Hydroquinone cream

Charge linoleic acid, safflower oil, jojoba oil, petrolatum, behenyl erucate, and cetyl alcohol and heat to 70°C. 

Add tocopherol to above just before adding the rest of the ingredients (see below). 

Heat item 15 to 70°C and add and dissolve item 18. Add and disperse item 16. 

In a separate vessel, add item 1 and BHA and heat to 45°C dissolve items 5, 7, and 8, and heat to 45°C. Add sodium bisulfite. Stir to dissolve. 

Add step 2 to step 1 in a homogenizer, and then during homogenization add step 4 and also add tocopherol. Homogenize well. 

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Gladstone HB, Nguyen SL, Williams R, Ottomeyer T, Wortzman M, Jeffers M, Moy RL (2000) Efficacy of hydroquinone cream (USP 4%) used alone or in combination with salicylic acid peels in improving photodamage on the neck and upper chest. Dermatol Surg 26(4) 333-337... 

Balina LM, Graupe K (1991) The treatment of melasma 20% azelaic acid versus 4% hydroquinone cream. Int J Dermatol 30 893-895... 

Fig. 16.3. a Severe recalcitrant post-inflammatory hyperpigmentation secondary to acne excorians. b After a series of four salicylic acid 20 and 30% peels and 10% hydroquinone cream... 

Sample preparation for complex formulations, such as creams, can frequently be as simple as dissolving the cream in the totally organic mobile phase such as the ones typically used in normal-phase chromatography. Organic solutions of flurometholone [3, p. 677] and hydrocortisone acetate [3, p. 758] creams were assayed by HPLC and hydroquinone cream by TLC [3, p. 769]. A similiar approach has been applied to sample preparation of ointments. 

All of these hydroquinone creams are still fairly irritating to the skin, and many commercial formulations have been developed with new cosmeceutical technologies that are not available in pharmacies. ... 

Finally, it should be noted that hydroquinone poses a serious galenical problem, as it tends to oxidize quickly preparations containing hydroquinone have to be mixed and packaged in an oxygen-free atmosphere (in nitrogen). Preparations packaged in jars oxidize too quickly and lose most of their effectiveness within a few days. The ideal packaging for hydroquinone cream is a hermetically sealed, double-layer, aluminum tube. 

Pineda RT, Chan G, Gabriel T (2006) A randomized double blind placebo controlled comparative study on the safety and efficacy of 0.25% tetrahydrocurcumin (Turmeric) cream as depigmenting agent against 4% hydroquinone cream. RITM, Philippines, unpublished... 

Uses Emulsifier, emollient in cosmetics, anliperspirant creams and lotions, ointments, hydroquinone creams, shampoos, topical pharmaceuticals Properties APHA 50 max. brittle flakes, mild fatty char, odor m.p. 50 C HLB 5.4 acid no. 0.3 iodine no. 2 max. sapon. no. 1 pH 7.2 (3% aq. disp.) 100% cone. Lexemul PEG-200 DL [Inolex S. Black]... 

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