A brief introductory video explaining Micropore's unique membrane-based system

Watch a video about our unique technology

Our Unique Technology

Contact Us


Scientific Papers

Welcome to our library of scientific papers relating to the science of membrane emulsification and encapsulation. Use our website site search tool to help locate papers relating to a specific research aspects.

Manufacturing nearly monodispersed complex coacervate microcapsules by membrane emulsification and spray drying

D. Miramontes Subillaga, S. Heinert, J. Weissbrodt, M. Dragosavac

Complex coacervation is a phase separation process in which two oppositely charged polymers or macromolecules in a solution come together at the liquid-liquid interface to form a dense coacervate shell. The process can be employed to encapsulate oil droplets, creating stable microcapsules that protect and control the release of oil while achieving a high encapsulation efficiency of active ingredients. In this work dry coacervate microcapsules of different size and shell thickness were manufactured combining a continuous single pass cross-flow membrane emulsification system and spray drying to obtain a dry powder. A single-pass crossflow membrane emulsification system with a single cylindrical 10 × 100 mm membrane module with 10 μm pore produced emulsion droplets between 71 μm and 114 μm with a dispersed phase (oil content) in the final emulsion between 3.3 and 6.2 vol/vol% and a total emulsion output mass rate between 25.68 kg h−1 – 49.68 kg h−1. Emulsions manufactured by membrane emulsification were nearly monodispersed with the highest span not exceeding 0.68. Addition of maltodextrin to the emulsion prior to spray drying increased the viscosity and prevented the capsules breakage. Microcapsules up to a mean droplet diameter of 113.19 ± 0.81 μm preserved the shell and had a yield up to 78.43 ± 0.97 wt%, a surface oil as low as 9.35 ± 0.88 wt% and an encapsulation efficiency of 71.09 ± 0.87 wt%.

Preparation of liposomes: a novel application of microengineered membranes: From laboratory scale to large scale

Laouini, A, Charcosset, C, Fessi, H, Holdich, RG, Vladisavljevic, GT (2013) Preparation of liposomes: a novel application of microengineered membranes: From laboratory scale to large scale, Colloids and Surfaces B: Biointerfaces, 112, pp.272-278, DOI: 10.1016/j.colsurfb.2013.07.066.

A novel ethanol injection method using microengineered nickel membrane was employed to produce POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) and Lipoid® E80 liposomes at different production scales. A stirred cell device was used to produce 73 ml of the liposomal suspension and the product volume was then increased by a factor of 8 at the same transmembrane flux (140 l m−2 h−1), volume ratio of the aqueous to organic phase (4.5) and peak shear stress on the membrane surface (2.7 Pa). Two different strategies for shear control on the membrane surface have been used in the scaled-up versions of the process: a cross flow recirculation of the aqueous phase across the membrane surface and low frequency oscillation of the membrane surface (∼40 Hz) in a direction normal to the flow of the injected organic phase. Using the same membrane with a pore size of 5 μm and pore spacing of 200 μm in all devices, the size of the POPC liposomes produced in all three membrane systems was highly consistent (80–86 nm) and the coefficient of variation ranged between 26 and 36%. The smallest and most uniform liposomal nanoparticles were produced in a novel oscillating membrane system. The mean vesicle size increased with increasing the pore size of the membrane and the injection time. An increase in the vesicle size over time was caused by deposition of newly formed phospholipid fragments onto the surface of the vesicles already formed in the suspension and this increase was most pronounced for the cross flow system, due to long recirculation time. The final vesicle size in all membrane systems was suitable for their use as drug carriers in pharmaceutical formulations.

Membrane Emulsification Process as a Method for Obtaining Molecularly Imprinted Polymers

Joanna Wolska and Nasim Jalilnejad Falizi

The membrane emulsification process (ME) using a metallic membrane was the first stage for preparing a spherical and monodisperse thermoresponsive molecularly imprinted polymer (TSMIP). In the second step of the preparation, after the ME process, the emulsion of monomers was then polymerized. Additionally, the synthesized TSMIP was fabricated using as a functional monomer N-isopropylacrylamide, which is thermosensitive. This special type of polymer was obtained for the recognition and determination of trace bisphenol A (BPA) in aqueous media. Two types of molecularly imprinted polymers (MIPs) were synthesized using amounts of BPA of 5 wt.%(MIP-2) and 7 wt.% (MIP-1) in the reaction mixtures. Additionally, a non-imprinted polymer (NIP) was also synthesized. Polymer MIP-2 showed thermocontrolled recognition for imprinted molecules and a higher binding capacity than its corresponding non-imprinted polymer and higher than other molecularly imprinted polymer (MIP-1). The best condition for the sorption process was at a temperature of 35 ◦C, that is, at a temperature close to the phase transition value for poly(N-isopropylacrylamide). Under these conditions, the highest levels of BPA removal from water were achieved and the highest adsorption capacity of MIP-2 was about 0.5 mmol g−1 (about 114.1 mg g−1) and was approximately 20% higher than for MIP-1 and NIP. It was also observed that during the kinetic studies, under these temperature conditions, MIP-2 sorbed BPA faster and with greater efficiency than its non-imprinted analogue.

Fast, Controlled, and Consistent: An Exploration of Current mRNA Vaccine Production Technologies

Jennifer Huen PhD, Beagle Scientific Inc.

When the first liposome-based drug, Doxil®, was approved in the mid-1990s, decades of research spurred the need for more suitable lipid formulations with faster, better controlled and more efficient manufacturing methods. Most recently, the urgency of the COVID19 pandemic pushed the scientific community for larger scale production of the mRNA vaccines with greater consistency—a need that is still evolving. Each of the current methods for industrial production of lipid nanoparticle (LNP) drugs have their unique set of pros and cons. Most liposome drugs are produced by lipid hydration and extrusion, a bulk method that is not suitable for consistent production of LNPs small enough to penetrate tissues for cell entry. From a formulation discovery perspective, microfluidic mixers can quickly produce large LNP libraries while minimizing waste. Yet these mixers cannot accommodate commercial-scale production volumes. Impingement jet mixing (IJM) is the most widespread manufacturing method as it can support high yields through unit parallelization but is less controllable and can potentially compromise LNP stability. Finally, advanced crossflow is a scalable, high efficiency method that has the potential to meet the demands of global disease emergencies. While IJM is currently the method of choice for mRNA vaccine manufacturers, other strategies must not yet be ruled out. As the development of new drug modalities and innovations accelerates, so too must strategies for faster, scalable drug manufacturing.

Need a formulation challenge solved? Ask a Micropore expert

At Micropore we enjoy working in partnership with our clients to solve formulation challenges and deliver the highest performing, most sustainable, most cost-effective formulated delivery systems.

Ask an expert

Stay Informed

Keep up to date with innovations at Micropore. Sign up today to stay informed with innovations at Micropore and automatically receive the Micropore newsletter and webinar invites.

Download the latest edition of the Micropore newsletter

Alternatively, you can download the latest edition of the Micropore newsletter HERE.