Dermatology is one of the highest-volume areas of non-sterile compounding, and the base a formulation is built on matters as much as the active ingredient in it. This is a working reference on common bases, frequently compounded dermatologic preparations, and the stability variables worth checking before dispensing.
Common Compounding Bases
| Base | Character | Typical use |
|---|---|---|
| White petrolatum / Aquaphor-type | Highly occlusive, anhydrous | Barrier repair, very dry or fissured skin |
| Hydrophilic ointment / cream bases | Water-washable, moderate occlusivity | General-purpose compounding, better cosmetic acceptability |
| Carbopol (carbomer) gel bases | Aqueous gel, low occlusivity | Scalp and hair-bearing areas, acne-prone skin |
| PLO (pluronic lecithin organogel) | Enhanced transdermal delivery vehicle | Compounds intended for deeper or systemic absorption |
| Modern proprietary bases (e.g., Lipoderm-type) | Designed for actives compatibility and skin feel | Multi-ingredient compounded preparations |
Commonly Compounded Dermatologic Preparations
A few extemporaneous preparations come up often enough in dermatology-adjacent compounding to be worth knowing at a glance, though the specific formula, concentration, and rationale should always follow the prescriber's order and current compounding references:
- Diluted or combination corticosteroid preparations (for example, triamcinolone compounded into a moisturizing base) to adjust potency or improve tolerability for large-surface-area or pediatric use.
- Combination acne preparations (commonly compounding a retinoid, an antibiotic, and sometimes niacinamide into one vehicle) to improve adherence by reducing the number of separate products.
- Compounded minoxidil formulations, sometimes combined with additional actives, for androgenetic alopecia.
- Topical pain or neuropathic preparations (agents like ketamine, amitriptyline, or lidocaine in combination), which sit at the edge of dermatology and pain management compounding.
Stability Considerations
A handful of variables determine whether a compounded preparation holds up for its intended use period:
- Light sensitivity: tretinoin and other retinoids degrade with light exposure and require opaque packaging and counseling on storage.
- pH sensitivity: L-ascorbic acid and certain other actives are only stable within a narrow pH range, which affects both efficacy and shelf life.
- Preservation: any water-containing formulation needs an adequate preservative system to prevent microbial growth over its use period.
- Beyond-use dating: non-sterile compounded preparations should follow current USP <795> beyond-use date guidance rather than a default assumption, since BUDs vary by formulation type and packaging.
This is an educational reference and does not constitute compounding, medical, or pharmaceutical advice. Formulation decisions should always follow current USP compounding standards, the prescriber's order, and your pharmacy's standard operating procedures.