hydroquinone solubility in glycerin hydroquinone solubility in glycerin

Anyone you share the following link with will be able to read this content: Sorry, a shareable link is not currently available for this article. 0000002221 00000 n Retinoids, in particular retinoic acid, retinal, and their derivatives, isomers and analogs (such as adapalene, tazarotene and isotretoin), are beneficial for improving rough skin texture, mottled pigmentation, sallow complexion, lines and wrinkles. Skin Contact Wash off immediately with plenty of water for at least 15 minutes. Hydrogen peroxide is used and the reaction gives a mixture of hydroquinone and catechol: An accessible route involves the reaction of sodium hydroxide with 1,4-dichlorobenzene. NR 1L~tyj|ZZ3]jFlszH#bd]="nVj =rBF-=Y?Pe 3(\[3;wR-+7Fn ~pSQ(Rpiw^zYr''t@\vobE]u'C}io0q;^k5C@|zZNNA>,XOrztV;qO*w:MC$OI\_$Io 'v [ J. Pharm. Discoloration of hydroquinone compositions may be accelerated by repeated exposure to oxygen or exposing the compositions to high temperatures, which may be found inside a car or delivery vehicle on a hot sunny day. The preferred protected retinoid is in the form of small beads or vesicles which are of a form that can be adjusted to be incorporated into varied topical compositions. Thus, merely adding one retinoid to a hydroquinone composition would result in instability and/or discoloration, and adding hydroquinone to a retinoid product would have a similar result. Eng. 420, 2429 (2016), W. E. Acree Jr, Thermochim Acta 189, 3756 (1991), F. L. Nordstrm, . C. Rasmuson, J. Chem. Hydroquinone is soluble in alcohol solvents such as ethanol and methanol [17]. It is found in wheat, rye, and barley.It is a precursor to diverse industrial products including polymers and plasticizers, as well as being a component of a number of hair and skin conditioners. 0000002198 00000 n At 40C, 4% hydroquinone compositions are more likely to excessively discolor and magnesium ascorbyl phosphate helps to stabilize the color, by preventing the brownish black discoloration and maintaining an amber color. trailer << /Size 393 /Info 347 0 R /Root 375 0 R /Prev 573815 /ID[<6893db2526a970a0c364cca2e99ca522>] >> startxref 0 %%EOF 375 0 obj << /Type /Catalog /Pages 346 0 R /Metadata 348 0 R >> endobj 391 0 obj << /S 2217 /Filter /FlateDecode /Length 392 0 R >> stream LSPS, Laboratoire de Spectrochimie Et Pharmacologie Structurale, University of Tlemcen, BP 119, 13000, Tlemcen, Algeria, Department of Biology, University of Ghardaia, BP 455, 47000, Ghardaia, Algeria, You can also search for this author in This range of pH has been preferred for hydroquinone compositions, because it has been believed that the hydroquinone is less likely to excessively discolor under acid conditions. 1 Solubility data for compounds that ordinarily are liquids at 25 are expressed in terms of the ratio of the volume of solute to the volume of solvent; i.e., 1 mL dissolved in mL of solvent. Monobenzone is the monobenzyl ether of hydroquinone used medically for depigmentation. International Journal of Thermophysics 2008-2023 ChemPoint. 338, 217223 (2013), S. H. Ali, F. S. Al-Mutairi, M. A. Fahim, Fluid Phase Equilib. Using a laser-monitoring observation technique, the solubility of hydroquinone in water, methanol, ethanol, 2-propanol, ethyl acetate, butyl acetate, and acetic acid were measured at temperatures ranging from 276.65 K to 345.10 K under the atmospheric pressure. The present invention addresses the problem of excessive discoloration in hydroquinone compositions of a neutral pH. Antioxidants, preferably sulfites, including but not limited to sulfites, bisulfites, metabisulfites, their salts, and their derivatives, most preferably sodium metabisulfite, have been used to stabilize certain compositions, which have included hydroquinone. valproic acid having a carboxyl group bound to a chain of seven or more carbon atoms, e.g. 88, 161164 (2010), J. Delgado, Int. Toxicol. [Na+].OC(=O)CN(CC([O-])=O)CCN(CC(O)=O)CC([O-])=O, trimethyl-[phenyl-bis(trimethylsilyloxy)silyl]oxysilane, C[Si](C)(C)O[Si](O[Si](C)(C)C)(O[Si](C)(C)C)C1=CC=CC=C1, C\C(=C/C=O)\C=C\C=C(\C=C\C1=C(CCCC1(C)C)C)/C, 1-hexadecanoyl-2-(9Z,12Z-octadecadienoyl)-sn-glycero-3-phosphocholine, CCCCCCCCCCCCCCCC(=O)OC[C@H](COP([O-])(=O)OCC[N+](C)(C)C)OC(=O)CCCCCCC\C=C/C\C=C/CCCCC, 2-[2-[2-[2-[2-[2-(2-dodecoxyethoxy)ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethanol, C[Si]1(C)O[Si](C)(C)O[Si](C)(C)O[Si](C)(C)O[Si](C)(C)O1, O=C1C(=O)C(C2=CNC3=C(C(C(=O)C4=C32)=O)C)=C2C4=CNC2=C1C, [Na+].