The Benefits of Pharmaceutical Particle Size Testing
Jan 27, 2016
Researchers avail many documents that link particle size with drug performance in terms of the rates of absorption, dissolution, and content uniformity. One of the benefits of pharmaceutical particle size testing is to help pharmaceutical companies in their effort to manufacture and formulate many of their dosage forms appropriately. There are various approaches and technique such as Laser Diffraction Measurement available to perform the testing depending on the product formulation. An intensive study of the particle size, from drug development stage to manufacturing, can enable them to develop safe, efficient and stable products. This is because they can control contaminating particles and improve drug performance as discussed below.
Reducing contamination
Testing the size of drug particles will serve as an indicator of contamination. Following this, a company can install measures to control the limits of the contaminating particles, which is critical especially for parenteral or injectable solutions. Here are some of the potential results of excessive contamination in drug solutions.
Drugs with particle contamination can have a direct adverse reaction in a user’s body. For instance, particles of a certain size can physically block blood flow such as in the lungs, or the particle may be distributed in the body via the blood and can lead to toxicity to certain organs or tissues.
Particle contamination can also contribute to adverse reaction indirectly. A drug user’s immune system can identify certain particles as foreign material, making it impose secondary effects.
Therefore, it is vital for pharmaceutical companies to use various techniques available for characterization of limits in order to guarantee high-quality product and to protect their patients.
Improving drug performance
The particle size of the material a company uses to make its pharmaceutical excipients and drug substances have an impact on both the physical and chemical behavior of the final product. As a result, the size is significant for the behavior of granulates, emulsions, powders, creams, and liquids, among others concerning:
Solubility
Bioavailability
Filterability
Flowability
Adhesive strength
Thermal conductivity
Drying properties
Particle size testing is particularly essential when a company is using new drug delivery formats such as nanoparticles and liposomes. It is particularly a requirement during stability testing before a company releases the drug to the market. This particle testing is an important activity for every pharmaceutical company to consider in achieving a consistent product.
Bioavailability of suspension or solid delivery systems is related to particle size in that the particle size controls the solubility or dissolution characteristics. Drug dissolution is faster for finer particle size and vice versa. The distribution of this particle size is also a significant factor as a narrow distribution result to more uniform dissolution. It may take some time for formulations with a relatively large particle to dissolve completely.
Stability is a critical issue when it comes to suspensions since there is a greater likelihood of non-uniform delivery if the active ingredients settle. Studies have strongly related the settling velocity of these particles in suspension to the size of the particle as well as the physical characteristic of the fluid. Thus, particle size testing can help a company to achieve an appropriate settling velocity, which it can easily attain with finer particles.
Furthermore, particle size may influence the behavior of a formulation during processing, which will ultimately affect its content uniformity. For instance, during the direct compression tableting process, the size of the particle can influence the rate at which powder flows via the press, compressibility and the segregation behavior of the formulation. Intensive Study of particle size can thus help a company to improve the consistency of its tablet’s composition and weight, and the mechanical properties of the final product. It can also improve how the press works.
In conclusion, researchers are using sophisticated analytical techniques to show that particle size, as well as shape, can be influential. Since health policies regarding safety assessment of drugs require all information about potential contaminants of infusions and injections, pharmaceutical companies need to conduct particle size testing. Many companies within the industry of dry powder inhalers, tablets, creams and suspensions are recently assigning particle size specifications for their pharmaceutical products.