Iodine Throat Paint, commonly known as Mandl’s Paint, is a pharmaceutical formulation used as a topical antiseptic for treating throat infections. This experiment guides students through the preparation of 100 mL of Mandl’s Paint, highlighting the role of each ingredient and the correct lab procedure. Iodine serves as the active antimicrobial agent, while potassium iodide increases its solubility in water. Glycerin acts as the vehicle that not only thickens the solution but also soothes the mucous membranes, making the product effective and patient-friendly. This formulation is widely included in pharmacopoeias and is essential in pharmaceutical chemistry practicals.

Aim: Preparation of Iodine Throat Paint (Mandl’s Paint)

References

1. Indian Pharmacopoeia – Monograph on Mandl’s Paint.
2. Martindale: The Complete Drug Reference – Section on Topical Antiseptics.
3. Research articles on “Iodine-Based Antiseptics” from PubMed.

Objective: To prepare 100 mL of Iodine Throat Paint (Mandl’s Paint) as per standard pharmaceutical formulations for use as a topical antiseptic for throat infections.

Materials Required

Chemicals:

• Iodine: 1.25 g
• Potassium Iodide: 2.50 g
• Glycerin: 25 mL
• Distilled Water: q.s. to 100 mL

Equipment:

• Analytical balance
• Beakers (100 mL, 250 mL)
• Measuring cylinder (10 mL, 100 mL)
• Stirring rod
• Funnel
• Amber-colored glass bottle
• Dropper

Principle

Mandl’s Paint is a throat antiseptic preparation where iodine serves as the active ingredient. Potassium iodide enhances the solubility of iodine in water. Glycerin is used as a vehicle to provide viscosity, ensure uniform application, and protect the throat mucosa.

Procedure

1. Dissolution of Potassium Iodide:
2. Weigh 2.50 g of potassium iodide and transfer it into a 100 mL beaker.
3. Add 10 mL of distilled water and stir until the potassium iodide dissolves completely.
4. Addition of Iodine:
5. Weigh 1.25 g of iodine and gradually add it to the potassium iodide solution with constant stirring.
6. Continue stirring until the iodine dissolves completely. A clear reddish-brown solution is formed.
7. Addition of Glycerin:
8. Measure 25 mL of glycerin using a measuring cylinder and add it to the iodine solution.
9. Stir thoroughly to ensure uniform mixing.
10. Final Volume Adjustment:
11. Add distilled water q.s. to make the total volume up to 100 mL. Mix well.
12. Packaging:
13. Transfer the prepared solution into an amber-colored bottle to protect it from light.
14. Ensure the bottle is airtight and attach a dropper cap.

Label

• Product Name: Iodine Throat Paint (Mandl’s Paint)
• Usage: Apply a small amount to the throat using a cotton swab or applicator as directed by a physician.
• Storage: Store in a cool, dark place. Keep away from direct sunlight.
• Precautions: For external use only. Avoid ingestion.

Precautions

1. Handle iodine with care, as it can stain skin and surfaces.
2. Use accurate weighing techniques to ensure proper concentration.
3. Maintain sterile conditions during preparation to avoid contamination.
4. Keep the preparation in an amber-colored bottle to prevent iodine degradation due to light exposure.

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Frequently Asked Questions (FAQs)

1. What is the purpose of potassium iodide in Mandl’s Paint?

Answer: Potassium iodide enhances the aqueous solubility of iodine, allowing it to dissolve completely in the solution and increasing its effectiveness as an antiseptic.

2. Why is glycerin used in this preparation?

Answer: Glycerin serves as a vehicle and soothing agent, providing viscosity for better application and helping to protect throat mucosa from irritation.

3. Can Iodine Throat Paint be ingested?

Answer: No, it is for external use only. It should be applied topically to the throat using a cotton swab or applicator under medical supervision.

4. Why should the solution be stored in an amber-colored bottle?

Answer: Iodine is photosensitive and can degrade when exposed to light. Amber-colored bottles block UV rays, preserving the stability and potency of the formulation.

5. What are the key precautions during preparation?

Answer:

• Handle iodine carefully to avoid staining and irritation.
• Use accurate weighing and sterile techniques.
• Store in a cool, dark place to prevent degradation.
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