Synthesis and evaluation of chitosan-graft-poly (2-hydroxyethyl methacrylate-co-itaconic acid) as a drug carrier for controlled release of tramadol hydrochloride

Abstract

Chitosan-graft-poly (2-hydroxyethyl methacrylate-co-itaconic acid) has been synthesized for different feed ratios of 2-hydroxyethyl methacrylate and itaconic acid and characterized by FT-IR, thermogravimetry and swelling in simulated biological fluids (SBF) and evaluated as a drug carrier with model drug, tramadol hydrochloride (TRM). Grafting decreased the thermal stability of chitosan. FT-IR spectra of tablet did not reveal any molecular level (i.e. at <10 nm scale) drug-polymer interaction. But differential scanning calorimetric studies indicated a probable drug-polymer interaction at a scale >100 nm level. The observed Korsmeyer-Peppas's power law exponents (0.19-1.21) for the in vitro release profiles of TRM in SBF and other drugs such as 5-fluorouracil (FU), paracetamol (PCM) and vanlafaxine hydrochloride (VNF) with the copolymer carriers revealed an anomalous drug release mechanism. The decreased release rates for the grafted chitosan and the enhanced release rate for the grafts with increasing itaconic acid content in the feed were more likely attributed to the enhanced drug-matrix interaction and polymer-SBF interactions, respectively. The different release profiles of FU, PCM, TRM and VNF with the copolymer matrix are attributed to the different chemical structures of drugs. The above features suggest the graft copolymer's candidature for use as a promising oral drug delivery system.

Preparation of novel tissue acidosis-responsive chitosan drug nanoparticles: Characterization and in vitro release properties of Ca2+ channel blocker nimodipine drug molecules

“…Moreover, the peak at 1576 cm -1 (pure Chit, amide II. peak (Tipson, 1968;Subramanian & Vijayakumar, 2012)) shifts to 1562 cm -1 (N-H deformation in secondary amines (Tipson, 1968) in the case of hydrophobically modified samples and its absorbance increases, which further proves that the reaction was successful. The further bands present in all samples are: 3363 and 3295 cm -1 (N-H stretching for primary and secondary amines (Hoffmann et al, 2009)), overlapped with a broad band for O-H stretching.…”

“…The band at 2875 cm -1 can be attributed to C-H stretching (probably CH 3 (Rahmi et al, 2015)) and the band at 1380 cm -1 is for C-H deformation in CH 3 group (Rahmi et al, 2015). Amide peaks (Subramanian & Vijayakumar, 2012): I. at 1650, II. at 1576, III.…”

“…The absence of bands in the 2830-2695 cm -1 region (C-H stretching in the H-C=O group of aldehydes (Tipson, 1968)) and in the 1740-1720 cm -1 region (C=O stretching (Tipson, 1968) shows that no residual aldehydes were remained in the samples after the washing process. In the case of pure Chit the band at 1650 cm -1 (amide I peak (Subramanian & Vijayakumar, 2012)) was shifted to 1623 and 1626 cm -1 , respectively and the absorbance decreased, which shows that the amide groups of pure Chit disappeared due to the effect of sodium cyanoborohydryde, and primary amine groups formed which explains that the absorbance maximum is near 1620 cm -1 (N-H deformation for primary amine group in D-glucosamine (Tipson, 1968)). This band can also be attributed to the -C=N-stretching (1624-1635 cm -1 (Hoffmann et al, 2009)) which shows that the chitosan primary amine groups and the aldehydes successfully reacted and formed an imine, as shown in Figure 1.…”

Synthesis of a branched photosensitive copolymer and its application for negative‐type photoresists

“…The first stage of weight loss, occurring from 180 to 250°C, was attributed to the degradation of the terminal groups grafted by HEMA . The second stage, appearing from 250 to 300°C, was ascribed to polymer chain degradation, a complex process including double‐bond thermal crosslinks, and the weight loss in this stage reached a maximum …”

Permeability of Novel Chitosan-<em>g</em>-poly (Methyl Methacrylate) Amphiphilic Nanoparticles in a Model of Small Intestine <em>in Vitro</em>

“…The synthesis of the CS-g-PMMA copolymer was carried out by the thermal free radical polymerization of MMA in the presence of CAN in nitric acid [26,35]. Both reactive -OH and -NH2 groups may form a complex with Ce(IV) cation, which will dissociate and create free radical sites on the CS backbone for future attack of the double bond of MMA and polymerization to render the amphiphilic derivative (Figure 1).…”