycol distearates (emulsifiers); butylated hydroxytoluene, which slows the deterioration of the antiperspirant ingredients once they're exposed to oxygen; and talcum powder. Fragrances are also commonly added to antiperspirants to appeal to users, though fragrance-free products are also available. Scents such as lavender and rose are often used, but other, less-clear names such as “fresh scent,” “powder fresh,” and “sport fresh” are also used, so it's important to smell before you buy. These fragrances may irritate some patients’ skin. However, an antiperspirant that's labeled as “fragrance free” can still contain ingredients to which a patient may be sensitive, so it's best to check the label for common chemical irritants. Numerous products that don't contain the active aluminum and/or zirconium compounds are available, and some say they can prevent perspiration as well as odor. Because these products are considered cosmetics, they're not regulated by FDA and thus their effectiveness hasn't been independently verified. Speculation that the use of antiperspirants is associated with an increased risk of breast cancer continues to circulate. However, the American Cancer Society (ACS) and FDA have both concluded there is no credible scientific/medical evidence linking the use of antiperspirants to breast cancer. There has also been some concern about the use of parabens in antiperspirants because of their weak estrogen-like properties. However, according to the ACS, clinical studies have not shown any direct link between parabens and any health problems, and FDA has indicated that most major brands of antiperspirants and deodorants do not contain parabens. Those that do can easily be identified by reading the label.

Detection of Diethylene Glycol in Glycerin and Propylene Glycol by using high performance thin layer chromatography HPTLC

We were developed analytical method rapid, sensitive and easy to use to detect Diethylene glycol (DEG) in some of excipients: Glycerin, and propylene glycol by using high-performance thin-layer chromatography HPTLC with plate fluorinated: HPTLC Plate silica gel 60 F 254, and with mobile phase: acetone: toluene: 5 M ammonium hydroxide at rates 85: 5:10, respectively. And Use a scanner with wavelength: 325 nm. This method allows the detection and assay of toxic Diethylene glycol in excipients: glycerin and propylene glycol in concentrations of not less than 0.1%. This method was verified the validity of it to conduct all the constitutional requirements.

Cryoinjury in endothelial cell monolayers

Developing successful cryopreservation strategies for corneas have proven to be more difficult than anticipated, because of the resulting loss of viability and detachment of endothelial cells from Descemet’s membrane following cryopreservation of corneas. The objectives of this study are to develop a more detailed understanding of cryoinjury in human corneal endothelial cell (HCEC) monolayers and to examine the effects of storage temperature, cryoprotectant type and concentration, and cooling/warming rates on HCEC monolayers. Monolayers of endothelial cells attached to collagen-coated glass, immersed in an experimental solution (with and without cryoprotectant) were cooled at 1 °C/min to various temperatures (−5 to −40 °C), then thawed directly or cooled rapidly to −196 or to −80 °C before thawing. Cryoprotectants used were dimethyl sulfoxide and propylene glycol in concentrations of 1 and 2 M. Monolayers were assessed for membrane integrity and detachment using SYTO/ethidium bromide fluorescent stain. The presence of cryoprotectants resulted in high recovery of membrane integrity and low monolayer detachment in monolayers thawed directly from temperatures down to −40 °C. In contrast, there was excessive detachment and loss of membrane integrity in monolayers cooled to −196 °C compared to monolayers cooled to −80 °C. Also, increasing cryoprotectant concentrations did not improve recovery of the monolayers. The higher recovery and lower detachment after storage at −80 °C compared to storage at −196 °C suggest that storage temperatures for corneas should be re-evaluated.

Propylene glycol-induced cholesteatoma in chinchilla middle ears

Propylene glycol is a solvent commonly used in topical otic preparations. This study examines the occurrence of inflammatory changes and cholesteatoma in chinchilla middle ears after the application of propylene glycol in varying concentrations. A total of 32 ears were studied, divided into four treatment groups. Three groups received propylene glycol in concentrations of 10%, 50%, and 90%. One group received normal saline. Six weeks after the application of propylene glycol to the middle ear through the bulla, examination revealed cholesteatoma, tympanic membrane perforations, and middle ear adhesions in most of the ears subjected to 50% and 90% propylene glycol. Only one ear treated with 10% propylene glycol showed a cholesteatoma, while the group treated with normal saline showed only mild inflammation. Histologic preparations confirmed cholesteatoma and revealed replacement of the normal columnar epithelium by keratinizing stratified squamous epithelium, inflammatory infiltration, and granulation tissue eroding underlying bone. We conclude that exposure to propylene glycol in high concentrations will consistently produce cholesteatoma in chinchilla middle ears. Although the effects of propylene glycol in the human middle ear are yet to be investigated, we recommend the avoidance of otic preparations containing high concentrations of propylene glycol in patients with tympanic membrane perforations.

Propylene Glycol Aerosolization and the Diagnosis of Pulmonary Histoplasmosis

It has been established that propylene glycol aerosolization to induce sputum from patients with unproductive cough has diagnostic value in cytologic examinations and for culture of acid-fast bacilli. In contrast, propylene glycol in concentrations found in sputum induced by aerosolization appears to interfere with yeast-to-mycelial phase dimorphism of Histoplasma capsulatum. Usual diagnostic cultural procedures rely upon conversion of the tissue phase (yeast phase) to the saprophytic phase (mycelial phase). It would appear, therefore, that induction of sputum for cultural procedures in the diagnosis of pulmonary histoplasmosis by the use of propylene glycol aerosol may significantly handicap laboratory confirmation.