Types of errors that can occur during compounding:
(1) unreasonable or irrational prescription
(2) omission of an essential ingredient or making an incorrect substitution
(3) addition of a wrong or an unwanted ingredient (chemical contamination)
(4) use of substandard or degraded ingredients
(5) adding a wrong amount of a component
(5a) incorrect dose or dosage calculation
(5b) incorrect weighing or measuring
(5c) incorrect dilution
(6) incorrect buffering or wrong pH
(7) failure to add a preservative or stabilizer
(8) incorrect reconstitution
(9) incorrect technique of preparation including proper temperature control
(10) inappropriate route of administration
(11) incorrect preparation of the delivery form (pill, tablet, capsule, etc)
(12) lack of sterility resulting in bacterial or fungal contamination
(13) chemical incompatibility
(14) incorrect labeling (no expiration date, wrong ingredients, etc)
(15) incorrect instructions to the patient
(16) improper storage or delivery
Sometimes no harm will come from an error but some can be life-threatening.