Determination of Propylene Glycol in Low Volume Plasma and Urine Samples of Neonates by LC with Photodiode Array Detection

Excipients in Neonatal Medicinal Products: Never Prescribed, Commonly Administered

To attain effective and safe pharmacotherapy, formulations in (pre)term neonates should enable extensive dose flexibility. During product development and subsequent authorization and clinical use of such formulations, there is also a need for informed decisions on excipient exposure: in addition to the need to improve the knowledge on active compounds, there is a similar need to improve the knowledge on excipients in neonates. Excipients are added to formulations as co-solvent, surfactant, preservative, colorant and/or sweetener as vehicle(s) to result in a suitable (e.g. taste, shelf life, stability) product. Progress has been made in the awareness, knowledge and access to this knowledge on the clinical pharmacology of excipients in neonates. This is thanks to different initiatives focussing on epidemiological data, excipient pharmacokinetics, or building datasets to create this knowledge. We highlight the Safe Excipient Exposure in Neonates and Small Children (SEEN) and propylene glycol project to illustrate the feasibility to build knowledge, and discuss the methods applied and problems observed during these studies. The information generated in these and other studies (European Study on Neonatal Exposure to Excipients, ESNEE) should be integrated in repositories like the Safety and Toxicity of Excipients for Paediatrics (STEP) to facilitate access to all stakeholders. This merged knowledge should have impact and assist in improving the quality of risk assessment and decision making during drug development, applying a risk-benefit framework (explicit justification of excipients, plan product development early and engage all stakeholders, data sharing and modeling, challenges related to new excipients, context sensitive risk-benefit analysis).

Biochemical tolerance during low dose propylene glycol exposure in neonates: A formulation-controlled evaluation

Background and purpose of the study

Propylene glycol (PG) is a frequently co-administered solvent in formulations administered to neonates, but reports on its (in)tolerance are limited. We aimed to report on renal, metabolic and hepatic tolerance before, during and following intravenous (iv) PG-paracetamol exposure and compared these data with similar datasets reported in literature on neonates exposed to PG without paracetamol or paracetamol without PG.

Methods

Renal (diuresis, creatinemia, sodium), metabolic (Base Excess, Anion Gap, lactate, bicarbonate) and hepatic (liver enzymes, bilirubinemia) indicators before, during and following iv paracetamol-PG exposure in neonates as included in the PARANEO (paracetamol in neonates) study (intra-individual trends, ANOVA) were collected and analysed. Comparison with observations collected in cases exposed to either iv phenobarbital-PG or iv paracetamol-mannitol (inter-individual comparison, Mann Whitney-U test) were made.

Results

PG exposure (median 34.1 mg/kg/24 h) did not affect postnatal renal, metabolic and hepatic adaptations in 60 cases exposed to paracetamol-PG. These indicators were similar when compared to 29 cases exposed to phenobarbital-PG or 172 cases exposed to paracetamol-mannitol.

Major conclusion

Based on observations in 89 neonates, low dose PG exposure was tolerated well. Studies on PG pharmacokinetics and its covariates are needed to estimate the upper level of PG tolerance in neonates.

The propylene glycol research project to illustrate the feasibility and difficulties to study toxicokinetics in neonates

This paper aims to describe our propylene glycol (PG) research project to illustrate the feasibility and the difficulties encountered to perform excipient studies in neonates. PG is frequently co-administered excipient. PG accumulation potentially results in hyperosmolarity, lactic acidosis or hepato-renal toxicity in adults, reflecting issues related to pharmacokinetics (PKs) and -dynamics (PDs). Consequently, similar observations in neonates are urgently needed. Since newborns display 'physiological' impaired hepatic and renal elimination capacity, description of PG PK in neonates is warranted. The PG PD was assessed based on indicators of renal, hepatic and metabolic (in)tolerance earlier reported in adults and relating to osmolar changes. Based on the PK and PD data collected in neonates, we suggest that there is a lower limit of PG tolerance in neonates. In addition to preliminary data on PG disposition and tolerance in neonates, we mainly focus on the limitations of the current observations and the difficulties encountered during this PG project to further illustrate the specific setting of neonatal research.