Quick-reference calculators and guides for common compounding dosage forms. Select a module below or use the tabs above.
Capsule capacity by size, powder density, and fill weight calculations.
Calculate PEG or silicone mold base quantities for troche formulations.
Displacement factor calculations for cocoa butter, Fattibase, and PEG bases.
Calculate fill weights, filler quantities, and overage for capsule compounding.
Percentage-to-weight conversions for topical bases and active ingredients.
Common pharmacy conversions, equivalences, and quick-reference tables.
Determine how much powder fits in each capsule size based on your powder's density.
How it works: Each capsule size has a standard volume (mL). Multiply by your powder's density (g/mL) to get the fill weight per capsule. Density varies — always measure your actual powder blend with a tapped density test.
| Capsule Size | Volume (mL) | Typical Fill (mg) @ 0.6 g/mL | Typical Fill (mg) @ 0.8 g/mL | Typical Fill (mg) @ 1.0 g/mL |
|---|---|---|---|---|
| 000 | 1.37 | 822 | 1096 | 1370 |
| 00 | 0.91 | 546 | 728 | 910 |
| 0 | 0.68 | 408 | 544 | 680 |
| 1 | 0.50 | 300 | 400 | 500 |
| 2 | 0.37 | 222 | 296 | 370 |
| 3 | 0.30 | 180 | 240 | 300 |
| 4 | 0.21 | 126 | 168 | 210 |
| 5 | 0.13 | 78 | 104 | 130 |
Calculate the amount of base needed for troche (lozenge) formulations.
Troche basics: Troches are oral lozenges designed to dissolve slowly in the mouth for buccal/sublingual absorption. Common bases include polyethylene glycol (PEG) blends, Polybase, and silicone molds with hard candy or chocolate bases.
Key formula: Total base needed = (Mold capacity × # of troches) − Total weight of active ingredients. Always add overage (10-15%) for loss during pouring.
| Base | Composition | Melt Temp | Notes |
|---|---|---|---|
| Polybase | Pre-made PEG blend | ~55-60°C | Most common, easy to use, good dissolution |
| PEG 1000 / 1450 (50:50) | Equal parts PEG 1000 + PEG 1450 | ~40-50°C | Softer base, faster dissolution, good for buccal |
| PEG 1450 / 8000 (75:25) | 75% PEG 1450 + 25% PEG 8000 | ~55-60°C | Harder base, slower dissolution |
| Silicone — Chocolate | Chocolate chips or wafers | ~45-50°C | Patient-friendly, flavored, slower release |
| Silicone — Hard Candy | Sugar/corn syrup/flavoring | ~150°C | Requires candy thermometer, most patient-friendly |
Calculate base quantities using displacement factors for suppository compounding.
Displacement Factor (DF): The number of grams of drug that displaces 1 gram of base. A DF of 1.5 means 1.5g of drug takes up the same space as 1g of base. Formula:
Base needed = (Mold capacity × qty) − (drug weight per unit × qty ÷ DF)
If your specific drug is not listed, a DF of 1.0 (no displacement adjustment) is a safe starting assumption. Always calibrate with test batches.
| Drug | Displacement Factor | Notes |
|---|---|---|
| Acetaminophen | 1.3 | |
| Aspirin | 1.1 | |
| Baclofen | 1.5 | |
| Bismuth subgallate | 2.7 | Very dense |
| Diazepam | 1.4 | |
| Diclofenac sodium | 1.4 | |
| Ibuprofen | 1.1 | |
| Indomethacin | 1.3 | |
| Ketamine HCl | 1.2 | |
| Ketoprofen | 1.1 | |
| Lidocaine | 1.2 | |
| Misoprostol | 1.0 | Very low dose, negligible displacement |
| Morphine sulfate | 1.6 | |
| Phenobarbital | 1.2 | |
| Prednisone | 1.3 | |
| Progesterone | 1.4 | Common in compounding |
| Promethazine | 1.3 | |
| Testosterone | 1.4 | |
| Zinc oxide | 4.0 | Very dense mineral |
Calculate active ingredient weight, filler quantity, and total blend for capsule formulations.
Process: Determine total capsule capacity (from packing stats), subtract the weight of all actives, and the remainder is your filler (typically microcrystalline cellulose, lactose, or a blend). Always add overage.
Convert percentage concentrations to weights for topical compounding.
How it works: For a w/w (weight-in-weight) formula, the percentage means grams of active per 100g of total product. Base quantity = Total weight − sum of all actives.
| Base | Type | Best For | Notes |
|---|---|---|---|
| VersaBase / Versatile Cream | O/W Cream | General topical, hormones | Elegant, non-greasy, good absorption |
| Lipoderm | Anhydrous | Transdermal delivery | High penetration, good for pain creams |
| PLO Gel | Lecithin gel | Transdermal, pain, ketamine | Pluronic + lecithin + IPP; forms gel at room temp |
| White Petrolatum | Ointment | Occlusive barrier | Greasy but excellent moisture barrier |
| Aquaphor | Ointment | Barrier + slight absorption | Contains lanolin, slightly emulsifying |
| HRT Cream Base | Vanishing cream | Hormone replacement | Designed for vaginal or topical hormone use |
| From | To | Multiply By |
|---|---|---|
| grams (g) | milligrams (mg) | 1,000 |
| milligrams (mg) | grams (g) | 0.001 |
| grams (g) | micrograms (mcg) | 1,000,000 |
| milligrams (mg) | micrograms (mcg) | 1,000 |
| kilograms (kg) | grams (g) | 1,000 |
| grains (gr) | milligrams (mg) | 64.8 |
| ounces (oz) | grams (g) | 28.35 |
| pounds (lb) | grams (g) | 453.6 |
| pounds (lb) | kilograms (kg) | 0.4536 |
| From | To | Multiply By |
|---|---|---|
| liters (L) | milliliters (mL) | 1,000 |
| teaspoon (tsp) | milliliters (mL) | 5 |
| tablespoon (tbsp) | milliliters (mL) | 15 |
| fluid ounce (fl oz) | milliliters (mL) | 29.57 |
| cup | milliliters (mL) | 236.6 |
| pint (pt) | milliliters (mL) | 473.2 |
| quart (qt) | milliliters (mL) | 946.4 |
| gallon (gal) | milliliters (mL) | 3,785 |
| Expression | Meaning | Example |
|---|---|---|
| 1% | 1 g per 100 mL (or 100 g) | 1% hydrocortisone = 1g per 100g cream |
| 1:1000 | 1 g per 1000 mL | Epinephrine 1:1000 = 1 mg/mL |
| 1:10,000 | 1 g per 10,000 mL | Epinephrine 1:10,000 = 0.1 mg/mL |
| mg/mL | Milligrams per milliliter | 10 mg/mL = 1% solution |
| mcg/mL | Micrograms per milliliter | 1 mcg/mL = 0.0001% |
| ppm | Parts per million = mg/L | 1 ppm = 1 mg/L = 0.0001% |
| Abbreviation | Meaning |
|---|---|
| qs | Quantity sufficient (add enough to reach target) |
| qs ad | Quantity sufficient to make (total amount) |
| aa | Of each (equal amounts) |
| w/w | Weight in weight |
| w/v | Weight in volume |
| v/v | Volume in volume |
| O/W | Oil-in-water emulsion |
| W/O | Water-in-oil emulsion |
| BUD | Beyond-use date |
| USP | United States Pharmacopeia grade |
| NF | National Formulary grade |
| MCC | Microcrystalline cellulose |
| PEG | Polyethylene glycol |
| PLO | Pluronic lecithin organogel |
| IPP | Isopropyl palmitate |