Potassium forms for supplement manufacturing

How the potassium forms compare

SoleChem supplies two potassium forms for food supplements: potassium chloride at 52.4 % potassium and potassium citrate at 38.3 % potassium, both on an anhydrous basis. No single form is the best form of potassium for every product. Chloride delivers the most potassium per gram. Citrate brings a different anion, a different taste and a second role as an acidity regulator.

The content gap matters because potassium label claims are usually large compared with trace minerals. For the same claim, potassium citrate needs about 37 % more powder than potassium chloride. In a capsule or tablet, that difference can decide the number of units per serving.

The figures above are on an anhydrous basis. Potassium citrate is also traded as a hydrate, and a hydrate carries less potassium per gram. Check the basis stated on the specification sheet and certificate of analysis before you fix the formula. The elemental content calculator handles the conversion once you have the assay.

Both salts dissolve in water, so both suit drinks, sachets and effervescent tablets. They differ in taste and handling. Potassium chloride has a salty taste with a bitter note at higher concentrations. Potassium citrate has a cooling, saline taste and is deliquescent, so it takes up moisture from humid air.

Choosing a form

The decision usually comes down to five points.

• Label claim per unit. At 100 mg potassium per unit you need 191 mg of potassium chloride or 261 mg of potassium citrate. At 200 mg per unit the figures are about 382 mg and 522 mg. Chloride leaves more room for other actives in a fixed capsule or tablet mass.
• Format. Both forms work in effervescent tablets and powders because they dissolve readily. In tablets, the higher content of chloride keeps tablet mass down. In capsules, the deliquescent nature of citrate calls for attention to shell choice and moisture exposure.
• Taste. In drinks and chewables, the bitter note of chloride is the main sensory challenge. Citrate fits easily into acidic flavour systems, and it can contribute to the acid–base balance of an effervescent or drink formula.
• Moisture and handling. Potassium citrate needs low-humidity dispensing, closed containers between uses and moisture-barrier packaging for the finished product. Potassium chloride is easier to handle in humid conditions but can still cake in poor storage.
• Cost per milligram of potassium. Potassium chloride is generally the lower-cost source per milligram of potassium. Citrate costs more per milligram because it carries a heavier anion. Ask for both forms in the quote form if you want to compare the two on your own claim.

The anion also counts on the label. Potassium chloride brings chloride into the product, and chloride is itself a mineral under EU food-supplement law. If you choose to declare chloride, include its contribution from this salt. Combining both forms is common when a formulator wants chloride’s content per gram with part of the potassium supplied as citrate for taste or pH.

EU regulatory status

Potassium is listed in Annex I of Directive 2002/46/EC as a mineral that may be used in food supplements. Annex II of the same Directive lists the permitted mineral substances. Potassium chloride and potassium citrate both appear there. The site’s guide to permitted vitamin and mineral forms explains how Annex II is structured and amended.

Both substances are also authorised food additives under Regulation (EC) No 1333/2008. Potassium chloride is E508 and potassium citrate falls under E332. Their purity specifications as additives are set in Regulation (EU) No 231/2012. The specification sheet states the standard the material meets.

Directive 2002/46/EC provides for EU maximum amounts of vitamins and minerals, but harmonised limits for potassium have not been adopted. Member states therefore set their own rules, and they differ. Some publish maximum levels, some require a model of the label to be notified to the competent authority when the product is placed on the market, and the competent authority of each member state publishes its requirements. See maximum levels by EU country for how these national rules work.

Classification is also national. A competent authority can decide that a particular potassium product falls under medicinal-product rules rather than food law. Check this in each target market for high-content products.

On the label, potassium is declared as the amount of the element per daily portion, not the amount of the salt. The labelling guide covers the declaration rules under Directive 2002/46/EC and the general labelling rules of Regulation (EU) No 1169/2011. For permitted claim wording, consult the EU Register of nutrition and health claims and the site’s health-claims guide.