NOVACALAMINE S 15%/2%W/V LOTION

Indications

• Mild skin irritations
• Insect bites
• Sunburn
• Rashes
• Prickly heat

Dosage

Children: Refer to the BNF for Children for appropriate dosing guidelines based on age and condition.

Adults: Apply to the affected area as needed, usually 2 to 4 times daily.

Mechanism of action

Calamine exerts its effects mainly through the astringent properties of zinc oxide and the soothing effects of ferric oxide. It helps to dry out oozing and weeping skin, while also providing a cooling sensation to alleviate discomfort.

Pharmacodynamics

The pharmacodynamics of calamine involve its ability to act as a protective barrier on the skin, reducing irritation and discomfort associated with various skin conditions. The astringent properties help to reduce moisture and inflammation, making it effective for soothing skin irritations.

Pharmacokinetics

Calamine is applied topically and is not significantly absorbed into systemic circulation, which minimizes systemic side effects. Its local effects are immediate upon application, providing rapid relief from symptoms like itching and inflammation.

Pregnancy

Calamine is generally considered safe for use during pregnancy, as it is a topical agent with limited systemic absorption.

Breast-feeding

Calamine is also considered safe for use during breastfeeding, as it is unlikely to pose a risk to the nursing infant.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Calamine lotion
• Calamine cream

Indications

• Acne vulgaris
• Scabies
• Seborrheic dermatitis
• Dandruff
• Pityriasis versicolor

Dosage

Children: Refer to

Adults: Refer to specific product instructions or BNF for appropriate topical application guidance.

Mechanism of action

Topically applied sulfur has mild antifungal and antibacterial activity. It is believed that sulfur forms hydrogen sulfide and/or polythionic acid upon application, which may exert germicidal effects. In vitro studies suggest that sulfur's antifungal activity is primarily due to its keratolytic action, which leads to the shedding of fungal spores and hyphae. The drug exhibits potent inhibitory effects against some streptococci and moderate effects against Staphylococcus aureus, while showing no activity against gram-negative bacteria. Its antibacterial effects may also result from the inactivation of sulfhydryl groups in bacterial enzyme systems. Additionally, sulfur is toxic to Sarcoptes scabiei, the parasite responsible for scabies.

Pharmacodynamics

Sulfur's pharmacodynamic properties include its keratolytic action, which helps in exfoliating the outer layer of skin and reducing the build-up of keratin. The antibacterial and antifungal activities contribute to its effectiveness against skin infections and conditions like acne. The exact pharmacodynamic pathways are not fully defined, but the combination of keratolytic, antibacterial, and antifungal effects underpins its therapeutic use in dermatology.

Pharmacokinetics

Sulfur is primarily used topically, and as such, its systemic absorption is minimal. Its local effects are achieved through direct application to the skin, where it acts on the surface and within the stratum corneum. The pharmacokinetics of sulfur involve minimal penetration into systemic circulation, leading to a lower risk of systemic side effects. The onset of action is relatively quick due to its localized effects.

Adverse effects

• Skin irritation
• Dryness
• Stinging
• Redness
• Peeling

Precautions

• Use with caution in patients with sensitive skin
• Avoid contact with eyes and mucous membranes
• Discontinue use if severe irritation occurs

Pregnancy

There are no adequate and well-controlled studies in pregnant women. Use only if clearly needed and the benefits outweigh the risks.

Breast-feeding

It is unknown if sulfur is excreted in human milk. Caution should be exercised when administered to a nursing woman.

Storage

Store in a cool, dry place away from moisture. Keep out of reach of children.

Formulations

• Topical cream
• Topical ointment
• Topical lotion
• Topical soap

Mechanism of action

Topically applied sulfur has mild antifungal and antibacterial activity. It has been suggested that when applied topically to the skin, sulfur forms hydrogen sulfide and/or polythionic acid, which may exert germicidal activity. In vitro studies indicate that sulfur has little if any fungistatic or fungicidal activity. Therefore, sulfur's antifungal activity probably results largely from its keratolytic action, causing shedding of fungal spores and hyphae embedded within the stratum corneum. In vitro, sulfur has been shown to have some antibacterial activity; the drug has a potent inhibitory effect against some streptococci, a moderate inhibitory effect against Staphylococcus aureus, and no activity against gram-negative bacteria. It has been suggested that the drug's antibacterial activity may partly result from inactivation of sulfhydryl groups contained in bacterial enzyme systems, since the antibacterial effect of the drug has reportedly been neutralized by addition of cysteine and other sulfhydryl-containing compounds to the culture medium. Topically applied sulfur is reportedly toxic to the parasitic arthropod Sarcoptes scabiei. The exact mechanism(s) of action of "sulfur" in the treatment of acne is not fully understood but is presumed to involve the drug's keratolytic and antibacterial effects. Although some studies indicate that "sulfur" may also be comedogenic, other studies have been unable to substantiate this effect and the drug generally is considered effective in the topical treatment of acne. The aim of this research was to analyze the effects and the modes of action of elemental sulfur (S(0)) in bioluminescence and respiration of Vibrio fischeri cells and the enzymes crude luciferase, pure catalase, and alcohol dehydrogenase (ADH). Metallic copper removed sulfur and reduced the toxicity of acetone extracts of sediment samples analyzed in the bioluminescence test. The sulfur inhibition of cell bioluminescence was noncompetitive with decanal, the luciferase substrate; reversible, with maximum toxicity after 15 min (EC50 = 11.8 ug/L); and almost totally recovered after 2 hr. In vitro preincubation of crude luciferase extract with sulfur (0.28 ppm) weakly inhibited bioluminescence at 5 min, but at 30 min the inhibition reached 60%. Increasing the concentration of sulfur in the parts per million concentration range in vitro decreased bioluminescence, which was not constant, but depended on exposure time, and no dead-end/total inhibition was observed. The redox state of enzymes in the in vitro system significantly affected inhibition. Hydrogen peroxide restored fully and the reducing agent dithiothreitol, itself toxic, restored only partially luciferase activity in the presence of sulfur. Sulfur (5.5 ppm) slightly inhibited ADH and catalase, and dithiothreitol enhanced sulfur inhibition. High sulfur concentrations (2.2 ppm) inhibited the bioluminescence and enhanced the respiration rate of V. fischeri cells. Elemental sulfur data were interpreted to show that sulfur acted on at least a few V. fischeri cell sites: reversibly modifying luciferase at sites sensitive to/protected by oxidative and reducing agents and by affecting electron transport processes, resulting in enhanced oxygen consumption. Sulfur together with an enzyme reducing agent inhibited the oxidoreductive enzymes ADH and catalase, which have /thiol/ groups, metal ion cofactors, or heme, respectively, in their active centers. Sulfur must be converted to pentathionic acid (H2S5O6) in order to exert germicidal action. Presumably oxidation of sulfur to pentathionic acid is accomplished by certain microorganisms or by epidermal cells when element is applied to skin. Sulfur possesses a keratolytic property, which may be the basis for the therapeutic action of the element in certain cutaneous disorders unassociated with infection.