FUNBACT-A 360ML HOMOGENEOUS LIQUID

Indications

• Hyperpigmentation
• Melasma
• Post-inflammatory hyperpigmentation
• Age spots

Dosage

Children: Refer to the BNF for Children for appropriate dosing information, as pediatric dosing may differ significantly from adult recommendations.

Adults: Topical application of hydroquinone is typically applied to the affected areas twice daily. Patients should follow specific product guidelines and consult healthcare professionals for individualized treatment plans.

Mechanism of action

Hydroquinone reduces melanin pigment production through inhibition of the tyrosinase enzyme, which is involved in the initial step of the melanin pigment biosynthesis pathway. This inhibition decreases the overall production of melanin, leading to a lighter skin appearance.

Pharmacodynamics

The pharmacodynamic effects of hydroquinone are largely related to its ability to modulate melanin synthesis in melanocytes by inhibiting tyrosinase activity. Prolonged exposure to hydroquinone can lead to a gradual lightening of the skin. However, the drug's efficacy may vary among individuals based on skin type and the extent of hyperpigmentation.

Pharmacokinetics

Hydroquinone is absorbed through the skin, reaching systemic circulation to some extent. The metabolic pathways of hydroquinone include its conversion to various reactive metabolites, which can generate reactive oxygen species and may lead to oxidative stress. Hydroquinone has a half-life that varies based on the route of administration and individual metabolism, but specific pharmacokinetic parameters are not well defined in the literature.

Adverse effects

• Skin irritation
• Erythema
• Hypopigmentation
• Allergic contact dermatitis

Precautions

• Use with caution in individuals with a history of skin sensitivity or allergy
• Avoid prolonged exposure to sunlight or ultraviolet light during treatment
• Not for use on broken or inflamed skin

Pregnancy

Hydroquinone should be used during pregnancy only if clearly needed, as safety in pregnancy has not been established.

Breast-feeding

Caution is advised when using hydroquinone while breastfeeding, as it is not known whether it is excreted in human milk.

Storage

Store at room temperature, away from light and moisture. Keep out of reach of children.

Formulations

• Cream
• Gel
• Lotion

Indications

• Prevention of vitamin E deficiency
• Antioxidant therapy
• Support in conditions related to oxidative stress

Dosage

Children: Refer to BNF for Children for specific dosage guidelines.

Adults: Refer to BNF for specific dosage guidelines.

Mechanism of action

Tocopherol acts as a radical scavenger, primarily functioning as an antioxidant for lipid bilayers. It donates hydrogen atoms to free radicals, trapping them and preventing cellular damage. Its effectiveness is influenced by its location within the membrane and its interaction with cytosolic reductants like ascorbate. Tocopherol can trap multiple radicals, including alkyl and peroxy radicals.

Pharmacodynamics

The antioxidant properties of tocopherol lead to significant pharmacodynamic effects, including the inhibition of cell death through modulation of protein kinase C (PKC). Tocopherol also exhibits anti-inflammatory effects, which can be attributed to its influence on cytokines, prostaglandins, prostanoids, and thromboxanes. These interactions may contribute to its protective effects in various pathological conditions.

Pharmacokinetics

Tocopherol is absorbed in the intestines and its bioavailability can be influenced by dietary fat intake. It is transported in the plasma primarily bound to lipoproteins. Tocopherol is stored in adipose tissue and the liver, and its elimination occurs through bile and urine. The half-life of tocopherol can vary depending on the individual's nutritional status and other factors.

Pregnancy

Tocopherol is generally considered safe during pregnancy, but it is advisable to consult a healthcare provider before use.

Breast-feeding

Tocopherol is excreted in breast milk, and while it is considered safe, a healthcare provider should be consulted for specific recommendations.

Storage

Store in a cool, dry place away from direct sunlight.

Mechanism of action

Hydroquinone reduces melanin pigment production through inhibition of the tyrosinase enzyme, which is involved in the initial step of the melanin pigment biosynthesis pathway. Hydroquinone takes several months to take effect. Benzene is a well-established human carcinogen. Benzene metabolites hydroquinone (HQ) and benzoquinone (BQ) are highly reactive molecules capable of producing reactive oxygen species and causing oxidative stress. /This study/ investigated the role of the Nrf2, a key nuclear transcription factor that regulates antioxidant response element (ARE)-containing genes, in defense against HQ- and BQ-induced cytotoxicity in cultured human lung epithelial cells (Beas-2B). When the cells were exposed to HQ or BQ the activity of an ARE reporter was induced in a dose-dependent manner, meanwhile Nrf2 protein levels were elevated and accumulated in the nucleus. Increased expression of well-known Nrf2-dependent proteins including NQO1, GCLM, GSS and HMOX was also observed in the HQ/BQ-treated cells. Moreover, transient overexpression of Nrf2 conferred protection against HQ- and BQ-induced cell death, whereas knockdown of Nrf2 by small interfering RNA resulted in increased apoptosis. /This study/ also found that the increased susceptibility of Nrf2-knockdown cells to HQ and BQ was associated with reduced glutathione levels and loss of inducibility of ARE-driven genes, suggesting that deficiency of Nrf2 impairs cellular redox capacity to counteract oxidative damage. Altogether, these results suggest that Nrf2-ARE pathway is essential for protection against HQ- and BQ-induced toxicity.

Mechanism of action

Tocopherol acts as a radical scavenger. It mainly acts as an antioxidant for lipid bilayers. Tocopherol's functions depend on the H-atom donating ability, location, and movement within the membrane, as well as the efficiency in the radical recycling by some cytosolic reductants such as ascorbate. Tocopherol actions are related to the trap of radicals, and it has been shown that even in the absence of substituents in the ortho-positions, tocopherol can trap more than two radicals. The type of radicals available for tocopherol are alkyl and peroxy.

Pharmacodynamics

The antioxidant effects of tocopherol can be translated into different changes at the pharmacodynamic level. In vitro studies have shown that this antioxidant activity can produce modification in protein kinase C (PKC) which will later be translated into an inhibition of cell death. Some other derivate effects are the anti-inflammatory properties of tocopherol which can be related to the modulation of cytokines or prostaglandins, prostanoids and thromboxanes.