Powder Form of Potassium Chloride
Potassium chloride powder is the crystalline, white, odorless form of the electrolyte replenisher that is freely soluble in water and used as the active ingredient in various oral potassium supplements, including microencapsulated formulations in tablets and extemporaneously prepared oral solutions. 1
Physical and Chemical Properties
- Potassium chloride (KCl) occurs as a white, crystalline powder with a saline taste 1
- It is freely soluble in water but practically insoluble in ethanol 1
- The powder form is odorless and represents the pure chemical compound before formulation into various dosage forms 1
Clinical Formulations Using Potassium Chloride Powder
Microencapsulated Tablet Formulations
- Extended-release tablets contain microencapsulated potassium chloride crystals that disperse upon tablet disintegration, with 750 mg of powder providing 10 mEq and 1500 mg providing 20 mEq of potassium 1
- The microencapsulation technology slows potassium release to reduce the likelihood of high localized concentrations within the gastrointestinal tract 1
- In simulated gastric fluid at 37°C, these tablets begin disintegrating into microencapsulated crystals within seconds and completely disintegrate within 1 minute 1
Extemporaneously Prepared Oral Solutions
- Potassium chloride powder can be used to prepare oral solutions when commercial preparations are unavailable, particularly for pediatric patients who cannot swallow tablets 2
- A stable 1 mMol/mL oral solution can be prepared by withdrawing 25 mL of potassium chloride 14.9% and adding Ora-Sweet SF to 50 mL in a metered flask 2
- This extemporaneously prepared solution maintains at least 91% of initial concentration for 28 days when stored refrigerated at 2°C to 8°C in amber glass bottles, with no notable pH changes or microbial growth 2
Safety Considerations for Powder Formulations
Storage and Handling
- Concentrated potassium chloride should be removed from clinical areas except critical care settings, and when kept on wards, must be stored in locked cupboards separate from all other solutions 3
- Proper protocols should monitor removal, use, and restocking of potassium chloride, including checking drug use against prescription orders 3
- Ampoules and containers of potassium chloride must be distinguishable from other injectable preparations through distinct, standardized labeling and packaging 3
Preparation Safety
- Pre-prepared intravenous infusions containing potassium are strongly preferred over bedside preparation to minimize medication errors 3, 4
- Needed infusions should be prepared in the pharmacy rather than at the bedside 3
- Similar packaging to other solutions and storage in close proximity have contributed to preparation errors 3
Clinical Toxicity Considerations
- Potassium chloride is extensively used as a potassium supplement both therapeutically and by the general public in the form of salt substitutes 5
- Oral overdose requires a large enough dose to overcome normal excretory mechanisms, with much larger doses needed in patients with normal renal function compared to those with compromised renal function 5
- Potassium toxicity manifests as cardiovascular changes with ECG abnormalities, neuromuscular weakness and ascending paralysis, and gastrointestinal symptoms including nausea, vomiting, and potential mucosal necrosis 5
Acid-Base Balance Effects
- Potassium chloride shifts acid-base balance toward acidotic values in normal rats and corrects metabolic alkalosis in hypokalemic rats 6
- In potassium deficiency combined with metabolic alkalosis, potassium chloride is preferable to organic potassium salts (acetate, aspartate, malate) since it corrects both electrolyte disturbances simultaneously 6
- Organic potassium salts cause an increase in alkalosis, with acetate acting stronger than aspartate and malate 6