Micro-Flow Imaging

Method Introduction

Micro-flow imaging (MFI) – officially called flow imaging microscopy (FIM) or dynamic imaging analysis (DIA) – is a well-established and frequently used technique for sizing, quantifying, visualizing, and, in some instances, identifying (sub-) visible particles. In MFI, bright-field images are captured in successive frames as a continuous sample stream passes through a flow cell positioned in the field of view of a microscopic system. The digital images of the particles in the sample are processed by image morphology analysis software that allows their quantification in size and count.

Coriolis operates several systems from suppliers, such as Micro-Flow Imaging, devices from ProteinSimple, and FlowCam systems from Fluid Imaging Technology. These instruments typically cover a size range from 1 to 200 µm or 1 to 400 µm respectively, while the upper particle concentration limit generally is higher than light obscuration systems. Besides enumerating the subvisible particles present in the sample, flow imaging microscopy provides information about particle morphology for particles larger than about 3-4 µm. This capability marks an inherent advantage of MFI over many other particle characterization techniques, as it may allow the identification of substances commonly present in biopharmaceuticals, such as silicone oil droplets.

Applications

MFI has become an established technique for subvisible particle analysis, though no monograph/specifications in the pharmacopeias exist. The instructional chapter USP<1787> mentions MFI as a possible orthogonal technique for subvisible particle analysis in addition to light obscuration. Even though MFI is also a light-based technique, it is typically superior to light obscuration in detecting particles with a refractive index close to the surrounding formulation.

MFI is primarily used as a research tool but has gained importance, for example, during troubleshooting to characterize further or identify subvisible particles detected by light obscuration. The technique also identifies silicone oil-like droplets in prefilled syringes or double-chamber cartridges. At Coriolis, MFI can be offered in full GMP compliance for, e.g., lot release testing.

Quality and Biosafety Level

We provide all our analytical services with the highest quality standards. Experienced scientists carry out each project, and a scientific reviewer comprehensively checks every report or data presentation.

We offer this technology with the following quality and biosafety levels:

Up to GMP Level

This method is available under GMP in dedicated labs with qualified equipment and full QA involvement.

Up to biosafety level 1

This method can be applied to proteins, nucleic acids, and most viral vectors, including AAVs and more.

Analytical Method Development, Qualification and Validation

For common sample types, we can often apply standardized methods with little setup effort. However, when needed, our experienced analytical experts create or optimize custom methods tailored to your active pharmaceutical ingredient, product type and development phase.

Method Development

Our method development approach tailors sample preparation, method settings and data analysis to the needs of your project and sample.

We include representative samples and, where available, suitable reference standards and stressed/degraded materials, allowing our analytical scientists to design a highly suitable, stability-indicating, robust and repeatable method. Upon request, we will compile a detailed description of the method for your records.

Method Qualification

Method qualification is the initial assessment of an analytical procedure’s performance to show its suitability for its intended purpose.

During method qualification, our analytical scientists perform documented testing demonstrating that the analytical procedure meets criteria in several categories. Criteria may include factors such as repeatability, specificity and robustness. We compile a qualification plan and report, including all relevant data.

Method Validation

Under GMP conditions, method validation confirms that an analytical procedure’s performance suits its intended purpose. Depending on the method’s scope, a broad range of method characteristics, such as specificity, accuracy, precision, limit of detection/limit of quantification (LOD/LOQ), linearity and range, is considered.

During method validation, our analytical scientists perform documented testing demonstrating that the analytical procedure consistently produces a result that meets the predetermined acceptance criteria. We compile a validation plan and report that includes all relevant data.

Depending on the development phase, a fit-for-purpose validation approach can be offered, adjusting the validation required efforts in a phase-appropriate way to meet the method’s needs.

Method Verification

Compendial method verification confirms that a compendial method (e.g., from Ph. Eur. or USP) is suitable and reliable for its intended purpose under the specific conditions of the laboratory.

Unlike full method validation, compendial method verification is often considered a partial validation since the method has already undergone extensive testing and validation during its inclusion in the compendium. The extent of method verification depends on the type of method.

During method verification, our analytical scientists perform documented testing demonstrating that the developed analytical method performs adequately for the specific product or matrix being tested and within the specific laboratory where the method will be employed.

Talk to Our Experts or Request a Quote

Our expert team is ready to answer your questions and guide you to the services best suited to your program’s modality, stage and challenge. If your needs are well-defined, we’ll begin the quotation process.

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