[Na+].[Na+]. HYdroquinone can be found in various skin care products. Then take the water and put the measurement into the microwave until boiled. An acceptable carrier also possesses suitable aesthetic and cosmetic qualities and may include emollients, conditioners and the like. Tests, which results are detailed in the following two tables, are performed to show how well sodium metabisulfite ("SMBS") stabilizes color at each pH at 5C and 40C in 4% hydroquinone ("HQ") compositions. [33], Hydroquinone has been shown to be one of the chemical constituents of the natural product propolis. [23] This conclusion was reached based on the extent of absorption in humans and the incidence of neoplasms in rats in several studies where adult rats were found to have increased rates of tumours, including thyroid follicular cell hyperplasias, anisokaryosis (variation in nuclei sizes), mononuclear cell leukemia, hepatocellular adenomas and renal tubule cell adenomas. Methylaminophenol, used in photography, is produced in this way:[8]. AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR, Kind code of ref document: Found. Consistent with a condensation reaction, water was determined to be the primary byproduct. One embodiment of the invention is a composition which comprises hydroquinone (about 1% to about 12%, preferably about 2% to about 10%, more preferably about 2% to about 8%, more preferably with about 2% to about 4%, and most preferably about 3% to about 4%) and has a neutral pH of from about 5.5 to about 8.0, more preferably a pH of from about 5.5 to about 7.5, and most preferably at a pH of from about 6.0 to about 7.5. Data 53, 199200 (2008), N. Sunsandee, S. Suren, N. Leepipatpiboon, M. Hronec, U. Pancharoen, Fluid Phase Equilib. These can be burning, redness, sensitization and irritation in some patients. Conversion factors (at 25C and normal atmospheric pressure) 1 ppm = 4.5 mg/m 3 1 mg/m 3 = 0.222 ppm Table 1. [Na+].OC(=O)CC(O)(CC([O-])=O)C(O)=O.OC(=O)CC(O)(CC([O-])=O)C(O)=O, SPECIFIC USE OF COSMETICS OR SIMILAR TOILET PREPARATIONS, Preparations for care of the skin for chemically bleaching or whitening the skin, PREPARATIONS FOR MEDICAL, DENTAL, OR TOILET PURPOSES, Medicinal preparations containing organic active ingredients, Acids; Anhydrides, halides or salts thereof, e.g. On this Wikipedia the language links are at the top of the page across from the article title. It is a reducing agent that is reversibly oxidized to semiquinone and quinone. The combined nearly ideal binary solvent (NIBS)-Redlich-Kister equation is . The obtained results show that the solubility of benzoic acid in water is greater than that of salicylic acid, but in the case of the two isomers of dihydroxybenzene, the solubility of resorcinol is approximately 100 times that of hydroquinone. D7VJV//KZ&t}JSW/L@,l@^ D@ @8 i W `^;V rD}25p>.Bv1}\_E p9 endstream endobj 392 0 obj 1303 endobj 376 0 obj << /Type /Page /Parent 350 0 R /Resources 377 0 R /Contents 381 0 R /MediaBox [ 0 0 595 842 ] /CropBox [ 0 0 595 842 ] /Rotate 0 >> endobj 377 0 obj << /ProcSet [ /PDF /Text ] /Font << /TT2 379 0 R /TT4 383 0 R /TT6 385 0 R >> /ExtGState << /GS1 387 0 R >> /ColorSpace << /Cs6 378 0 R >> >> endobj 378 0 obj [ /ICCBased 386 0 R ] endobj 379 0 obj << /Type /Font /Subtype /TrueType /FirstChar 32 /LastChar 252 /Widths [ 250 0 408 500 0 833 778 180 333 333 500 564 250 333 250 278 500 500 500 500 500 500 500 500 500 500 278 278 564 564 564 444 921 722 667 667 722 611 556 722 722 333 389 722 611 889 722 722 556 722 667 556 611 722 722 944 722 722 611 333 0 333 0 500 0 444 500 444 500 444 333 500 500 278 278 500 278 778 500 500 500 500 333 389 278 500 500 722 500 500 444 0 0 0 541 0 0 0 0 0 0 0 500 0 0 0 0 0 0 0 0 0 0 0 333 0 0 0 500 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 400 0 0 0 0 576 0 