Hydroquinone is 1,4-benzenediol. Hydroquinone is structurally related to monobenzone. Hydroquinone occurs as fine, white needles. The drug is freely soluble in water and in alcohol and has a pK a of 9.96. Chemically, hydroquinone is designated as p-dihydroxybenzene; the empirical formula is C 6 H 6 O 2 ; molecular weight 110.1. The structural formula is:
CONTENTS:
ACTIVE INGREDIENT: Hydroquinone USP 4%.
OTHER INGREDIENTS (LUSTRA ® ): Purified Water USP, Phenyl Trimethicone, Glycerin 99% USP, Glyceryl Stearate (and) PEG-100 Stearate, Alcohol, Cetyl Alcohol NF, Cyclopentasiloxane (and) Polysilicone-11, Linoleic Acid, Glycolic Acid, Polyacrylamide (and) C13-14 Isoparaffin (and) Laureth-7, Cetearyl Alcohol (and) Ceteareth-20, Triethanolamine 99% USP, Tocopheryl Acetate USP, Hydrogenated Lecithin, Phenoxyethanol, Magnesium 1-Ascorbyl Phosphate NF, Benzyl Alcohol NF, Dimethiconol, Sodium Metabisulfite NF, Sodium Citrate USP, Disodium EDTA USP, Butylated Hydroxytoluene, Vitamin E USP, Carbomer NF, Fragrance.
OTHER INGREDIENTS (LUSTRA-AF ® ): Purified Water USP, Octyl Methoxycinnamate, Glycerin 99% USP, Phenyl Trimethicone, Glyceryl Stearate (and) PEG-100 Stearate, Cetyl Alcohol NF, Alcohol, Avobenzone, Cyclopentasiloxane (and) Polysilicone-11, Linoleic Acid, Glycolic Acid, Polyacrylamide (and) C 13-14 Isoparaffin (and) Laureth-7, Cetearyl Alcohol (and) Ceteareth-20, Triethanolamine 99% USP, Hydrogenated Lecithin, Tocopheryl Acetate USP, Phenoxyethanol, Benzyl Alcohol NF, Magnesium 1-Ascorbyl Phosphate NF, Dimethiconol, Sodium Metabisulfite NF, Sodium Citrate USP, Disodium EDTA USP, Butylated Hydroxytoluene, Vitamin E USP, Carbomer NF, Fragrance.
Topical application of hydroquinone produces a reversible depigmentation of the skin by inhibition of the enzymatic oxidation of tyrosine to 3-(3,4-dihydroxyphenyl) alanine (dopa) 1 and suppression of other melanocyte metabolic processes 2 . Exposure to sunlight or ultraviolet light will cause repigmentation which may be prevented by the broad spectrum sunscreen agents contained in LUSTRA-AF 3 .
LUSTRA and LUSTRA-AF are indicated for the gradual treatment of ultraviolet induced dyschromia and discoloration resulting from the use of oral contraceptives, pregnancy, hormone replacement therapy, or skin trauma.
LUSTRA or LUSTRA-AF should be applied to the affected areas twice daily, morning and before bedtime, or as directed by a physician. During and after the use of LUSTRA sun exposure should be limited, and a sunscreen agent or sun-protective clothing should be used to cover the treated areas, to prevent repigmentation. There is no recommended dosage for pediatric patients under 12 years of age except under the advice and supervision of a physician.
LUSTRA and LUSTRA-AF are contraindicated in any patient that has a prior history of hypersensitivity or allergic reaction to hydroquinone or any of the other ingredients. The safety of topical hydroqinone use during pregnancy or on children (12 years and under) has not been established.
SEE WARNINGS
A. Pregnancy Category C: Animal reproduction studies have not been conducted with topical hydroquinone. It is also not known whether hydroquinone can cause fetal harm when used topically on a pregnant woman or can affect reproductive capacity. It is not known to what degree, if any, topical hydroquinone is absorbed systemically. Topical hydroquinone should be used in pregnant women only where clearly indicated.
B. Nursing mothers: It is not known whether topical hydroquinone is absorbed or excreted in human milk. Caution is advised when hydroquinone is used by a nursing mother.
C. Pediatric usage: Safety and effectiveness in pe-diatric patients below the age of 12 years have not been established.
No systemic reactions have been reported. Occasional cutaneous hypersensitivity (localized contact dermatitis) may occur, in which case the medication should be discontinued and the physician notified immediately.
There have been no systemic reactions reported from the use of topical hydroquinone. However, treatment should be limited to relatively small areas of the body at one time, since some patients experience a transient skin reddening and a mild burning sensation which does not preclude treatment.
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REFERENCES |
1 C., A.B. Lerner, and T.B. Fitzpatrick. "Inhibition of Melanin Formation by Chemical Agents." Journal of Investigative Dermatology . 1952; 18:119-135. |
2 K., H. Obata, M. Pathak, and T.B. Fitzpatrick. "Mechanism of Depigmentation by Hydroquinone." Journal of Investigative Dermatology . 1974; 62:436-449. |
3 J.A., R.R. Anderson, F. Urbach, and D. Pitts. UVA, Biological Effects of Ultraviolet Radiation with Emphasis on Human Responses to Longwave Ultraviolet. Plenum Press, New York and London, 1978, p.151. |
LUSTRA and LUSTRA-AF should be stored at 15°-25°C (59°-77°F).
Covered by US Patent 5,932,612 and other pending patent applications.
Manufactured for: TaroPharma
a division of Taro Pharmaceuticals U.S.A., Inc., Hawthorne, NY 10532
by: Contract Pharmaceuticals Limited, Mississauga, Ontario L5N 6L6 CANADA
Made in Canada
LUSTRA® & LUSTRA-AF® are trademarks of Medicis Pharmaceutical Corporation, used under license by Taro Pharmaceuticals U.S.A., Inc. TaroPharma is a trademark of Taro Pharmaceuticals U.S.A., Inc.
Issued: September 2004
PK-4967-0 0904-0