Compounding Calculations

When creating new ingredients or setting up dosage forms in Compound Direct, you’ll encounter several important concepts that determine how formulations are calculated. These values ensure each compound is prepared accurately and consistently based on its intended dosage form.

These calculations help you:

• Use precise adjustment factors to account for variations in potency, assay values, or biological activity, ensuring the correct amount of active ingredient is used in every batch.
• Leverage automated calculations that instantly adjust ingredient quantities, apply batch-specific data, and flag potential issues before compounding begins.
• Tailor formulations to any dosage form with flexible methods that adapt calculations based on how the compound is administered, whether it’s a capsule, liquid, cream, or powder.

Here’s an overview of the factors you will encounter as you set up your new ingredients, along with key points to remember.

Ingredient roles

Each ingredient in a formulation is assigned a role: Active, Excipient, or Base, which determines how its quantity is calculated.

After placing ingredients and desired strength on the formulation page, hover over the info icon view calculations for each ingredient.

Active
When you add an active ingredient, Compound Direct calculates its percent,

and quantity

Quantity is the total amount needed for the batch, based on the prescribed strength, number of units, wastage, and adjustment factor.

based on the strength, adjustment factor, pack stats, number of units, and any wastage,

Wastage refers to the extra amount of an ingredient or formulation that is added to compensate for losses that may occur during the compounding process, such as material sticking to equipment, spillage, or transfer loss.

ensuring accurate dosing across the full batch.

Excipient
When you add an excipient, Compound Direct automatically calculates its quantity

based on the ingredients' pack stats, number of units, and any wastage.

Wastage refers to the extra amount of an ingredient or formulation that is added to compensate for losses that may occur during the compounding process, such as material sticking to equipment, spillage, or transfer loss.

Base
When a formula is QS’d (filled to a sufficient quantity), the system calculates an estimated quantity

of the base. When it’s not QS’d, the system calculates the exact quantity of base required to ensure each unit delivers the correct therapeutic dose.

Adjustment factors

When adding a new batch for an active ingredient, an adjustment factor may be entered.

An adjustment factor is a number used to ensure the correct amount of active ingredient is added to a formula, based on its actual strength. It accounts for factors likeassay values,

elemental percentages,

Elemental percentages refer to the proportion of a specific element (such as magnesium or zinc) within a compound, used when the prescribed dose refers to the element, not the full compound.

biological activity

Biological activity refers to the potency of an ingredient measured by its effect (not weight), commonly used for vitamins, enzymes, or hormones where dosing is based on International Units (IU).

(such as IU per gram),inactive components in commercial products,

Inactive components in commercial products are non-therapeutic substances (e.g., fillers or binders) mixed with the active ingredient in commercial preparations, which dilute the active concentration and require correction.

salt to base factor,

Salt to Base Factor adjusts the ingredient weight to account for any salt (e.g., HCL, citrate) so the correct amount of active ingredient is used. Check dosing documentation or a formulation specialist to see if correction is needed.

or other manual considerations depending on the ingredient.

In most cases, the adjustment factor is calculated using values from the

such as assay percentage or elemental composition. This calculation helps match the prescribed dose with the actual amount of active ingredient used. In Compound Direct, adjustment factors are applied only to active ingredients and the system instantly recalculates ingredient quantities as you enter data, helping ensure accuracy and flag issues before compounding begins.

Packing statistics

Packing statistics or pack stats show how much space a powder takes up in a capsule. In Compound Direct, they help prevent overfilling or underfilling, determining what the correct capsule size is needed, or how much is needed per dose. They are entered per batch, carry over to future batches, and can be estimated for smaller capsule sizes.

When setting up ingredients for capsules, first determine the capsule packing statistics for the powder ingredient. You can add the pack stats when creating a new ingredient, or edit them later from the ingredient page useful if you need to update the pack stats for a specific batch.

1. Go to ‘Settings’.
2. Click on the ‘Ingredients’ button.
3. Use the search bar to find the desired ingredient, then click its name to open the ingredient details.
4. Click the batch number of the specified ingredient batch.
5. Under Capsule Packing Statistics, select This ingredient is used in capsules to display the capsule size and pack stats table.
6. You can either manually enter the packing statistics for each capsule size or click ‘Generate’ to fill them automatically.
7. In the Generate Packing Statistics modal, enter the determined pack stats for the largest available capsule size.
8. Click the ‘Generate Pack Stats’ button to automatically calculate the pack stats for the corresponding smaller capsule sizes.
9. Click the ‘Save’ button.

