>> Glucosamine Sulfate
1. Evaluation of the physicochemical stability and skin permeation of glucosamine sulfate.
Kanwischer M, Kim SY, Kim JS, Bian S, Kwon KA, Kim DD. Department of Biotechnology, Dongseo University, Busan, South Korea.Drug Dev Ind Pharm. 2005 Jan;31(1):91-7.
"Glucosamine sulfate (GS) is known to stop the degenerative process of osteoarthritis. Because most of the GS formulation on the market is in the oral form, an alternative formulation such as a transdermal delivery system (TDS) is necessary in order to increase patient compliance. As the initial step to develop a TDS of GS, the physicochemical stability and permeation study in rat skin were examined. Evaluation of the stability of GS at different pHs showed the compound to be most stable at pH 5.0. The degradation rate constant at 25 degrees C was estimated to be 5.93 x 10(-6) hr(-1) (t90 approximately 2.03 years) in a pH 5 buffer solution. Due to its hydrophilic characteristic, low skin permeability was expected of GS. However, the skin permeation rate was determined to be 13.27 microg/cm2/hr at 5% concentration. Results of this study suggest the possibility of developing GS into a transdermal delivery system."
2. Which Common Skin Care Ingredients and Cosmetic Procedures Do More Harm Than Good?
DermCareMD, Tuesday, July 10, 2007.
"Hydroquinone is used as a cosmetic skin-bleaching agent, but in some countries it is banned (in The Netherlands, for example, where it was banned in 2001 because it can cause white patches on the face (leukoderma) with confetti-like depigmentation and subcutaneous (below the surface of the skin) dark collections of pigment (exogenous ochonosis). .. The safest and most effective ingredients for skin lightening are Magnesium Ascorbyl Phosphate (vitamin C), Glycyrrhiza Glabra (Licorice) Extract, Niacinamide (Vitamin B3), Rumex Occidentalis Extract (Tyrostat®*), Retinol (a safe and non irritating form of vitamin A), Glucosamine Sulfate and Ursolic Acid."
3. Skin lightening compositions and methods.
Ratan K. Chaudhuri (Lincoln Park, NJ, US). Publication date: 12/11/2008.
"Suitable skin lightening agents also include the sugar amines, which are also known as amino sugars and are to be employed in a safe and effective amount. The sugar amine compounds useful in the present invention are described U.S. Pat. No. 6,159,485. Sugar amines can be synthetic or natural in origin and can be used as pure compounds or mixtures of compounds (e.g., extracts from natural sources or mixtures of synthetic materials). Glucosamine is generally found in many shellfish and can also be derived from fungal sources. As used herein, "sugar anmine" includes isomers and tautomers of such and its salts (e.g., HCl salt) and is commercially available from Sigma Chemical Co. Examples of sugar amines that are useful herein include glucosamine, N-acetyl glucosamine, glucosamine sulfate, mannosamine, N-acetyl mannosamine, galactosamine, N-acetyl galactosamine, their isomers (e.g., stereoisomers), and their salts (e.g., HCl salt). Preferred ingredients are glucosamine, particularly D-glucosamine and N-acetyl glucosamine, particularly N-acetyl-D-glucosamine. Yet another group of skin lightening agents are the N-acyl amino acid compounds, including, but are not limited to, N-acyl phenylalanine, N-acyl tyrosine, their isomers, including their D and L isomers, salts, derivatives, and mixtures thereof. An example of a suitable N-acyl amino acid is N-undecylenoyl-L-phenylalanine is commercially available under the tradename Sepiwhite® from Seppic (France)."