compounding HOTLINE

Q.I am a pharmacist in Mexico. A patient is allergic tomost oils and wants injectable estradiol. I tried saline,polyethylene glycol 400, benzyl alcohol, and polysorbate 80,but the suspended particles were too large for injection.

A.Estradiol is "...practically insoluble in water; soluble 1 in 28of alcohol [ethanol], 1 in 435 of chloroform, and 1 in 150of ether; soluble in acetone, dioxan, and solutions offixed alkali hydroxides; sparingly soluble in vegetable oils"(Martindale. The Extra Pharmacopoeia. 29th ed. London,England: Pharmaceutical Press; 1989:1407). Estradiol salts followa similar pattern; they are practically insoluble in water.Here are a few suggestions: If parenteral administration isrequired, try patch testing the patient for allergy to oils, seekingone yielding no reaction. If you can, switch the patient toeither transdermal administration (pluronic lecithin organogelgel vehicle) or oral capsules or troches for buccal or sublingualabsorption of the estradiol.

Estradiol 5 mg/mL in oil injection,calculated to make 100 mL

Ingredients:

Estradiol 0.5 g

Benzyl alcohol 5 mL

Sesame oil qs ad 100 mL

Supplies:

Sterile 0.2-μm filter (oil-compatible) or dry heat sterilizer

Procedure:

1. Accurately weigh/measure each ingredient.

2. Add the estradiol to the benzyl alcohol and mix well.

3. Add sufficient sesame oil to the mixture in (1) to bringto total final volume and mix well.

4. Sterilize the solution either by filtration or in dry heat.*

5. Package in sterile, tight, light-resistant containers.

Notes:

This preparation should be compounded only in accordancewith USP <795> and <797>. This preparation is forintramuscular injection.

No claims are made as to the uses, safety, efficacy, orbioavailability of this product. The formula is for informationalpurposes only.

*Oil-based solutions cannot be sterilized by autoclaving.

Estradiol cypionate in oil injection 5 mg/mL, calculated to make 100 mL

Ingredients:

Estradiol cypionate 0.5 g

Chlorobutanol anhydrous 0.54 g

Cottonseed NF qs ad 100 mL

Supplies:

Sterile vials

Dry heat sterilizer

Procedure:

1. Accurately weigh/measure each ingredient.

2. Add the estradiol cypionate to the chlorobutanol and mix well.

3. Add sufficient cottonseed oil to the mixture in (1) to bring to total final volume and mixwell.

4. Sterilize the solution either by filtration or in dry heat.*

5. Package in sterile containers and label.

Packaging:

Package in sterile, tight, light-resistant containers.

Notes:

This preparation should be compounded only in accordance with USP <795> and <797>. Thispreparation is for intramuscular injection.

No claims are made as to the uses, safety, efficacy, or bioavailability of this product. The formulais for informational purposes only.

*Oil-based solutions cannot be sterilized by autoclaving.

E-mail your compounding questions tocompounding@pharmacytimes.com

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