Bottom-up production of injectable itraconazole suspensions using membrane technology.

Bottom-up production of active pharmaceutical ingredient (API) crystal suspensions offers advantages in surface property control and operational ease over top-down methods. However, downstream separation and concentration pose challenges. This proof-of-concept study explores membrane diafiltration as a comprehensive solution for downstream processing of API crystal suspensions produced via anti-solvent crystallization. It involves switching the residual solvent (N-methyl-2-pyrrolidone, NMP) with water, adjusting the excipient (d-α-Tocopherol polyethylene glycol 1000 succinate, TPGS) quantity, and enhancing API loading (solid concentration) in itraconazole crystal suspensions. NMP concentration was decreased from 9 wt% to below 0.05 wt% (in compliance with European Medicine Agency guidelines), while the TPGS concentration was decreased from 0.475 wt% to 0.07 wt%. This reduced the TPGS-to-itraconazole ratio from 1:2 to less than 1:50 and raised the itraconazole loading from 1 wt% to 35.6 wt%. Importantly, these changes did not adversely affect the itraconazole crystal stability in suspension. This study presents membrane diafiltration as a one-step solution to address downstream challenges in bottom-up API crystal suspension production. These findings contribute to optimizing pharmaceutical manufacturing processes and hold promise for advancing the development of long-acting API crystal suspensions via bottom-up production techniques at a commercial scale.

Tailoring the use of excipients in bottom-up production of naproxen crystal suspensions via membrane technology.

Long-acting crystal suspensions of active pharmaceutical ingredients (API) mostly comprised of an API, a suspension media (water) and excipients and provide sustained API release over time. Excipients are crucial for controlling particle size and to achieve the stability of the API crystals in suspension. A bottom-up process was designed to produce long-acting crystal suspensions whilst investigating the excipient requirements during the production process and the subsequent storage. PVP K30 emerged as the most effective excipient for generating stable naproxen crystals with the desired size of 1 to 15 µm, using ethanol as solvent and water as anti-solvent. Calculations, performed based on the crystal properties and assuming complete PVP K30 adsorption on the crystal surface, revealed lower PVP K30 requirements during storage compared to initial crystal generation. Consequently, a membrane-based diafiltration process was used to determine and fine-tune PVP K30 concentration in the suspension post-crystallization. A seven-stage diafiltration process removed 98 % of the PVP K30 present in the suspension thereby reducing the PVP-to-naproxen ratio from 1:2 to 1:39 without impacting the stability of naproxen crystals in suspension. This work provides insights into the excipient requirements at various production stages and introduce the membrane-based diafiltration for precise excipient control after crystallization.

A systematic evaluation of the resource consumption of active pharmaceutical ingredient production at three different levels.

In this paper, the development and the advantages of a methodology which allows the systematic assessment of the environmental impact on the resource side of specific pharmaceutical production processes with limited data entry is presented. The quantification of the process-specific mass and energy balances over three different system boundaries (process, gate-to-gate, and cradle-to-gate) is based on the methodology explained in Van der Vorst et al. (Ind. Eng. Chem. Res.2009, 48(11), 5344-5350). These mass and energy balances are now coupled with the thermodynamic term exergy allowing the quantification of the resource efficiency at the process and gate-to-gate level and the environmental impact at the cradle-to-gate level. The advantages of such a calculation tool for the resource evaluation are illustrated with five consecutive pharmaceutical production steps which are part of the galantamine (anti-Alzheimer medication) pathway. It is shown that such a quantitative and systematic evaluation tool allows a detailed and relatively fast evaluation of the resource efficiency of active pharmaceutical ingredient (API) production processes at the three different levels. Combining thermodynamics and the systematic data inventory methodology for the quantification of the resource efficiency first allows results to be merged into a single impact value (exergy loss/mol API or CEENE/mol API) for fast benchmarking and evaluation of different API production processes. Second, it also allows results to be divided over different categories depending on the users' interest and make thorough analysis of processes in order to pinpoint process improvements and quantitatively justify the introduction of second generation production processes or production techniques.