Resonant Mass Measurement

Method Introduction

Resonant Mass Measurement (RMM), also known as suspended microchannel resonator (SMR), is a valuable technique for sizing and quantifying particles.

RMM analysis is based on the Archimedes principle: The upward buoyant force acting on an object in a fluid equals the weight of the fluid displaced by the object. The sample solution flows through a microchannel inside a resonating cantilever, which resonates mechanically. When a particle passes the embedded channel, the resonation frequency will change proportionally to the particle’s buoyant mass. Positively buoyant and negatively buoyant particles can be discriminated as they increase or decrease the frequency of the cantilever. The buoyant mass is then converted into mass and finally into size based on the particle’s and fluid’s densities. The system can automatically determine the latter.

Applications

RMM is applicable for particles with a size from about 300 nm to 4 µm, depending on the density difference between particles and fluid. The upper particle concentration limit is roughly 10^7 particles/mL and is method- and sample-dependent.

One of the main applications for RMM is the quantitative discrimination between silicone oil droplets and protein particles. Such data are crucial for prefilled syringes and cartridges in any development phase since silicone oil (coated on the glass surface for plunger lubrication) can be present in the product as submicron or micrometer droplets. The differentiation is unambiguous, provided no other particle type is present in the sample.

RMM is also a valuable orthogonal tool for other particle analytics. Its light-independent measurement principle makes the technique robust against detection issues related to a particle’s refractive index, which is well known for light-based techniques, such as light obscuration (LO) and flow imaging microscopy (FIM) and, to some extent, also for light scattering-based techniques, such as dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA).

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:

R&D level

We offer this method under R&D. Our GRP system assures the highest-quality research standards.

Up to biosafety level 2

This method can be applied to nucleic acids, viruses, cells, viral vectors, including lentiviruses, 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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