Liquid density

When setting up a liquid ingredient, you may enter its density so the system can accurately calculate its volume. This is especially important in w/w formulas that include liquids but cannot be QS’d by volume, such as making a cream without topping up to a final weight or producing troches where volume adjustments aren’t possible. In these cases, liquids are weighed in grams rather than measured in millilitres.

Entering the density allows the system to convert between weight and volume accurately, ensure correct amounts are weighed, and integrate with balances so business owners can step away from the lab while still confirming the right quantities are dispensed, avoiding the inaccuracy that can occur when liquids are only measured by volume.

1. Go to ‘Settings’.
2. Click on the ‘Ingredients’ button.
3. Use the search bar to find the desired ingredient, then click its name to open the ingredient details.
4. Click the batch number of the specified ingredient batch.
5. Under Liquid Density, type down the liquid density of the ingredient.
6. Click the ‘Save’ button.

Powder density

When using an ingredient in powders, enter the powder density to allow accurate conversion between weight and volume. Powder density measures how much a loose, uncompacted powder weighs per millilitre of space. It reflects the natural volume a powder occupies without pressing or compressing it.

Powder density is the weight of a loose powder that fits into 1 mL of space, measured in mg/mL. It’s used in powder-based preparations, such as scoops, to calculate how much base to add so each portion contains the correct amount of active ingredient. Powder density is entered per batch and carries over to future batches, but it can be updated at any time if needed. It is only applied when the powder calculation method is selected.

1. Go to ‘Settings’.
2. Click on the ‘Ingredients’ button.
3. Use the search bar to find the desired ingredient, then click its name to open the ingredient details.
4. Click the batch number of the specified ingredient batch.
5. Under Density & Displacement, type down the powder density of the ingredient.
6. Click the ‘Save’ button.

Powder displacement

Displacement factor is how much space an ingredient takes up per gram, used to decide how much base to remove in a formulation. It’s vital in molded dosage forms like suppositories, troches, and gummies, where incorrect values can cause inconsistent dosing, poor texture, or wasted product. Displacement varies by ingredient and batch, so using the right value keeps the product accurate and consistent.

Compound Direct calculates displacement quantity automatically, using dosage form defaults or ingredient-specific overrides. It adjusts base weight in real time, shows values via the info icon, and updates instantly if units, wastage, or ingredient weights change. Accuracy depends on correct mold size, blank weight, base density, and displacement entries, with practical testing or trusted formulas preferred over estimates.

In the system, the displacement factor can be viewed and configured in two places: the Dosage Form settings and the Ingredient Batch settings.

Set a default displacement value in dosage form settings

1. Go to ‘Settings’.
2. Click on the ‘Dosage Forms’ button.
3. Choose the ‘Molded (w/w)’ calculation method.
4. In the search bar, select your Base Ingredient.
5. Enter the mold size (mL) and the blank weight (g).
6. Set the default displacement value to be applied to ingredients.
   • The standard default is 70%.
   • If unsure, check with your ingredient supplier.

Override the default displacement value on the ingredient batch

1. Go to the 'Settings' page.

2. Click on 'Ingredients'.

3. Select the desired ingredient.

4. Select the ingredient batch.

5. On the Edit Ingredient Batch page, scroll down to the Density and Displacement section.

6. Ensure the batch is closed and unapproved before making any changes.

7. In the Powder Displacement drop-down menu, you will see three options:

   • Inherit from Dosage Forms – Uses the displacement factor defined in the Dosage Form settings.
   • Standard Override – Allows you to enter a different displacement factor that will replace the one set in the Dosage Form settings.
   • Specify from Base – Lets you set a per-base displacement table. Enter the base name and the displacement factor specific to that base.

8. Click the ‘Save’ button.

Enter via quantity

When importing a reference formula into a formulation reference it may be necessary to enter the absolute values provided by the reference in order to convert them to their relative strength and percentages. This is important as Compound Direct requires the ingredients to be recorded as strength or percentage. Once toggled on, you can enter the grams for each solid ingredient for the given final quantity and wastage provided by the reference.

Calculation methods

When setting up your dosage form, you will encounter different calculation methods designed to best suit the nature of your preparation. The calculation method you choose determines whether the final units are measured in grams, milliliters, or discrete units such as capsules, scoops, or suppositories.

This selection directly affects how ingredients, especially liquids, are handled in the formulation, so it is important to interpret reference formulas carefully (for example, distinguishing between w/w, w/v, or v/v). Once a calculation method is selected, it applies to all past and future formulas created with that dosage form and includes specific settings based on the format.