0 0 0 0 0 0 750 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 722 0 0 0 0 0 722 0 0 500 444 0 0 0 444 0 0 0 444 444 0 0 0 0 0 0 0 0 0 0 500 0 500 0 0 0 0 0 500 ] /Encoding /WinAnsiEncoding /BaseFont /BCGIOE+TimesNewRoman /FontDescriptor 380 0 R >> endobj 380 0 obj << /Type /FontDescriptor /Ascent 891 /CapHeight 656 /Descent -216 /Flags 34 /FontBBox [ -568 -307 2028 1007 ] /FontName /BCGIOE+TimesNewRoman /ItalicAngle 0 /StemV 94 /XHeight 0 /FontFile2 388 0 R >> endobj 381 0 obj << /Length 462 /Filter /FlateDecode >> stream In 1-octanol, the decreasing order of the solubility of these compounds is as follows: resorcinol>benzoic acid>salicylic acid>hydroquinone. 0000003430 00000 n The experimental solubilities were correlated using two regression equations. 2017-02-16T10:10:56+01:00 Hydroquinone occurs in the environment as a result of anthropogenic processes, as well as in natural products from plants and animals. This page was last modified on 19 June 2019, at 20:05. 65, 5786 (1998), Y.-H. Zhang, Trends Analyt. 108. This composition is color stabilized and cosmetically elegant. Acta 423, 137144 (2000), S.-T. Lin, S. I. Sandler, Ind. uv curable cellulose estersuv curable cellulose esters . . It is also used to prepare 2% bleaching creams and certain intermediates for the synthesis of dyes, and it has some activity as an antitumoragent. 2023 Springer Nature Switzerland AG. Treatment with hydroquinone interferes with the action of tyrosinase, which is an enzyme used in the synthesis of melanin, and compositions are sold across the counter at about 2% hydroquinone and by prescription at higher concentrations. This chamber is lined with cells that secrete catalases and peroxidases. Chemically, hydroquinone is designated as p-dihydroxybenzene; the empirical formula is C 6 H 6 O 2; molecular weight is 110.0. Compositions according to this invention may include dermatologically acceptable carriers. PubMedGoogle Scholar. 2005 Wiley-VCH, Weinheim. vitamin C; Salts thereof, Medicinal preparations containing active ingredients not provided for in groups A61K31/00-A61K41/00, Mixtures of active ingredients without chemical characterisation, e.g. Remove contact lenses, if present and easy to do. 38, 565571 (2006), K. Carlsson, B. Karlberg, Anal. Methods and products for nucleic acid production and delivery, Nucleic acid product and its administration method, Nucleic acid product and method of administration thereof, Compositions and systems for the treatment of hyperpigmentation, Methods for prevention of post-inflammatory hyperpigmentation, Skin care compositions containing retinoids, Improved method for stability of ageing comprising thirosinase inhibitor activity, Use of ascorbic acid to reduce irritation of topically applied active ingredients, COSMETIC COMPOSITIONS WITH ANTIMICOTIC PROPERTIES, EFFECTIVE AGAINST PSORIASIS AND HAIR LOSS AND COSMETIC METHOD FOR, Treatment or prevention of undesired skin pigmentation, Skin care compositions and method of improving skin appearance, Ultrasound enhancement of percutaneous drug absorption, Skin whiteners containing hydroxytetronic acid, Stabilized retinoid-containing skin care compositions, Retinoid compositions containing a water soluble antioxidant and a chelator, Composition and method for treating rosacea and sensitive skin with free radical scavengers, Skin care compositions containing imidazoles and retinoids, Stable compositions containing a retinoid and an enzyme based antioxidant system, Self-tanning compositions containing dha and propolis extract, Composition and process for stabilizing oxygen-unstable species, Bleaching preparation and cosmetic for preventing and improving aging of skin, Composition and method for the treatment of pigmentation disorders, Composition for cosmetic or pharmaceutical use, Remedies for pigmentation and melanocyte proliferation inhibitors, Public reference made under article 153(3) epc to a published international application that has entered the european phase, Divisional application: reference to earlier application, Information on the status of an ep patent application or granted ep patent. A further embodiment of the invention