Vol 75 – Trends and Best Practices in Particle Size Analysis for Drug Products

August 02, 2023The Pathfinder 37 Min Read

Regulatory Trends and Best Practices in Particle Size Analysis for Drug Products 


Particle size analysis (PSA) is a pivotal analytical tool in the pharmaceutical industry, specifically in the development of drug products. It plays a significant role in various stages of the drug development process, from formulation design and manufacturing to the final product’s performance, efficacy, and safety. This article explores the trends and best practices in particle size analysis, underlining their relevance in the modern pharmaceutical landscape. 


The Rising Importance of Particle Size Analysis 


The significance of particle size and distribution in drug products is well-established, impacting crucial aspects such as dissolution rate, bioavailability, stability, and even the drug’s pharmacokinetics. However, recent advancements in pharmaceutical technology and regulatory demands have thrust PSA into the spotlight.  

One such advancement is the increasing trend towards nanotechnology and complex drug delivery systems like liposomes, nanoparticles, or emulsions. Such systems often rely on very specific particle size and size distribution to function as intended, making accurate PSA more important than ever. 


Trends in Particle Size Analysis 


Embracing Nanotechnology 

As mentioned, nanotechnology has become a prominent part of modern drug development. Novel techniques such as Nanoparticle Tracking Analysis (NTA) and Dynamic Light Scattering (DLS) are gaining popularity for analyzing nanoparticles’ size and distribution. These techniques offer greater sensitivity and precision for particles in the nanometer range, a necessary capability in this era of nanoparticle-based drug delivery systems.  

Automation and High Throughout  

The pharmaceutical industry is moving towards automation and high throughput systems to enhance productivity and minimize human error. Automated PSA instruments are now commonplace, delivering quick, reliable results, and allowing for more samples to be analyzed in less time.  

Incorporation of Advanced Analytical Techniques  

Advanced techniques such as laser diffraction and imaging methods are being increasingly adopted for particle size analysis. These techniques provide more comprehensive data, including particle shape and morphology, which can be crucial in some drug formulations. 


Expanding on Trends in Particle Size Analysis 


Nanoparticle Analysis 

As nanotechnology becomes increasingly prevalent in the pharmaceutical industry, the need for precise nanoparticle analysis has skyrocketed. Advanced techniques like Nanoparticle Tracking Analysis (NTA) and Dynamic Light Scattering (DLS) offer the required sensitivity for analyzing particles in the nanometer range.  


The push for efficiency and consistency has made automation a growing trend in particle size analysis. Automated PSA instruments can analyze multiple samples simultaneously, reducing human error and increasing throughput.  

Advanced Analytical Techniques 

The growing complexity of drug formulations necessitates more advanced analytical techniques. Techniques such as laser diffraction and imaging methods can provide more comprehensive data, including information on particle shape and morphology. 


Case Studies: Trends in Action 


Case Study 1: Nanoparticle Drug Delivery System 

A biotech firm was developing a nanoparticle-based drug delivery system for targeted cancer therapy. The therapeutic efficacy of this system depended heavily on the size of the nanoparticles, which needed to be within a specific range to achieve optimal tumor penetration and cellular uptake.  

To accurately measure the nanoparticle size, the company used Nanoparticle Tracking Analysis (NTA), a technique that can visualize and measure nanoparticles in liquids, and is highly sensitive to particles in the nanometer range. By leveraging this advanced technique, the company was able to confirm that their nanoparticles fell within the desired size range, supporting their efforts to develop an effective drug delivery system. 


Case Study 2: High Throughput Screening 

A large pharmaceutical company was conducting high throughput screening for drug discovery. The process involved the testing of thousands of compounds, each requiring particle size analysis.  

To manage this substantial workload, the company integrated automated particle size analyzers into their workflow. These instruments were capable of analyzing multiple samples simultaneously, significantly increasing the company’s throughput and reducing the time taken for the screening process. 


Case Study 3: Complex Drug Formulation 

A pharmaceutical company was developing a complex drug formulation that involved particles of various sizes and shapes. The performance of the drug was dependent on the size distribution and the shape of the particles.  

