Design of an Antibiotic-Releasing Polymer: Physicochemical Characterization and Drug Release Patterns

Abstract

Conventional drug delivery has its share of shortcomings, especially its rapid drug release with a relatively short duration of therapeutic drug concentrations, even in topical applications. Prolonged drug release can be effectively achieved by modifying the carrier in a drug delivery system. Among the several candidates for carriers studied over the years, poly (ether ether ketone), a biocompatible thermoplastic, was chosen as a suitable carrier. Its inherent hydrophobicity was overcome by controlled sulfonation, which introduced polar sulfonate groups onto the polymer backbone. Optimization of the sulfonation process was completed by the variation of the duration, temperature of the sulfonation, and concentration of sulfuric acid. The sulfonation was confirmed by EDS and the degree of sulfonation was determined by an NMR analysis (61.6% and 98.9%). Various physical properties such as morphology, mechanical strength, and thermal stability were studied using scanning electron microscopy, tensile testing, and thermogravimetric analysis. Cytotoxicity tests were performed on the SPEEK samples to study the variation in biocompatibility against a Vero cell line. The drug release kinetics of ciprofloxacin (CP) and nalidixic acid sodium salt (NA)-loaded membranes were studied in deionized water as well as SBF and compared against the absorbance of standardized solutions of the drug. The data were then used to determine the diffusion, distribution, and permeability coefficients. Various mathematical models were used to fit the obtained data to establish the order and mechanism of drug release. Studies revealed that drug release occurs by diffusion and follows zero-order kinetics.

Sulfonated Polyether Ketone Membranes Embedded with Nalidixic Acid—An Emerging Controlled Drug Releaser

“…The sulfonated polymers, with a high degree of sulfonation, can swell or form emulsion and were found to be difficult to isolate [42]. In the reported literature, the SPEEK polymer showed degradation and elevated hydrophilicity as the sulfonation increased which is similar to the current investigation [43,44]. The polymer PEK's insolubility and high melting temperatures impose processing and polymerization constraints [40]; due to this behavior, the PEK has a lower rate of sulfonation than the PEEK.…”

Intrinsically Disordered Synthetic Polymers in Biomedical Applications

“…The drug release rate can be determined by measuring the amount of drug released over time [ 108 ]. This can be effected by using various analytical techniques, such as UV-Vis spectroscopy, high-performance liquid chromatography (HPLC), or mass spectrometry.…”

Synthesis and Characterization of Ciprofloxacin Loaded Star-Shaped Polycaprolactone–Polyethylene Glycol Hydrogels for Oral Delivery

“…This type of mechanism typically indicates a release behavior that deviates significantly from Fickian diffusion, where the drug-release rate is not solely dependent on the concentration gradient but may involve additional factors like erosion, swelling, or relaxation of the matrix material. Regardless of the solubility of the antibiotic, the release of drugs from the hydrogel was most likely regulated via a diffusion mechanism [48,49]. Fick diffusion suggested that the hydrogel network was relaxed after the dissolution medium penetrated the hydrogel matrix.…”