includes a method for stabilizing a hydroquinone composition (with about 1% to about 12% hydroquinone, preferably about 2% to about 10%, more preferably about 2% to about 8%, and most preferably about 3% to about 4%) with a neutral pH of from about 5.5 to about 8.0, more preferably a pH of from about 5.5 to about 7.5, and most preferably at a pH of from about 6.0 to about 7.5, by adding a water-soluble antioxidant, preferably sulfite, including but not limited to sulfites, bisulfites, metabisulfites, their salts and their derivatives, most preferably sodium metabisulfite, and a cationic salt of acidic ascorbyl esters, preferably sodium ascorbyl phosphate, more preferably aminopropyl ascorbyl phosphate, most preferably magnesium ascorbyl phosphate. Hydroquinone is combustible when preheated. The Density of hydroquinone is . I understand the concentrations are high but I have used them before, its just too expensive to keep buying from a compounding pharmacy. 2 Liquid phase only; silicon dioxide remains as a residue in these solvents. Classical photo shops also sell hydroquinone. Hydroquinone is a white, odorless, crystalline solid with an extremely low vapor pressure. HyTSwoc [5laQIBHADED2mtFOE.c}088GNg9w '0 Jb Read our Privacy Notice. Diamines, useful in the rubber industry as antiozone agents, are similarly produced from aniline: Hydroquinone has a variety of uses principally associated with its action as a reducing agent that is soluble in water. The present invention combats this problem, with hydroquinone compositions in the neutral pH range, preferably a pH of from about 5.5 to about 8.0, more preferably a pH of from about 5.5 to about 7.5, and most preferably at a pH of from about 6.0 to about 7.5. endstream endobj 276 0 obj <>stream Gravimetric method is used to measured hydroquinone solubility in water, ethanol and in water+ethanol binary mixtures at temperatures (293.15, 295.15, 298.15, 300.15, 303.15, 305.15, 308.15, 310.15 and 313.15)K. Mole fractions solubility of hydroquinone are correlated with temperature by using the Apelblat equation. Tests, which results are detailed in the following two tables, are performed at 5C and 40C for certain percentages of magnesium ascorbyl phosphate at specific pHs. The preferred form of protected retinol is manufactured by SunSmart (also known as Particle Sciences, Inc. of Bethlehem, PA) under the brand name of SunCaps A-1283. The composition is preferably formulated in separate phases as designated below. hydroquinone, 1,4-benzenediol, quinol, 1,4-dihydroxybenzene, p-benzenediol, 4-hydroxyphenol, p-hydroquinone, p-hydroxyphenol, p-dihydroxybenzene, benzoquinol, Electrophoresis, Western Blotting and ELISA, Chromatography and Mass Spectrometry Reagents, Laboratory Syringe Needles and Accessories, Lab Coats, Aprons, and Other Safety Apparel, Sharps Disposal Containers and Accessories, Classroom Laboratory Supplies and Consumables, Applied Biosystems TaqMan Assay and Arrays Search Tool, Applied Biosystems TaqMan Custom Assay Design Tools, Applied Biosystems Custom qPCR Primers and TaqMan Probes Tool, Chemical Storage and Management Resource Center, Solubility in water: 70g/L in water (20C). Hydroquinone is extensively used as a photographic developer, an antioxidant, and a stabilizing agent for readily oxidizable polymers. 0000005757 00000 n Cationic salts of acidic ascorbyl esters, including inorganic salts, preferably magnesium ascorbyl phosphate, and amino acyl derivatives, preferably aminopropyl ascorbyl phosphate, are preferred in this invention. Then add it to the ingredients. Retinoid compositions, in particular retinoic acid, retinal, and their derivatives, isomers and analogs (such as adapalene, tazarotene and isotretoin) are known to be effective in improving rough skin texture, mottled pigmentation, sallow complexion, lines and wrinkles. Chim. HVoLg~Z+ Airborne hydroquinone may be oxidized to quinone at ordinary . HMkA+"c>jZ^ho=81NW;]Ib;+i#iFArHpz). `9F6~qg3]0,#!V9Q> p=|h| Exceptional antioxidant qualities are seen at 0.10% (all percentages in the application are weight percent) and above, preferably from about 0.05% to about 0.5% for sodium metabisulfite. %PDF-1.4 % By accepting all cookies, you agree to our use of cookies to deliver and maintain our services and site, improve the quality of Reddit, personalize Reddit content and advertising, and measure the effectiveness of advertising. By clicking Accept, you consent to the use of cookies. Recent pieces of . There are various other uses associated with its reducing power. x- [ 0}y)7ta>jT7@t`q2&6ZL?