A methodology for the sustainability evaluation of industrial pharmaceutical processes

This work develops and extends a general framework for the prediction of industrial sustainability (Process Sustainability Prediction Framework PSP [1]) implementing features for treating the sustainability prediction for batch pharmaceutical processes. The framework is based on the implementation of the simulation of batch processes, typical of the pharmaceutical and biotech industry, coupled with the PSP algorithm [2]. The resulting procedure allows performing evaluation of different industrial batch plants alternatives using representative indicators or metrics that cover the three aspects of sustainability: economy, environment and society Two kinds of sustainability indicators are used in the present work: (i) three-dimensional indicators (3D-indicators) and (ii) one-dimensional indicators (1D-indicators). The methodology proposed by Martins [3], containing 3D-indicators, has been extended including the concept of time, related to discontinuous processes such as the pharmaceutical ones. This modified methodology is then used in this framework as a first evaluation of the global sustainability of the process under study. The methodology takes into account the material intensity (the amount of nonrenewable resources required to obtain a unit mass of products), the energy intensity (the energy demands of the process), the potential environmental impact (the emissions and discharges of hazardous chemicals to the environment) and the potential chemical risk (the risk associated with the manipulation, storage and use of hazardous chemical substances). The latter has been modified considering the cycle time of batch reactors. The 3D-indicators are calculated using the results obtained from process simulation coupled with the toxicological database included in the framework. In the case a more sophisticated evaluation of the impact is needed, one may resort to the evaluation of 2D and 1D-indicators. One relevant 1D indicator is the Waste Reduction Algorithm (WAR) [4,5]: this algorithm has been modified to include the time of charge, reaction and discharge of chemicals from reactor and the introduction of new substances for rinsing, which is a more common operation in discontinuous processes than in continuous ones. In PSP the algorithm is implemented in a CAPE OPEN standard methodology which is able to interact with most process simulators software available on the market. In this perspective, PSP Framework has been extended to treat also batch processes, thus extending the possibility of performing process sustainability predictions to pharma and biotech production processes. Process data are extracted from process simulation software, coupled with toxicological data and fed to the PSP algorithm for the determination of sustainability indicators. A CAPE OPEN code has been developed and examples are reported of application of PSP to batch processes simulated with AspenPlus.