Disclosed are methods of synthesis and/or purification of certain 3,7-diamino-phenothiazin-5-ium compounds (diaminophenothiazinium compounds) including Methylthioninium Chloride (MTC) (Methylene Blue), and the resulting high purity characterized by a purity greater than 98%, and very low levels of heavy metals and organic impurities Azure A, B, C and MVB. Also disclosed are methods of treatment of a tauopathy or methemoglobinemia in a patient in need thereof, comprising administering to the patient a therapeutically effective amount of the high-purity diaminophenothiazinium compound.

A method of separating oil-soluble pigment and water-soluble pigment from natural material using aerogels characterized in comprising the steps of: (A) immersing a natural material in a leaching solvent to extract a pigment; (B) mixing the leaching solution from which pigment is extracted in step (A) with aerogel to adsorb oil-soluble pigment to aerogels; (C) separating oil-soluble pigment adsorbed on the surface of aerogel in step (B); (D) drying and concentrating the pigment separated in step (C), enhancing a method of separating from natural material the initial substance for pharmaceuticals, food, cosmetics, etc. facilitating a safer and more efficient production process compared to the conventional separation method.

The present disclosure provides colorant compounds and methods of isolation of the colorant compounds derived from a reaction of genipin and an amine. The colorant compositions comprise purified compounds (e.g., a purified polymer or a purified dimer) obtained from multiple fractioning by chromatography of the reaction resulting material. The purified polymer or dimer can be used as a colorant by itself or in combination with another colorant for imparting color to a food, a drug, a cosmetic, a medical device, and textile products.

The present invention provides a method of manufacturing a reactive composition: (a) dissolving 2-[(4-aminophenyl)sulfonyl]ethanesulfonic acid in water to form a solution; (b) introducing excess nitrite or excess nitrous acid and the solution into an acid solution to form a diazonium salt; (c) adding 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid to react with the diazonium salt; (d) adding 7-acetamido-4-hydroxy-2-naphthalenesulfonic acid to react with the diazonium salt; (e) adding a first alkaline substance to adjust a pH value; (f) adding a second alkaline substance to adjust the pH value; (g) adding a third alkaline substance to control the pH value; (h) adding an acidic substance to adjust the pH value; and (i) adding an additive agent to obtain the reactive composition, wherein the additive agent is acetic acid, sodium hydroxide, acetate, sulfonic acid buffering agent, or a combination thereof.

A method of solubilizing a composition, such as an organic manufactured photochromic dye that is free of carcinogens, non-mutagenic, non-toxic to human skin in any concentration, and suitable for application to, and absorbable by, human skin. The photochromic dye is suitable to be applied directly to human skin, and which dye is configured to indicate exposure to UV rays. The composition is configured to change color upon exposure to UVA, UVB and/or UVC rays. The composition can be used with other compositions, such as sunscreen, and be applied to human skin prior to application of the sunscreen, or, formulated with the sunscreen such that when the active ingredients of the sunscreen diminish, the photochromic dye will change color to generate a visual indicator of this condition.

The invention relates to a process of creating particles of controlled size by creating them in the interstitial regions in a continuous liquid phase that contains a second, inert gas phase at high volume fraction; namely a foam. The second phase creates a physical barrier that limits the aggregation of formed particles beyond the size of the narrow interstitial regions occupied by the continuous phase. This technique is useful when the particles normally create large aggregates due to the fast nature of the reaction and the strong attractions between the formed particles, and for enhancing the deposition of high-value materials by connecting them to coacervates of controlled size.

Provided are a quinacridone pigment having a low content of a primary aromatic amine, a method for producing the same, and also a gravure and flexo ink, a colorant for plastic, a paint, a lithographic ink, a toner, or an ink-jet ink using the pigment. The quinacridone pigment having a low primary aromatic amine content is provided by washing a quinacridone pigment with at least one solvent selected from water and an organic solvent, or by adding an oxidizing agent to a pigment slurry including a quinacridone pigment and at least one solvent selected from water and an organic solvent to oxidatively decompose the aromatic amine.

The present disclosure provides colorant compounds and methods of isolation of the colorant compounds derived from a reaction of genipin and an amine. The colorant compositions comprise purified compounds (e.g., a purified polymer or a purified dimer) obtained from multiple fractioning by chromatography of the reaction resulting material. The purified polymer or dimer can be used as a colorant by itself or in combination with another colorant for imparting color to a food, a drug, a cosmetic, a medical device, and textile products.

The present invention is directed towards natural colorants comprising a material selected from the group consisting of genipin, purified genipin, pre-genipin compounds, iridoid compounds, genipin deriviatives, a genipin-containing substance, and combinations of any thereof; and a primary amine containing compound. Processes of making natural colorants are further disclosed. Additionally, processes of producing a desired color of natural colorants are disclosed.

A method for preparing a colorant for use in an ink composition including a substantially non-aqueous carrier composition includes providing a chromophore precursor including one or multiple functional groups which may be subjected to a chemical reaction to form a salt with a preselected counter ion; providing a salt including the preselected counter ion; and providing an organic solvent that is not miscible with water and wherein the reaction product of the chromophore precursor and the salt including the preselected counter ion is soluble; preparing a chromophore precursor solution in water by dissolving a quantity of the chromophore precursor in water adding a quantity of the organic solvent while stirring; adding the salt including the preselected counter ion while stirring to form a resalted chromophore; separating the resalted chromophore from the reaction mixture. The addition of the salt including the preselected counter ion is performed until a molar excess of counter ion has been added with respect to the molar amount of functional groups comprised in the chromophore precursor; A colorant is obtainable and an ink composition includes such a colorant.