Nanoprecipitation preparation of low temperature-sensitive magnetoliposomes

Lysolipid-containing thermosensitive liposomes (LTSL) have gained attention for triggered release of chemotherapeutics. Superparamagnetic iron oxide nanoparticles (SPION) offers multimodal imaging and hyperthermia therapy opportunities as a promising theranostic agent. Combining LTSL with SPION may further enhance their performance and functionality of LTSL. However, a major challenge in clinical translation of nanomedicine is the poor scalability and complexity of their preparation process. Exploiting the nature of self-assembly, nanoprecipitation is a simple and scalable technique for preparing liposomes. Herein, we developed a novel SPION-incorporated lysolipid-containing thermosensitive liposome (mLTSL10) formulation using nanoprecipitation. The formulation and processing parameters were carefully designed to ensure high reproducibility and stability of mLTSL10. The effect of solvent, aqueous-to-organic volume ratio, SPION concentration on the mLTSL10 size and dispersity was investigated. mLTSL10 were successfully prepared with a small size (∼100 nm), phase transition temperature at around 42 °C, and high doxorubicin encapsulation efficiency. Indifferent from blank LTSL, we demonstrated that mLTSL10 combining the functionality of both LTSL and SPION can be successfully prepared using a scalable nanoprecipitation approach.

Fabrication of poly-sulfosalicylic acid film decorated pure carbon fiber as electrochemical sensing platform for detection of theophylline

In this work, we integrated the superiority of good conductivity, large surface area of carbon fibers and the catalytic property, good biocompatibility of polymer sulfosalicylic acid to construct a novel electrochemical sensor to detect theophylline in drug analysis. The morphology of nanocomposite was characterized by scanning electron microscopy (SEM). The polymerization between monomers was observed by Fourier transform infrared spectroscopy (FTIR). The composite between carbon material and polymer was verified by Raman spectrum. Under the optimal experimental conditions, the concentration of theophylline (0.6∼137 μM) and the peak current value revealed a good linear relationship and the limit of detection as low as 0.2 μM. In addition, the proposed sensor exhibits repeatability, stability and ease of selectivity.

A high-throughput system combining microfluidic hydrogel droplets with deep learning for screening the antisolvent-crystallization conditions of active pharmaceutical ingredients

Crystallization of active pharmaceutical ingredients (APIs) is a crucial process in the pharmaceutical industry due to its great impact in drug efficacy. However, conventional approaches for screening the optimal crystallization conditions of APIs are usually time-consuming, labor-intensive and expensive. Recently, droplet microfluidic technology has offered an alternative strategy for high-throughput screening of crystallization conditions. Despite its many advantages such as low sample consumption, reduced operation time, increased throughput, etc., some challenges remain to be solved, such as instability of droplets in the long-term and tedious efforts required for extracting useful information from massive data. To solve these problems, a high-throughput system that combined microfluidic hydrogel droplets with deep learning was proposed for the first time to screen the antisolvent-crystallization conditions of APIs. In this system, stable hydrogel droplets containing different concentrations of indomethacin, its solvent and antisolvent were generated on a chip. Crystals of indomethacin with different morphologies were formed in hydrogel droplets, and their optical images were captured by a camera. Then, deep learning was applied to identify the hundreds of indomethacin crystal images and successfully classify the crystal morphologies in a short time; a ternary phase diagram was drawn by combining the experimental results with the recognition results of crystal morphologies, and was used to guide the scale-up preparations of indomethacin crystals as desired. This system, which integrated high throughput preparation, characterization and data analysis, is also useful for screening the crystallization conditions and processes of semiconductors, catalysts, agrochemicals, proteins and other specialty chemicals.

