Utilizing Infrared Spectroscopy to Accurately Determine the Drug Loading Content of Polymeric Nanoparticles

Helenius Ebenebe^*
*Correspondence: Helenius Ebenebe, Department of Chemical Engineering, University of Murcia, 30100 Murcia, Spain, Email:

Introduction

In the realm of pharmaceutical development and drug delivery systems, polymeric nanoparticles have emerged as a promising technology due to their ability to improve the stability, solubility and bioavailability of therapeutic agents. A critical aspect of their development and quality control is the accurate determination of drug loading content-how much drug is incorporated within the nanoparticles. Among various analytical techniques available, infrared spectroscopy has proven to be a highly effective and precise method for this purpose. This article delves into how infrared spectroscopy is utilized to measure drug loading content in polymeric nanoparticles, elucidating the methodology, advantages and potential challenges associated with this technique [1].

Infrared (IR) spectroscopy is a technique used to identify and quantify chemical compounds based on their absorption of infrared light at specific wavelengths. When infrared light passes through a sample, different functional groups within the molecules absorb characteristic wavelengths of light, producing a unique spectrum. This spectrum can be analyzed to determine the presence and concentration of various components in the sample. For accurate measurement, the polymeric nanoparticles must be prepared in a form that is compatible with IR spectroscopy. This typically involves dispersing the nanoparticles in a suitable solvent or incorporating them into a matrix that can be analyzed, such as potassium bromide pellets or Attenuated Total Reflectance (ATR) crystals. Proper dispersion and uniformity are crucial to ensure that the spectra obtained reflect the true composition of the nanoparticles. In transmission spectroscopy method, the sample is mixed with KBr and pressed into a pellet. The IR light passes through the pellet and the resulting spectrum is analyzed to identify the absorption peaks corresponding to the drug and polymer. This method requires careful sample preparation and handling to avoid artifacts [2].

Description

Attenuated Total Reflectance (ATR) IR spectroscopy, is a more recent development that simplifies sample preparation by allowing direct measurement of solid or liquid samples. The sample is placed in contact with an ATR crystal and IR light is reflected within the crystal, interacting with the sample. This technique is less destructive and provides more straightforward sample handling. The IR spectrum of the drug-loaded nanoparticles typically shows characteristic peaks for both the drug and the polymer. Peaks corresponding to the drug and polymer are identified based on their characteristic absorption frequencies. These peaks are compared to spectra of pure drug and pure polymer. The intensity of the drug-specific peaks is analyzed relative to the polymer peaks. Calibration curves are often used to relate peak intensities to drug concentrations. This involves creating a standard curve using known concentrations of the drug and comparing it to the sample spectrum. The drug loading content is calculated by comparing the amount of drug in the nanoparticles to the total amount of nanoparticles, often expressed as a percentage. This can be done by integrating the peak areas or using peak ratios [3].

Infrared spectroscopy is a non-destructive method, preserving the integrity of the sample for further analysis if needed. The technique can detect low concentrations of drugs and differentiate between various functional groups, providing accurate measurements of drug loading content. IR spectroscopy provides quick results with high reproducibility, which is essential for quality control in pharmaceutical manufacturing. Especially with ATR IR spectroscopy, the sample preparation is straightforward, reducing potential errors associated with complex sample handling. The presence of multiple components or overlapping peaks in the IR spectrum can complicate the analysis. Advanced data processing techniques and spectral deconvolution may be required. Accurate quantification requires well-defined calibration curves, which necessitate the preparation of standards with known concentrations. The presence of other excipients or solvents can affect the IR spectrum and must be carefully controlled to avoid inaccuracies [4].

Infrared spectroscopy stands out as a powerful technique for determining the drug loading content of polymeric nanoparticles. Its ability to provide detailed molecular information and quantitative data makes it invaluable in the development and quality control of nanoparticle-based drug delivery systems. By leveraging its advantages while addressing potential challenges, researchers and manufacturers can ensure the optimal performance and efficacy of their therapeutic formulations.

Infrared spectroscopy continues to evolve with advancements in technology and methodology, enhancing its capabilities in drug loading determination for polymeric nanoparticles. Here are some of the advanced applications and techniques that are pushing the boundaries of this analytical method, Two-dimensional infrared spectroscopy is a powerful extension of traditional IR spectroscopy that provides more detailed information about molecular interactions and dynamics. By analyzing cross-peaks in a 2D spectrum, researchers can gain insights into complex molecular environments and the interactions between the drug and the polymer matrix. This technique can improve the accuracy of drug loading measurements by offering a clearer picture of how the drug is incorporated and distributed within the nanoparticles. Infrared microscopy combines IR spectroscopy with optical microscopy to provide spatially resolved IR spectra from specific regions of a sample. This technique is beneficial for analyzing complex nanoparticle formulations where the drug distribution might vary within the sample. Infrared microscopy allows for the investigation of local variations in drug loading, offering a more comprehensive understanding of the nanoparticle system [5].

Conclusion

The future of IR spectroscopy in drug loading determination is likely to see further integration with emerging technologies and methodologies. Developments in computational analysis, machine learning and automated systems could enhance the efficiency and accuracy of IR spectroscopy. Additionally, innovations in IR instrumentation and sample handling are expected to broaden the applicability of the technique to a wider range of nanoparticle systems and drug formulations. Infrared spectroscopy remains a cornerstone technique for determining drug loading content in polymeric nanoparticles. Its ability to provide detailed molecular information, combined with advancements and complementary analytical techniques, continues to advance its role in pharmaceutical research and quality control. By leveraging these capabilities and addressing practical challenges, researchers and manufacturers can achieve more accurate and reliable drug delivery systems, ultimately improving therapeutic outcomes.

Acknowledgement

None.

Conflict of Interest

There are no conflicts of interest by author.

References

1. Bobo, Daniel, Kye J. Robinson, Jiaul Islam and Kristofer J. Thurecht, et al. "Nanoparticle-based medicines: A review of FDA-approved materials and clinical trials to date." Pharm Res 33 (2016): 2373-2387.

   Google Scholar, Crossref, Indexed at

2. Kalepu, Sandeep and Vijaykumar Nekkanti. "Insoluble drug delivery strategies: Review of recent advances and business prospects."Acta Pharm Sin B5 (2015): 442-453.

   Google Scholar, Crossref, Indexed at

3. Karimi, Mahdi, Amir Ghasemi, Parham Sahandi Zangabad and Reza Rahighi, et al. "Smart micro/nanoparticles in stimulus-responsive drug/gene delivery systems."Chem Soc Rev 45 (2016): 1457-1501.

   Google Scholar, Crossref, Indexed at

4. Fang, Jun, Rayhanul Islam, Waliul Islam and Hongzhuan Yin, et al. "Augmentation of EPR effect and efficacy of anticancer nanomedicine by carbon monoxide generating agents."Pharm 11 (2019): 343.

   Google Scholar, Crossref, Indexed at

5. Elzoghby, Ahmed O., Wael M. Samy and Nazik A. Elgindy. "Albumin-based nanoparticles as potential controlled release drug delivery systems."J Control Release 157 (2012): 168-182.

   Google Scholar, Crossref, Indexed at