The company adopted an advanced technique, combining laser diffraction and imaging methods for their particle size analysis. This allowed them not only to measure the size distribution but also to obtain information on the shape and morphology of the particles. By leveraging these advanced analytical techniques, the company was able to gain a comprehensive understanding of their complex drug formulation.  

In all these cases, staying abreast of the latest trends in particle size analysis allowed these organizations to effectively tackle the challenges they faced in their drug development process. Whether it was dealing with nanoparticles, managing high throughput needs, or analyzing complex formulations, the right choice of analytical techniques proved crucial. 


Best Practices in Particle Size Analysis 


Method Development and Validation 

The development and validation of the method used for PSA is a key aspect to ensure accurate and reliable results. This process involves determining the most suitable analytical technique for the sample, optimizing the parameters for the analysis, and validating the method’s performance.  

Regular Instrument Calibration and Maintenance 

Regular calibration and maintenance of the PSA instrument are essential to maintaining accuracy and precision. This should be part of a standard operating procedure to ensure consistent and reliable results.  

Consideration of Sample Preparation 

Sample preparation is a critical step that can greatly impact the results of the PSA. The sample must be prepared in a way that is representative of the entire batch and does not change the particle size distribution.  

Proper Documentation 

All stages of the PSA, including method development, sample preparation, analysis, and data interpretation, should be thoroughly documented. This is vital for traceability, quality control, and regulatory compliance.  

As the pharmaceutical industry continues to evolve, particle size analysis remains a critical tool in drug development. Staying informed of the latest trends and adhering to best practices ensures that your organization is prepared to navigate the complex landscape of drug product development. 


Deeper Dive into Best Practices in Particle Size Analysis 


Selection of Suitable Analytical Technique 

The choice of analytical technique for PSA should be based on the nature of the drug product and the size range of the particles. Techniques like laser diffraction and sieving are suitable for larger particles, while techniques like Dynamic Light Scattering (DLS) and Nanoparticle Tracking Analysis (NTA) are more suitable for nanoparticles.  

Optimizing Analysis Parameters 

The parameters for the analysis should be optimized to ensure the most accurate results. This involves fine-tuning the settings of the instrument, such as the intensity of the light source, the angle of detection, or the measurement time, based on the characteristics of the sample.  

Rigorous Method Validation 

The method used for PSA should be validated to ensure its reliability. This involves assessing parameters such as accuracy, precision, specificity, linearity, range, and robustness, following guidelines such as ICH Q2(R1).  

Implementation of Quality Control Measures 

Quality control measures should be implemented to ensure the consistency of the PSA. This includes regular instrument calibration, the use of control charts, and the implementation of corrective actions when necessary. 


Case Studies: Best Practices in Action 


Case Study 1: Development of a Liposomal Drug Product 

In this case, a pharmaceutical company was developing a liposomal drug product, where the size of the liposomes was critical for the drug’s performance. The company chose to use Dynamic Light Scattering (DLS) for the particle size analysis due to its sensitivity to nanoparticles.  

The company optimized the DLS parameters, such as the measurement time and the refractive index of the sample, to get the most accurate results. The method was then validated, showing high accuracy, precision, and robustness. Regular calibration of the DLS instrument and the implementation of control charts ensured the consistency of the PSA throughout the drug development process. 


Case Study 2: Formulation of a Generic Drug with Micronized Active Ingredient 

A generic drug manufacturer was formulating a drug with a micronized active ingredient, where the particle size could significantly impact the drug’s bioavailability. The manufacturer chose to use laser diffraction for the PSA due to its suitability for micron-sized particles.  

The laser diffraction parameters were optimized based on the characteristics of the active ingredient, such as its refractive index and shape. The method was validated and showed excellent linearity, range, and specificity. Regular maintenance of the laser diffraction instrument and rigorous documentation of the PSA process ensured the reliability of the results and compliance with regulatory requirements.  

In both cases, adhering to best practices in particle size analysis was key to the successful development of the drug products. The choice of suitable analytical techniques, optimization and validation of the methods, and implementation of quality control measures ensured accurate, reliable, and consistent results. 


Regulatory Requirements for Particle Size Analysis 


Particle size analysis (PSA) in pharmaceuticals is regulated under a strict regulatory framework, primarily because the size and distribution of particles in a drug product can significantly impact its safety and efficacy. The relevant regulatory requirements encompass various aspects, from method validation to reporting of results. 