A high-throughput multi-microfluidic crystal generator (MMicroCryGen) platform for facile screening of polymorphism and crystal morphology for pharmaceutical compounds

In this work, a novel multi-microfluidic crystallization platform called MMicroCryGen is presented, offering a facile methodology for generating individual crystals for fast and easy screening of the polymorphism and crystal habit of solid compounds. The MMicroCryGen device is capable of performing 8 × 10 cooling crystallization experiments in parallel using 8 disposable microcapillary film strips, each requiring less than 25 μL of solution. Compared to traditional microfluidic systems, the MMicroCryGen platform does not require complex fluid handling; it can be directly integrated with a 96-well microplate and it can also work in a "dipstick" mode. The produced crystals can be safely and directly observed inside the capillaries by optical and spectroscopic techniques. The platform was validated by performing a number of independent experimental runs for: (1) polymorph and hydrate screening of ortho-aminobenzoic acid, succinic acid and piroxicam; (2) co-crystal form screening of the p-toluenesulfonamide/triphenylphosphine oxide system; (3) studying the effect of o-toluic acid on ortho-aminobenzoic cooling crystallization (effect of structurally related additives). In all three cases, all known solid forms were identified with a single experiment using ∼200 μL of solvent and just a few micrograms of the solid material. The MMicroCryGen is simple to use, inexpensive and it provides increased flexibility compared to traditional crystallization techniques, being an effective new microfluidic solution for solid form screening in pharmaceutical, fine chemicals, food and agrochemical industries.

Pharmaceutical cocrystallization techniques. Advances and challenges

Cocrystals are homogenous (single-phase) crystalline structures composed by two or more components in a definite stoichiometric ratio bonded together by noncovalent bonds. Pharmaceutical industry has been showing interest in cocrystals due to their ability to improve active pharmaceutical ingredients (API's) properties, such as solubility, dissolution, bioavailability, stability and processability. The necessity for high-throughput screening methods and methods capable of producing cocrystals in an industrial scale still hinders the use of cocrystals by the pharmaceutical industry. The aim of this review is to present an extensive overview of the cocrystallization methods, focusing in the specificities of each technique, its advantages and disadvantages. The review is divided into solvent-based and solvent-free methods. The most appropriate methods to the different stages of cocrystals manufacture, from the screening phase to industrial production are identified. The use of continuous and scalable methods in cocrystal production as well as the implementation of quality-by-design and process analytical technology concepts are also addressed.

Progress of crystallization in microfluidic devices

Microfluidic technology provides a unique environment for the investigation of crystallization processes at the nano or meso scale. The convenient operation and precise control of process parameters, at these scales of operation enabled by microfluidic devices, are attracting significant and increasing attention in the field of crystallization. In this paper, developments and applications of microfluidics in crystallization research including: crystal nucleation and growth, polymorph and cocrystal screening, preparation of nanocrystals, solubility and metastable zone determination, are summarized and discussed. The materials used in the construction and the structure of these microfluidic devices are also summarized and methods for measuring and modelling crystal nucleation and growth process as well as the enabling analytical methods are also briefly introduced. The low material consumption, high efficiency and precision of microfluidic crystallizations are of particular significance for active pharmaceutical ingredients, proteins, fine chemicals, and nanocrystals. Therefore, it is increasingly adopted as a mainstream technology in crystallization research and development.

Interplay between materials and microfluidics

Developments in the field of microfluidics have triggered technological revolutions in many disciplines, including chemical synthesis, electronics, diagnostics, single-cell analysis, micro- and nanofabrication, and pharmaceutics. In many of these areas, rapid growth is driven by the increasing synergy between fundamental materials development and new microfluidic capabilities. In this Review, we critically evaluate both how recent advances in materials fabrication have expanded the frontiers of microfluidic platforms and how the improved microfluidic capabilities are, in turn, furthering materials design. We discuss how various inorganic and organic materials enable the fabrication of systems with advanced mechanical, optical, chemical, electrical and biointerfacial properties - in particular, when these materials are combined into new hybrids and modular configurations. The increasing sophistication of microfluidic techniques has also expanded the range of resources available for the fabrication of new materials, including particles and fibres with specific functionalities, 3D (bio)printed composites and organoids. Together, these advances lead to complex, multifunctional systems, which have many interesting potential applications, especially in the biomedical and bioengineering domains. Future exploration of the interactions between materials science and microfluidics will continue to enrich the diversity of applications across engineering as well as the physical and biomedical sciences.