Physicochemical Properties of Branded and Generic Infusion Fluid Preparations: Results of a Comparative Experimental...

In Japan, four different types of hypotonic infusion fluids, namely, types 1-4, are available and used depending on the patient's condition. Although branded and generic products for each type of hypotonic infusion fluid are available, their physicochemical properties are unknown. For types 1 and 3 fluids, differences in the physicochemical properties of branded and generic products lead to different adverse events when administered. In the present study, we measured titration acidity, pH, and osmolality of branded and generic type 2 hypotonic infusion fluids, which have recently been recognized as useful for maintenance infusion among pediatric patients. We herein assessed their physicochemical information required while selecting a product in clinical practice. Experiments were performed using one branded and two generic products of type 2 hypotonic infusion fluids. Titration acidity was measured via neutralization titration, osmolality was measured via freezing point depression, and pH was measured via potentiometry using a glass electrode. Significant differences in titration acidity, which is a risk factor for metabolic acidosis, and pH, which is a risk factor for pH-dependent changes upon mixing, were observed between the branded and generic products. Our study indicates that titration acidity and pH should be evaluated appropriately to avoid adverse events in clinical practice while selecting a product of type 2 hypotonic infusion fluids. Our findings highlight the importance of evaluating the differences between branded and generic products, specifically when selecting it for pediatric patients with incompletely developed renal function and patients with impaired renal function.