Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Soluble curcumin prepared by solid dispersion using four different carriers: Phase solubility, molecular modelling and physicochemical characterization

Mohamed J Muthu, K Kavitha , Karthikeyini S Chitra, S Nandhineeswari

Department of Pharmaceutical Technology, BIT Campus, Anna University, Tiruchirappalli 620024, Tamil Nadu, India;

For correspondence:- K Kavitha Email: kavithaaut@gmail.com Tel:+919841954918

Accepted: 29 July 2019 Published: 27 August 2019

Citation: Muthu MJ, Kavitha K, Chitra KS, Nandhineeswari S. Soluble curcumin prepared by solid dispersion using four different carriers: Phase solubility, molecular modelling and physicochemical characterization. Trop J Pharm Res 2019; 18(8):1581-1588 doi: 10.4314/tjpr.v18i8.2

© 2019 The authors.
This is an Open Access article that uses a funding model which does not charge readers or their institutions for access and distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0) and the Budapest Open Access Initiative (http://www.budapestopenaccessinitiative.org/read), which permit unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited..

Abstract

Purpose: To prepare curcumin solid dispersions (SDs) using four different carriers, evaluate their thermodynamic properties, and carry out physicochemical characterization on them.

Methods: Solid dispersions (SDs) of curcumin were prepared using hot melt method. Hydrophilic carriers, including poloxamers (P-407 and P-188), gelucire 50/13 and mannitol were used in the ratios of 1:3, 1:4, 1:5, 1:6 and 1:7 (curcumin : carrier). The new formulations were characterized in the liquid state by phase solubility studies (PSS), and in the solid state using Fourier transform infrared (FTIR) spectroscopy, powder x-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). Molecular modelling (MM) was also performed on the SDs.

Results: The results of PSS revealed an AL-type phase-solubility pro@257;le with spontaneous binding process, indicating 1:1 stoichiometry. The stability constant (Ka) of curcumin with various carriers at 25 and 37 °C were in the order: P-407 (631.9 and 524.9 M^-1) > P-188 (436.48 and 388.28 M^-1) > gelucire (100.14 and 112.05 M^-1) > mannitol (10.88 and 11.90 M^-1). The maximum stability constants of P-407 at 25 and 37 °C were 631 and 524 M^-1, respectively, which produced an accurate fit on MM (in silico model). Curcumin-P-407 complex produced enhanced solubility property (318 ± 14.46-fold). Physicochemical characterization revealed a shift in curcumin structure from crystalline to amorphous form without any chemical alterations, thereby enhancing solubility.

Conclusion: These results shown that the solubility of curcumin is greatly improved after its complexation with P-407 in SD, and the drug is converted into amorphous form without significant chemical modification.

Keywords: Curcumin, Carrier, Phase solubility, Molecular modelling, Physicochemical characterization