Particle size analysis is one of the most important processes in pharmaceutical development and manufacturing. The particle size distribution of a formulation directly impacts patient outcomes. By conducting effective particle size analysis, drug developers can improve the quality of their treatments.

How does particle size impact a formulation’s behavior? What are the top reasons pharmaceutical professionals should prioritize particle size analysis in formulation development?

1. Confirm effective immune response

Particle size analysis is crucial for confirming a drug has the correct effect on the patient’s immune system. The particle’s size directly impacts how the body absorbs and processes a drug. If the particles are too large, the respiratory system will simply filter them out. If the particles are too small, they may get exhaled before absorbing properly.

The surface area of a particle determines how fast it dissolves in the body, effectively controlling where a drug is in the bloodstream or digestive system when it is absorbed. Particle size analysis is critical for ensuring a drug gets to the correct part of the body in time to deliver the proper concentration of the active pharmaceutical ingredient.

Without particle size analysis, the drug may dissolve too slowly or too quickly, rendering it ineffective and endangering the patient. In fact, even the shape of the particles can impact formulation efficacy. The shape of the particle changes its surface area and vital properties like diffusion rate.

This is important to note since laser diffraction—the most common method for testing particle size—does not detect particle shape accurately. So, lab professionals need to use additional testing methods to analyze and confirm particle shape if there is concern about irregularity.

2. Determine drug delivery method

The required delivery method and suggestions associated with a drug directly connect to particle size distribution (PSD). For instance, when patients are recommended to take a drug right before or after a meal, it is due to the way the body absorbs the drug. The larger the particle size, the more likely the drug will cause stomach discomfort.

Likewise, inhalation-based drugs rely heavily on ensuring a certain PSD. The respiratory system will only allow particles in a narrow size range through. Outside this range, the particles will simply be filtered or exhaled out. Determining the safest and most effective drug-delivery method requires accurate and detailed particle size analysis testing.

3. Ensure manufacturing quality control

Particle size analysis is essential to pharmaceutical manufacturing as well as formulation. The physical properties of a drug’s particles determine how it needs to be handled during manufacturing.

For instance, compressibility and packing density impact how oral drugs—particularly capsules—must be processed. On average, larger particles have better compression quality but may have worse packing density. Pharmaceutical developers need to find an effective balance to ensure successful manufacturing.

Additionally, particle size analysis is a key part of quality control. Consistent particle size is crucial for many drugs. Even in cases where particle size can safely vary, it also impacts potential manufacturing defects. Pharmaceutical manufacturers need to understand, test and monitor particle size to minimize the likelihood of errors.

4. Predict and minimize side effects

Particle size analysis is one of many tests lab professionals utilize to predict and understand the possible side effects of a formulation. For example, one of the most common side effects is stomach issues such as nausea. Drug developers can reduce the likelihood of this side effect by minimizing particle size as much as possible.

Likewise, particle size contributes to a drug’s safe and effective dosage. For instance, sleep medications and supplements often utilize hormones that are already naturally produced in the body, such as melatonin. They can also trigger increased or decreased levels of other hormones, like serotonin.

Sometimes, these side effects are helpful. This is the case with increases in serotonin and dopamine in some sleeping supplements. However, chain reactions resulting from a drug can easily lead to negative outcomes that affect the patient’s mental and physical health.

Pharmaceutical developers must understand the full range of side effects their formulation could have, both positive and negative. Particle size analysis is a core part of gaining that understanding.

5. Estimate drug shelf life

Particle size analysis is an essential part of estimating the shelf life of a formulation. The particle size determines how the contents of a drug will settle and shift over time, as well as how they may naturally break down or dilute. These factors can eventually alter the drug to the point where it is no longer safe or effective to consume.

Pharmaceutical developers can maximize the shelf life of a formulation by optimizing the particle size for a drug’s other chemical properties. Of course, they can only alter particle size so much before it changes the behavior of the drug. However, it is possible to factor in shelf-life estimations when finalizing the appropriate particle size.

The importance of particle size analysis

Particle size analysis is vital to the pharmaceutical development and manufacturing process. It impacts nearly every aspect of a formulation, from its delivery method to its shelf life.

Lab professionals must prioritize effective particle size analysis to ensure their treatments are safe, effective, and properly sized, dosed and manufactured. In fact, studying particle size can even lead to the development of improved formulations with better performance, fewer adverse effects, and longer shelf life.