Preliminary spectroscopic characterization of PEGylated mucin, a novel polymeric drug delivery system

Abstract

The objective of this study was to evaluate, spectrophotometrically, the compatibility of non-mucinated polyethylene glycol (PEG) 4000 and non-PEGylated mucin in a PEGylated mucin matrices for drug delivery application. Mucin was extracted from the giant African land snails (Archachatina maginata) using chilled acetone and characterized in terms of qualitative properties and solubility profile. Polymeric matrices composed of PEG 4000 and mucin in ratios of 2:0 (A), 1:1 (B), 2:1(C) and 3:1 (D) were prepared by co-precipitation using chilled acetone. The matrices were characterized with respect to compatibility using the Fourier transform infrared (FT-IR) spectroscopy. Results of the qualitative tests performed on the snail mucin showed that carbohydrates, proteins and trace amounts of fats were present; the extracted mucin was light-brownish in colour, with a pleasant meaty odour. Snail mucin, when dispersed in water yielded a slightly viscous dispersion, but is not soluble in ethanol, acetone, 0.1 M sodium hydroxide, ammonium hydroxide and sulphuric acid. The presence of different peaks in the FT-IR spectra of the PEGylated mucin matrices compared with the non-PEGylated mucin (2:0) matrix and non-mucinated PEG 4000 (0:2) matrix indicated the formation of new polymers, which could be employed in drug delivery. This study has shown that PEGylation of mucin gives rise to new polymeric system with principal FT-IR peaks quite different from those of non-PEGylated mucin and nonmucinated PEG, and this may be employed in the delivery of drugs.

Key words: PEGylation, drug delivery, mucin, Fourier transform infrared (FT-IR) spectroscopy, Archachatina maginata.