Scoping review to identify data needs and environmental hotspots for future LCA Studies: Insights into pharmaceutical excipients and processes

• Scoping reviews can complement Life Cycle Assessments in environmental assessments • The availability of environmental data for pharmaceuticals is increasing, but the field is dominated by disciplines other than pharmacy • There may be environmental issues associated with common excipients regarded as safe • There is a lack of environmental metrics for pharmaceutical manufacturing processes and excipients • Environmental assessments of pharmaceuticals lack uniformity, making comparisons difficult In recent years, the environmental assessment and optimization of pharmaceutical dosage forms have received increasing attention. Consequently, interest in Life Cycle Assessments (LCA) has grown, and LCA is rapidly becoming the standard method of environmental evaluations across many industries, including the pharmaceutical sector. LCA is, however, a high entry barrier method requiring expertise, software- and database access, and process specific experimentally obtained performance data (e.g. electricity consumption). In the context of pharmaceuticals, significant challenges arise due to the limited availability of input data. Because of these limitations, we wanted to investigate the feasibility of using a scoping review as an alternative to LCA for evaluating the environmental implications of pharmaceuticals. In this literature review, a total of 8788 articles were screened, of which 117 were relevant. The search was anchored in a formulation previously developed. In this formulation, 3.0 mm minitablets were manufactured by direct compression from a spray-dried amorphous solid dispersion of indomethacin in polyvinylpyrrolidone (PVP) or hydroxypropyl methylcellulose acetate succinate (HPMCAS) with the additional use of milled lactose monohydrate (LACT), microcrystalline cellulose (MCC) and magnesium stearate (MgSt) as tablet excipients. Through the systematic literature review, relevant environmental information was found for most of the processes and excipients investigated. Research currently undertaken at the intersection of environmental review and pharmaceutical manufacturing shows an upward trend. Most notably, recent research indicates that excipients generally regarded as safe (GRAS) may not necessarily be without environmental concern. Furthermore, excipients may be manufactured through multiple different routes which muddles the environmental comparison of different options. Still, this literature review identified a marked absence of sustainability-themed research specific to pharmaceutical manufacturing. With the issues uncovered, more research is sorely needed to provide guidance in formulation choices.