Topical Solutions in Dermatology

Topical Solutions

• Aluminum Acetate Topical Solution:

  • Colorless with a faint acetous odor.
  • Used as an astringent wash or wet dressing after dilution (10-40 parts water).
  • Widely used in dermatological formulations.

• Calcium Hydroxide Topical Solution (Limewater):

  • Must contain at least 140 mg of Ca(OH)₂ per 100 mL.
  • Less soluble in hot water than cold.
  • Prepared by vigorously agitating excess Ca(OH)₂ (300 mg per 100 mL) with purified water for 1 hour.
  • Excess Ca(OH)₂ settles, leaving a saturated solution.
  • Should be stored in tightly closed containers in a cool place to prevent CO₂ absorption and maintain saturation.
  • Only the clear supernatant liquid is used.
  • Acts as an astringent, often combined with other ingredients in topical dermatological preparations.

• Coal Tar Topical Solution:

  • Alcoholic solution containing 20% coal tar and 5% polysorbate 80.
  • Nearly black viscous liquid with a naphthalene-like odor and sharp burning taste.
  • Local anti-eczematic used in treating chronic skin conditions after dilution (with about 9 volumes of water).
  • Can be combined with other agents (lotions, ointments, or solutions).

• Hydrogen Peroxide Topical Solution:

  • Contains 2.5-3.5% hydrogen peroxide (H₂O₂).
  • Preparation methods involve using either phosphoric or sulfuric acid on barium peroxide or electrolytic oxidation of concentrated sulfuric acid.
  • Dilute solutions are around 3% H₂O₂. Concentrated solutions are around 30%.
  • Releases 10 times its volume of oxygen.
  • Clear, colorless liquid, potentially odorless or with an ozone-like odor.
  • Degrades over time into oxygen and water; preservatives are often added.
  • Degradation accelerated by light and heat - store in tightly closed, light-resistant containers at or below 35°C.
  • Decomposed by organic matter and reducing agents; reacts with oxidizing agents.
  • Local anti-infective for skin and mucous membranes. Cleanses wounds mechanically through bubbling and frothing during oxygen release.

• Chlorhexidine Gluconate Solution:

  • Broad-spectrum antiseptic acting on gram-positive and gram-negative bacteria, including Pseudomonas aeruginosa.
  • 4% solution used as surgical scrub, hand wash, and skin cleanser.
  • Rare irritation, dermatitis, or photosensitivity with topical use.
  • Used as antiplaque and antigingivitis agent.

• Povidone Iodine Topical Solution:

  • Chemical complex of iodine and polyvinylpyrrolidone (PVP).
  • Contains approximately 10% iodine, slowly released when applied to skin.
  • Topical surgical scrub and antiseptic solution.
  • Effective due to iodine release.

• Thimerosal Topical Solution:

  • Water-soluble organic mercurial antibacterial agent.
  • Bacteriostatic and mild fungistatic properties.
  • Primarily used to disinfect skin, wounds, and abrasions.
  • Contains 0.1% thimerosal.
  • Used in dilutions (1:5000) for eye, nose, throat, and urethra.
  • Preservative in some pharmaceutical preparations (vaccines, biologics).
  • Light-sensitive - store in light-resistant containers.

Topical Oral (Dental) Preparations

• Benzocaine: Topical anesthetic for mouth pain, soreness, and irritation relief.

• Erythrosine Sodium Topical Solution/Tablets: Dental disclosing agents to reveal plaque buildup. Solution is applied to teeth; tablets are chewed (not swallowed).

• Eugenol: Dental analgesic, applied to cavities and as a protective agent. Pale yellow liquid with a clove-like odor and spicy taste.

• Lidocaine Oral Spray: Topical dental anesthetic (10 mg/spray).

• Nystatin Oral Suspension: Antifungal for oral fungal infections. Retain in mouth before swallowing.

• Saliva Substitutes: Electrolyte solutions in a carboxymethylcellulose base for dry mouth and throat relief.

• Sodium Fluoride Oral Solution/Tablets: Dental caries prophylaxis. Solution applied to teeth; dilute solution may be swallowed.

• Triamcinolone Acetonide Dental Paste: Topical anti-inflammatory agent for oral mucous membranes.

Rectal Solutions

• Retention Enemas: Used for local(e.g., hydrocortisone) or systemic(e.g., aminophylline) effects. Aminophylline uses minimize GI issues. Blood levels usually within 30 minutes. Corticosteroids for ulcerative colitis.

• Evacuation Enemas: Used to cleanse the bowel. Sodium phosphate, sodium biphosphate, glycerin, docusate potassium, and mineral oil forms common in pre-measured disposable containers. Usually effective in 5-10 minutes (user instruction important).

Explore the properties and uses of various topical solutions commonly used in dermatological treatments. This quiz covers Aluminum Acetate, Calcium Hydroxide, and Coal Tar solutions, detailing their preparation and application. Test your knowledge on these important medicinal formulations.