Tobramycin

Detailed information

General information about assessment reports

Since 2006, an Environmental Risk Assessment (ERA) for the active pharmaceutical substance shall accompany an application for a marketing authorisation in EU for a medicinal product for human use. Parts of environmental data are available in the public assessment report (PAR/EPAR for centrally approved medicines). Environmental considerations are not included in the benefit-risk assessment for human medicines. If new data emerge after approval that necessitate an update of the environmental risk assessment, a variation application (“type IB C.I.z variation”) must be submitted to the regulatory authority.

The PEC (predicted environmental concentration) values used to calculate risk in the manufacturers' assessment reports are based on the estimated use of the medicinal product to which the assessment report relates, as well as possibly other products from the same company, not all medicinal products containing the same active substance.

Assessment report Tobi Podhaler

Assessment report for Tobi Podhaler (tobramycin), Novartis Europharm, 2011-08-25.

Hazard

Persistence: The adsorption–desorption study (OECD 106) showed very high Koc values (48,945–115,185 L/kg in sludge and 90,445–657,429 L/kg in soil). The OECD 301 test showed that the substance was not readily biodegradable, and no OECD 308 study on transformation in aquatic sediment systems was performed. The applicant had performed a phase IIa assessment and submitted the studies, but the results had no impact since the evaluation stopped at phase I. Therefore, despite tobramycin not being readily biodegradable, an OECD 308 study was not required, nor was an environmental risk assessment for the terrestrial compartment necessary even though the Koc exceeded 10,000 L/kg.

Bioaccumulation: Log K_ow -5.8.

Toxicity: There are data for 3 trophic levels, most sensitive algae NOEC 51 microg/L.

Risk

The risk, PEC/PNEC, calculated from data in the assessment report from a European perspective:

PEC = 0.007 microg/L.

PNEC = Lowest NOEC, 51 microg/L/10 (Assessment Factor (AF) for 3 chronic studies) = 5.1 microg/L

PEC/PNEC = 0.00137 which gives the risk insignificant.

Assessment report Tobramycin PARI

Assessment report for Tobramycin PARI, PARI Pharma GmbH, 13 December 2018,
EMA/901707/2018.

Hazard

Persistence: No data.

Bioaccumulation: Log K_ow -5.8.

Toxicity: No data.

Risk

The risk, PEC/PNEC, calculated from data in the assessment report from a European perspective:

PEC = 0.0067 microg/L.

Comment on the fact that only a phase I study is available

Tobramycin has only undergone a phase I study in accordance with regulatory requirements for environmental risk assessments (Guideline on the environmental risk assessment of medicinal products for human use, EMEA/CHMP/SWP/4447/00 Rev. 1- Corr.) A phase I study includes data on bioaccumulation and an estimation of the environmental concentration of tobramycin (PEC_{Surface water}). If the specified threshold values are not exceeded, the company is not required to conduct a Phase II study, which includes data on toxicity, persistence, and risk assessment based on PEC/PNEC.

Fass environmental information

Fass environmental information for Tobrasone (tobramycin) from Novartis (retrieved on 2026-01-20).

Excretion (metabolism)

Tobramycin is not metabolized and is primarily excreted unchanged in the urine.

Hazard

Persistence: Biotic degradation: In the OECD 301B test, 0% degradation was observed after 28 days, indicating that tobramycin is not readily biodegradable (NOTOX Project 488776). As the criteria for ready degradability were not met, the phrase “Tobramycin is potentially persistent” was selected.

Bioaccumulation: Log P = -5.8 (method unknown).

Toxicity: There are data for 3 trophic levels, most sensitive algae NOEC 51 microg/L.

Risk

PEC/PNEC is based on sales data in Sweden in year 2021.

PEC = 0.00144 microg/L.

PNEC = Lowest NOEC, 51 microg/L/10 (Assessment Factor (AF) for 3 chronic studies) = 5.1 microg/L.

PEC/PNEC = 0.000282 which gives the risk insignificant.