Spatula, Ointment/Palette Knife

Quick Answer: An ointment spatula, also called a palette knife, is a spatula with a long, flexible, blunt-edged metal blade and a handle. In pharmacy it is used to levigate powders into bases and to mix ointments and creams on an ointment slab.

Flexible Blade, Flat Slab

Compounding an ointment means working a fine powder evenly into a greasy or creamy base. The palette knife does this by pressing and spreading the mixture across a flat glass or porcelain ointment slab, then scraping it back into a heap and repeating. A flexible blade lies flat against the slab, so the shearing action breaks up clumps of powder and leaves a smooth, gritless product. The blunt edge and rounded tip mean the blade spreads rather than cuts.

Two standard techniques depend on this tool. In levigation, the powder is first rubbed with a small amount of a compatible liquid to form a smooth paste before it is added to the base. In geometric dilution, a small amount of active powder is mixed with an equal amount of base, then the mixture is doubled with fresh base step by step until everything is uniform. Both are routine in pharmaceutics practicals, which is why the ointment spatula is basic pharmacy lab equipment, found in the Pharmacy range of many college stores.

Pharmaceutics texts note that some ingredients, such as iodine and certain metal salts, react with a steel blade; for those a non-metal tool such as a plastic spatula is used instead.

Applications

• Incorporating powders into ointment bases in pharmaceutics practicals
• Levigating zinc oxide or similar powders into a smooth paste
• Transferring finished ointment from slab to jar
• Mixing and spreading pastes or paints in art and craft work, as a palette knife

Specifications

Care & Handling

• Scrape off greasy bases first, then wash in hot water with detergent to remove the film.
• Store the spatula flat so the flexible blade does not take a permanent bend.
• Do not use the blade to prise lids or cut materials.
• Keep separate spatulas for medicated and non-medicated preparations in teaching labs.

Why Choose LabEquip

Pharmacy colleges, D.Pharm and B.Pharm teaching laboratories and hospital dispensing units are the usual buyers. LabEquip lists this palette knife in the General Lab Products range; send blade length preferences and quantities through the contact page.

Frequently Asked Questions

What is the difference between an ointment spatula and a laboratory spatula?

An ointment spatula has a long, flexible, blunt blade on a handle, designed for pressing and spreading semi-solids on a slab. A laboratory spatula is stiffer and smaller, designed for transferring dry solids.

What is levigation?

Levigation means rubbing a powder with a small amount of liquid that does not dissolve it, to form a smooth paste. The paste is then worked into the ointment base, which prevents gritty particles in the final product.

What surface should the ointment be mixed on?

A glass or porcelain ointment slab, or disposable ointment paper for small amounts. The surface should be smooth, hard and easy to clean.

Why is the blade flexible?

A flexible blade can be pressed flat against the slab to shear and spread the mixture. A stiff blade only touches with its edge and mixes less evenly.

Which ingredients should not be mixed with a steel blade?

Pharmaceutics references list iodine and some metal salts among ingredients that can react with metal. For these, a hard rubber or plastic spatula is used instead.

How do I clean greasy ointment bases off the blade?

Scrape off as much as possible with a tissue, then wash in hot water with detergent. Stubborn paraffin-based residues can be removed with a little alcohol before washing.

Last Updated: September 2026