Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Mar 21;23(4):93.
doi: 10.1208/s12249-022-02234-8.

The Physical Stability of Felodipine and Its Recrystallization from an Amorphous Solid Dispersion Studied by NMR Relaxometry

A Pajzderska  1 , J Mielcarek  2 , J Wąsicki  3   4
Affiliations

The Physical Stability of Felodipine and Its Recrystallization from an Amorphous Solid Dispersion Studied by NMR Relaxometry

A Pajzderska et al. AAPS PharmSciTech. .

Abstract

The 1H nuclear magnetic resonance (NMR) relaxometry method was applied to investigate the physical stability of an active pharmaceutical ingredient (API) and, for the first time, its recrystallization process in an amorphous solid dispersion system (ASD). The ASD of felodipine and polyvinylpyrrolidone (PVP) was prepared using the solvent evaporation method in a mass ratio of 50:50. In the first stage of the study (250 days), the sample was stored at 0% relative humidity (RH). The recovery of magnetization was described by one-exponential function. In the second stage (300 days in 75% relative humidity), the recrystallization process of felodipine was studied, showing in the sample three components of equilibrium magnetization related to (i) crystalline felodipine, (ii) water, and (iii) felodipine and PVP remaining in the ASD. The study shows that the 1H NMR relaxometry method is a very useful tool for analysing the composition of a three-phase system mixed at the molecular level and for the investigation of recrystallization process of API in amorphous solid dispersion system.

Keywords: PVP; amorphous solid dispersion; felodipine; physical stability; recrystallization; relaxometry; time-domain NMR.

PubMed Disclaimer

References

    1. Kawabata Y, Wada K, Nakatani M, Yamada S, Onoue S. Formulation design for poorly water-soluble drugs based on biopharmaceutics classification system: basic approaches and practical applications. Int J Pharm. 2011;42:1–10. - DOI
    1. Renuka, Singh SK, Gulati M, Narang R. Stable amorphous binary systems of glipizide and atorvastatin powders with enhanced dissolution profiles: formulation and characterization. Pharm Dev Technol. 2017;22:13–25. - PubMed - DOI
    1. Takagi T, Ramachandran C, Bermejo M, Yamashita S, Yu LX, Amidon GL. A provisional biopharmaceutical classification of the top 200 oral drug products in the United States, Great Britain, Spain, and Japan Mol Pharm. 2006;3:631-643.
    1. Löbenberg R, Amidon GL. Modern bioavailability, bioequivalence and biopharmaceutics classification system. New scientific approaches to international regulatory standards. Eur J Pharm Biopharm. 2000;50:3–12. - PubMed - DOI
    1. Hancock BC, Parks M. What is the true solubility advantage for amorphous pharmaceuticals? Pharm Res. 2000;17:397–403. - PubMed - DOI

LinkOut - more resources