Pharmacy Times

Compounding Hotline

Author: Martin A. Erickson III, RPh

Mr. Erickson is director of professional affairs at Gallipot Inc.


Q: Can you please provide a formulation for compounding diclofenac 6% and methyl salicylate and menthol 10% qsad pentravan?

A: Formulations for diclofenac gel as a pluronic lecithin organogel (PLO) vehicle and cream in Pentravan vehicle follow. Please note that PLO and Pentravan contain penetration enhancers for transdermal absorption of topically applied medication. PLO should be covered with an occlusive dressing. Incidentally, the PLO gel looks like a “cream.” Use a little ethanol 200 proof to dissolve/make a paste with the methyl salicylate and menthol, but verify the concentration of menthol with the prescriber.

Diclofenac 4% in PLO Gel—120 g

Ingredients, Quantity
Diclofenac sodium USP, 4.8 g
Ethanol 200 proof or suitable solvent, 4.8 mL
Lipoil, 28.8 mL
Polox 20% gel, qs ad 120 g

Procedure
1. Calculate the required quantity of each ingredient for the total amount to be prepared.
2. Accurately weigh and/or measure each ingredient.
3. Dissolve active ingredients in suitable solvent (ethanol or glycerin).
4. Add 28.8 mL of lipoil into above ingredients. Mix well.
5. Qs to 120 g with polox gel 20%. Mix thoroughly.
6. Package and label.

Notes: Preserve polox gel 20% in the refrigerator for liquid consistency. Store finished preparation at room temperature.


Diclofenac 8% in Pentravan—100 g

Ingredients, Quantity
Diclofenac sodium USP, 8 g
Propylene glycol USP, qs 0
Pentravan, qs ad 100 g

Procedure
1. Calculate the required quantity of each ingredient for the total amount to be prepared.
2. Accurately weigh and/or measure each ingredient.
3. Triturate the powders with the propylene glycol to form a smooth paste.
4. Levigate (3) with the Pentravan.
5. Run mixture in (4) through an Exacta ointment mill.
6. Transfer material in (5) to a suitable ointment jar.
7. Label the preparation.

Notes: Diclofenac sodium powder is hazardous if inhaled. Wear a face mask and/or work within a safety hood.■


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