Dual Cross-Linked Carboxymethyl Sago Pulp-Gelatine Complex Coacervates for Sustained Drug Delivery

Abstract

Abstract:In the present work, we report for the first time the complex coacervation of carboxymethyl sago pulp (CMSP) with gelatine for sustained drug delivery. Toluene saturated with glutaraldehyde and aqueous aluminum chloride was employed as cross-linkers. Measurements of zeta potential confirm neutralization of two oppositely charged colloids due to complexation, which was further supported by infrared spectroscopy. The coacervates encapsulated a model drug ibuprofen and formed microcapsules with a loading of 29%-56% w/w and an entrapment efficiency of 85%-93% w/w. Fresh coacervates loaded with drug had an average diameter of 10.8 ± 1.93 µm (n = 3 ± s.d.). The coacervates could encapsulate only the micronized form of ibuprofen in the absence of surfactant. Analysis through an optical microscope evidenced the encapsulation of the drug in wet spherical coacervates. Scanning electron microscopy revealed the non-spherical geometry and surface roughness of dried drug-loaded microcapsules. X-ray diffraction, differential scanning calorimetry and thermal analysis confirmed intact and crystalline ibuprofen in the coacervates. Gas chromatography indicated the absence of residual glutaraldehyde in the microcapsules. Dual cross-linked OPEN ACCESSPolymers 2015, 7 1089 microcapsules exhibited a slower release than mono-cross-linked microcapsules and could sustain the drug release over the period of 6 h following Fickian diffusion.

Influence of Ispaghula and Zein Coating on Ibuprofen-Loaded Alginate Beads Prepared by Vibration Technology: Physicochemical Characterization and Release Studies

“…The peaks in 1508, 1456 and 780 cm −1 are associated with the vibration in the skeleton of benzene. These peaks were in accordance with our previous publication [ 13 ]. All these ibuprofen peaks were intact and present in similar intensities in alginate and alginate–ispaghula beads ( Figure 2 B–E), thus confirming the absence of drug–polymer interaction.…”

“…DSC thermogram of ibuprofen ( Figure 5 ) has shown a sharp crystalline endothermic peak at 79 °C [ 13 , 15 ] due to melting. The drug-loaded alginate and alginate–ispaghula beads were shown with peaks at 77.5 and 76 °C, respectively, indicating the crystalline and stable nature of ibuprofen.…”

“…The filtrates were made up to 100 mL with phosphate buffer (pH 6.8) and estimated with UV–vis spectrophotometer (UV-1800, Shimadzu, Kyoto, Japan) at 264 nm. The theoretical percentage of drug loading (TDL) was calculated using the following equations [ 13 ]. TDL = (Weight of drug added (g)/Weight of polymers and drug added (g)) × 100 …”

“…Ibuprofen, a nonsteroidal anti-inflammatory drug [ 2 ] is used as a model drug in the encapsulation process. The pKa of ibuprofen is reported between 4.9 and 5.2 [ 13 ]. It is less ionised in the pH less than 2 and more ionised at pH 6.9 and above.…”

Recent Advances in Complex Coacervation Design from Macromolecular Assemblies and Emerging Applications

“…Despite coacervation has been studied since almost one century ago, it still attracts great interest because of their wide applications in water treatment, [ 12,13 ] material purification, [ 14,15 ] and pharmaceutical microencapsulations. [ 16–18 ]…”