Method Validation 


The International Council for Harmonisation (ICH) guidelines, specifically the ICH Q2(R1), provides a detailed framework for the validation of analytical procedures, including PSA. According to this guideline, the method of PSA should be validated for accuracy, precision, specificity, detection limit, quantitation limit, linearity, and range. 


Reporting of Results 

The results of the PSA must be reported in a clear and accurate manner. This includes the mean particle size, the distribution of the particle sizes, and the percentage of particles within certain size ranges. Any deviations from the expected results must be thoroughly investigated and documented. 


Quality Control 

Regulatory agencies require the implementation of robust quality control measures for PSA. This includes regular calibration of the instrument, the use of reference materials, and the monitoring of results through control charts. 



Complete and accurate documentation is a key regulatory requirement for PSA. This includes the method development and validation, sample preparation, analysis, data interpretation, and any deviations and corrective actions. The documentation should be sufficient to allow for a full understanding and replication of the PSA process. 


Compliance with Pharmacopeia 

The PSA method should comply with the relevant pharmacopeia, such as the United States Pharmacopeia (USP), the European Pharmacopeia (EP), or the Japanese Pharmacopeia (JP). These pharmacopeias provide detailed guidelines on the acceptable methods and standards for PSA.  

Fulfilling these regulatory requirements is not just about compliance; it’s about ensuring the reliability and repeatability of your PSA. This, in turn, guarantees that your drug products consistently meet their intended performance, safety, and efficacy parameters, enhancing patient trust and your organization’s reputation in the market. 


Crafting the Future of Pharmaceuticals with Advanced Particle Size Analysis 


Navigating the complex terrain of drug product development requires an exquisite blend of adopting emerging trends, enforcing best practices, and ensuring regulatory compliance. From harnessing the power of nanotechnology with advanced techniques like Nanoparticle Tracking Analysis (NTA) and Dynamic Light Scattering (DLS), to increasing efficiency with automation, our approach to Particle Size Analysis (PSA) is as innovative as it is rigorous.  

Yet, it’s not just about riding the wave of trends; it’s about a relentless commitment to quality. By meticulously selecting suitable analytical techniques, optimizing parameters, validating methods, and implementing robust quality controls, we ensure our PSA delivers results that are as accurate as they are reliable.  

Furthermore, our adherence to regulatory standards guarantees the repeatability of our PSA, underpinning the consistent performance, safety, and efficacy of our drug products. In essence, our expertise in PSA is not just about crafting high-quality pharmaceuticals; it’s about sculpting the future of drug development, one particle at a time. 




Particle size analysis (PSA) plays an essential role in the pharmaceutical industry, influencing key characteristics of drug products like dissolution rate, bioavailability, stability, and pharmacokinetics. With the industry’s shift towards nanotechnology and complex drug delivery systems, the importance of PSA has become more pronounced.  

Emerging trends such as nanoparticle analysis, automation, and the use of advanced analytical techniques are shaping the landscape of PSA. Nanoparticle Tracking Analysis (NTA) and Dynamic Light Scattering (DLS), for instance, are gaining traction due to their sensitivity in analyzing nanoparticles. Automation is improving efficiency and consistency, while advanced techniques like laser diffraction and imaging methods are providing comprehensive data on particle size, shape, and morphology.  

However, staying abreast of these trends is not enough. It’s equally important to adhere to best practices such as choosing suitable analytical techniques, optimizing analysis parameters, validating methods rigorously, and implementing robust quality control measures. These practices ensure accurate, reliable, and consistent results, enabling organizations to navigate the complexities of drug product development.  

Regulatory compliance is another crucial aspect of PSA. Meeting the requirements set by regulatory bodies and pharmacopeia ensures the reliability and repeatability of the PSA, thereby guaranteeing that drug products consistently meet their intended performance, safety, and efficacy parameters.  

PSA is a critical tool in pharmaceutical development. Keeping pace with trends, adhering to best practices, and meeting regulatory requirements are all integral to maximizing the value of PSA in developing safe, effective, and high-quality drug products. 

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