_yxg)zLU*uSkSeO4?c. R -25 S>Vd`rn~Y&+`;A4 A9 =-tl`;~p Gp| [`L` "AYA+Cb(R, *T2B- HYPERPIGMENTARY STAIN ELIMINATING CREAM FOR FACE SKIN AND ITS USE. Monobenzone occurs as a white, almost tasteless crystalline powder, soluble in alcohol and practically insoluble in water. I would like to add retinol and kojic acid to it as well. Eng. 12.4. 57, 295300 (2013), R. F. Pires, M. R. Franco Jr, Fluid Phase Equilib. ORIGINAL CODE: 0009012, Free format text: One of these, 4-butylresorcinol, has been proven to be more effective at treating melanin-related skin disorders by a wide margin, as well as safe enough to be made available over the counter. Boucif Belhachemi. Cookie Notice antiphlogistics and cardiaca, Cosmetics or similar toilet preparations characterised by the composition, Cosmetics or similar toilet preparations characterised by the composition containing inorganic ingredients, Sulfur; Selenium; Tellurium; Compounds thereof, Cosmetics or similar toilet preparations characterised by the composition containing organic compounds, Cosmetics or similar toilet preparations characterised by the composition containing organic compounds containing oxygen, . ~lgM~Gc{1S_1Q/_/v">S 9 However, hydroquinone discolors at the pH range of 7.0 to 8.5. The aquatic toxicity of hydroquinone to fresh water fish, Daphnia, and algae was between 0.050- . Your document download will begin shortly. Calorim. [Na+].OC[C@H](O)[C@H]1OC([O-])=C(OP([O-])([O-])=O)C1=O, N1=CC(C(=O)OCC)=CC=C1C#CC1=CC=C(SCCC2(C)C)C2=C1, C1=C(C(O)=O)C=CC2=CC(C3=CC=C(C(=C3)C34CC5CC(CC(C5)C3)C4)OC)=CC=C21, CC(=O)OC1=C(C)C(C)=C2O[C@@](CCC[C@H](C)CCC[C@H](C)CCCC(C)C)(C)CCC2=C1C, disodium;2-[2-[carboxylatomethyl(carboxymethyl)amino]ethyl-(carboxymethyl)amino]acetate, [Na+]. Eng. We have discovered that a hydroquinone composition (with about 1 to about 12% hydroquinone, preferably with about 2% to about 10%, more preferably with about 2% to about 8%, more preferably with about 2% to about 4%, most preferably with about 3% to about 4% hydroquinone) with preferably a pH of from about 5.5 to about 8.0, more preferably a pH of from about 5.5 to about 7.5, and most preferably at a pH of from about 6.0 to about 7.5, can include cationic salts of acidic ascorbyl esters, preferably sodium ascorbyl phosphate, more preferably aminopropyl ascorbyl phosphate, most preferably magnesium ascorbyl phosphate as an antioxidant and the color destabilization problems are appreciably less as compared to hydroquinone compositions without such a cationic salt of acidic ascorbyl esters in the neutral pH range: preferably a pH of from about 5.5 to about 8.0, more preferably a pH of from about 5.5 to about 7.5, and most preferably at a pH of from about 6.0 to about 7.5. 20, 14331442 (1986), G. Wienke, J. Gmehling, Toxicol. Production of Hydroquinone Industrial production of hydroquinone usually happens in two ways. It has a white-solid appearance. Additionally, a water-soluble antioxidant, preferably a sulfite, including but not limited to sulfites, bisulfites, metabisulfites, their salts and their derivatives, most preferably sodium metabisulfite, may be helpful in stabilizing the hydroquinone composition. Part of Springer Nature. For a shipping quote, check the box and the bottom and provide us your shipping information. Although about 0.01% sodium metabisulfite without magnesium ascorbyl phosphate may not color stabilize an about 4% hydroquinone composition, and about 0.5% magnesium ascorbyl phosphate without sodium metabisulfite may not either, the combination of sodium metabisulfite and magnesium ascorbyl phosphate in these percentages is effective to stabilize the color of the about 1% to about 12%, about 2% to about 10%, preferably about 2% to about 8% and more preferably about 3% to about 