PP5007: Pharmaceutics and Drug Delivery Introduction
Ointments are semi-solid dosage forms intended for topical applications to the skin or mucous membranes. A topical dermatological product is designed to deliver drug into the skin in treating dermal disorders, with the skin as the target organ. Get legit paper writing services on Pharmacology now!
- Ointments are semi-solid preparations consisting of a medicament or mixture of medicaments dissolved or dispersed in a suitable base.
- Emulsifiable bases make the ointment miscible with tissue exudates and are more readily removable from the skin by washing.
APIs of whitfield ointment are benzoic acid and salicylic acid. Benzoic acid helps prevent infection caused by bacteria. Salicylic acid helps the body shed rough or dead skin cells.
- Apparatus: Beaker, Stirrer, Mortar and pestle, Measuring cylinder, Balance, Pipette, Bottle, Funnel, Glass- rod, Porcelin dish, water bath,
- Chemicals: Salicylic acid, Benzoic acid, Cetostearyl alcohol, Sodium Lauryl sulfate, White soft paraffin, Liquid paraffin and distilled water
- Methodology: Formula for 5 gm whitfield ointment
Preparation of Emulsifuing WAX:
- Cetostearyl alcohol 1230 mg
- Sodium Lauryl sulfate 135 mg
- Water 500 ul
Preparation of Emulsifuing Ointment:
- Emulsifying wax 1365 mg
- White soft paraffin 2275 mg
- Liquid paraffin 910 mg
Preparation of ointment:
- Salicylic acid (fine powder) 150 mg
- Benzoic acid (fine powder) 300 mg
- Emulsifying ointment 5000 mg
Preparation of Whitfield (Benzoic Acid and Salicylic Acid) Ointment Procedure :
- In a porcelin dish, melt cetostearyl alcohol over a water bath, add sodium lauryl sulfate and mix well. Then add water, heat and stir vigorously until frothing ceases. This is emulsifying wax (Step 1).
- To the emulsifying wax as prepared in step 1, add white soft paraffin followed by stirring well to mix properly. Then add liquid paraffin and mix until the content becomes cold. This is emulsifying ointment (Step 2).
- In a mortar, triturate salicylic acid and benzoic acid into fine powders. Gradually add a smaller portion of the melted emulsifying ointment, stir until smooth. Add the remainder of emulsifying ointment and mix thoroughly.
- Transfer to a clean container and label the container.
Preparation of Whitfield (Benzoic Acid and Salicylic Acid) Ointment Uses:
- Benzoic acid is an antibacterial and antifungal agent.
- Salicylic acid is a keratolytic agent.
Preparation of Whitfield (Benzoic Acid and Salicylic Acid) Ointment Reflective questions:
- In your lab report, write down the functions of all excipients used for the preparation of the ointment.
- If you have been provided salicylic acid (99.5% potency) and benzoic acid (99.7% potency), calculate the amount both salicylic acid (99.5% potency) and benzoic acid for the formulation of an ointment of a total amount of 5kg.
Overview
Ointments represent semi-solid dosage forms primarily designed for topical application to the skin or mucous membranes. These topical dermatological products are tailored to deliver medications to the skin, making it the target organ for treatment. Whitfield Ointment, in particular, is a well-known example. It is composed of active pharmaceutical ingredients (APIs), including benzoic acid and salicylic acid, aimed at preventing infections and promoting skin cell shedding.
Components of Whitfield Ointment
Active Pharmaceutical Ingredients (APIs):
- Benzoic Acid: This component serves as an antibacterial agent, effectively preventing bacterial infections.
- Salicylic Acid: Salicylic acid has keratolytic properties, aiding in the exfoliation of rough or dead skin cells.
Excipients (Formulation Components):
- Emulsifying Wax: This consists of cetostearyl alcohol and sodium lauryl sulfate, enhancing the miscibility of the ointment with tissue exudates and improving its washability from the skin.
- White Soft Paraffin: White soft paraffin is included in the formulation to provide a suitable base for the ointment.
- Liquid Paraffin: Liquid paraffin is another component of the ointment’s base.
- Distilled Water: Water is essential for the preparation of the emulsifying wax, contributing to the ointment’s overall formulation.
Methodology for Whitfield Ointment Preparation
Step 1: Preparation of Emulsifying Wax
- Cetostearyl alcohol (1230 mg)
- Sodium Lauryl sulfate (135 mg)
- Water (500 µl)
Step 2: Preparation of Emulsifying Ointment
- Emulsifying wax (as prepared in Step 1) (1365 mg)
- White soft paraffin (2275 mg)
- Liquid paraffin (910 mg)
Step 3: Preparation of Ointment
- Salicylic acid (fine powder) (150 mg)
- Benzoic acid (fine powder) (300 mg)
- Emulsifying ointment (as prepared in Step 2) (5000 mg)
Procedure:
- Melt cetostearyl alcohol in a porcelain dish over a water bath. Add sodium lauryl sulfate and mix thoroughly.
- Introduce water gradually while heating, stirring vigorously until frothing ceases, forming the emulsifying wax.
- To the emulsifying wax, add white soft paraffin, mixing well. Follow this by adding liquid paraffin, continuing to mix until the content cools and solidifies, resulting in the emulsifying ointment.
- In a mortar, triturate salicylic acid and benzoic acid into fine powders. Add a small portion of the melted emulsifying ointment, stirring until smooth. Gradually incorporate the remaining emulsifying ointment, ensuring thorough mixing.
- Transfer the final ointment to a clean container and label it accordingly.
Utilization and Functions
Whitfield Ointment is designed to treat dermal disorders, with benzoic acid serving as an antibacterial and antifungal agent and salicylic acid acting as a keratolytic agent.
Reflective Questions:
In the lab report, it is essential to document the functions of all excipients used in the ointment’s preparation. Additionally, if provided with salicylic acid (99.5% potency) and benzoic acid (99.7% potency), one can calculate the required amounts of both APIs for formulating an ointment with a total quantity of 5 kg. This calculation is necessary to ensure precise dosage and effectiveness in the final product.