Rapid scale-up and production of active-loaded PEGylated liposomes

Abstract

Manufacturing of liposomal nanomedicines (e.g. Doxil®/Caelyx®) is a challenging and slow process based on multiple-vessel and batch processing techniques. As a result, the translation of these nanomedicines from bench to bedside has been limited. Microfluidic-based manufacturing offers the opportunity to address this issue, and de-risk the wider adoption of nanomedicines. Here we demonstrate the applicability of microfluidics for continuous manufacturing of PEGylated liposomes encapsulating ammonium sulfate (250 mM). Doxorubicin was subsequently active-loaded into these pre-formed liposomes. Critical process parameters and material considerations demonstrated to influence the liposomal product attributes included solvent selection and lipid concentration, flow rate ratio, and temperature and duration used for drug loading. However, the total flow rate did not affect the liposome product characteristics, allowing high production speeds to be adopted. The final liposomal product comprised of 80 -100 nm vesicles (PDI <0.2) encapsulating ≥ 90% doxorubicin, with matching release profiles to the innovator product and is stable for at least 6 months. Additionally, vincristine and acridine orange were active-loaded into these PEGylated liposomes (≥ 90% and ˜100 nm in size) using the same process. These results demonstrate the ability to produce active-loaded PEGylated liposomes with high encapsulation efficiencies and particle sizes which support tumour targeting.

Manufacturing Considerations for the Development of Lipid Nanoparticles Using Microfluidics

“…In general, optimal parameters consist of convenient particle size (usually below 100 nm to allow for sterile filtration and effective nucleic acid delivery), adequate composition, high encapsulation efficiencies (>90%), stability upon storage and a reproducible and scalable manufacturing method. Microfluidics has previously been shown to be an effective tool for the manufacture of LNPs [15,16,19,20], liposomes [21][22][23] and polymer-based nanoparticles [24][25][26]. However, the literature lacks reports evaluating the effects of the formulation and microfluidic operating parameters on the physicochemical characteristics of the LNPs.…”

“…Therefore, we hypothesize that the reduced mixing within the microfluidic micromixer at 5 mL/min results in a slow dilution of the solvent, promoting the formation of larger particles. On the other hand, the effect of the FRR on vesicle physicochemical characteristics has been extensively reported [14,22,23,28]. In general, increasing the FRR, and therefore, increasing polarity, creates a narrow organic solvent stream, which aids the formations of smaller particles due to reduced particle fusion [11].…”

“…The aim of this experiment was to assess if minimal and large modifications on the molar lipid content could be detected by the physicochemical characteristics of the formed particles. Process analytical techniques such as AT-line sizers could be implemented in the manufacture process and therefore, this would allow for the quick detection of deviations in LNP composition if large production of LNPs is required [23]. LNPs generally require four components: a phospholipid, cholesterol, a permanent cationic or ionisable lipid and a PEG-lipid.…”

Preparation, Characterization, and Biodistribution of Glutathione PEGylated Nanoliposomal Doxorubicin for Brain Drug Delivery with A Post-insertion Approach

“…The pre-admixture of contents was prepared on the same day of the in vivo experiments to ensure a fresh, more stable, and consistent formula with a higher encapsulation e ciency is injected. The active components including the market available Caelyx and lyophilized GSH-PEG were mixed, measured, and linked immediately before drug administrations [81][82][83][84].…”

Recent Advances in Lipid-Based Drug Delivery

“…Further, microfluidics technology combined with ethanol injection is a promising approach that improves reproducibility. The scalability of microfluidic devices can be improved by increasing the total flow rate [ 2 ]. The use of millireactors also improves scalability [ 3 ].…”