4% and most preferably 4% hydroquinone composition. Hydroquinone is sold by chemical suppliers. However, these hydroquinone-containing compositions were in the acidic pH range and did not contain cationic salts of acidic ascorbyl esters, such as magnesium ascorbyl phosphate. Hydroquinone occurs as fine, white needles. This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions. [32], Hydroquinone is thought to be the active toxin in Agaricus hondensis mushrooms. The obtained results show that the . Then take the water and put the measurement into the microwave until boiled. The most preferred example of such an antioxidant is sodium metabisulfite. Color stability improvement is evident at all levels. Solubility: Moderately soluble in water, glycerin, propylene glycol, and highly soluble in ethanol Features & Benefits Can work in conjunction with glycolic acid to help reduce pigment in melasma Non-GMO Extremely low vapor pressure USP Grade European Pharma Grade Drug master file available upon request Applications It is soluble in water. The present invention is not to be limited by any mechanism described in the specification, because it is defined by the claims. The solubilities in binary and ternary systems of hydroquinone (1,4-dihydroxybenzene) and p-quinone (1,4-benzoquinone) in supercritical carbon dioxide were measured in the pressure range 10.0 to 35.0 MPa at temperatures of 333, 348 and 363 K.In binary systems, the solubility of hydroquinone was three orders of magnitude lower than that of p-quinone. Preferably, the protected retinoid, in particular retinoic acid, retinal, and their derivatives, isomers and analogs (such as adapalene, tazarotene and isotretoin), is in the form of small beads or spheres suitable for incorporation into a topical composition. Also in this embodiment is a cationic salt of acidic ascorbyl esters, which further helps to maintain the acceptable color desired in the hydroquinone composition. The color stability of the hydroquinone composition is promoted by one or more antioxidants in the hydroquinone phase, preferably sulfite, including but not limited to sulfites, bisulfites, metabisulfites, their salts and their derivatives, most preferably sodium metabisulfite, and a cationic salt of acidic ascorbyl esters, most preferably magnesium ascorbyl phosphate. ChemPoint will not under any circumstances release personal user information to individuals or companies. As a polymerisation inhibitor, exploiting its antioxidant properties, hydroquinone prevents polymerization of acrylic acid, methyl methacrylate, cyanoacrylate, and other monomers that are susceptible to radical-initiated polymerization. They may also include ingredients with other therapeutic actions, such as anti-inflammatories, antibiotics, exfoliants and peels. Hydroquinone undergoes oxidation under mild conditions to give benzoquinone, process which is reversible. Dietland Muller-Schwarze, 2003, page 43 (, National Institute for Occupational Safety and Health, Additive manufacturing of ceramics from preceramic polymers, http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:31976L0768:EN:HTML, "Clear N Smooth Skin Toning Cream recalled", Skin Bleaching Drug Products for Over-the-Counter Product Use; Proposed Rule, "About the Center for Drug Evaluation and Research - Hydroquinone Studies Under The National Toxicology Program (NTP)", Campaign For Safe Cosmetics - Hydroquinone, "Skin lightening preparations and the hydroquinone controversy", https://en.wikipedia.org/w/index.php?title=Hydroquinone&oldid=1136453324, Wikipedia articles needing page number citations from October 2016, Pages using collapsible list with both background and text-align in titlestyle, Articles containing unverified chemical infoboxes, Creative Commons Attribution-ShareAlike License 3.0, The most widely used route is similar to the, A potentially significant synthesis of hydroquinone from, Hydroquinone was first obtained in 1820 by the French chemists, Pelletier and Caventou (1820) "Recherches chimiques sur les quinquinas" (Chemical investigations of quinquinas [i.e., the bark of various, This page was last edited on 30 January 2023, at 11:09.