Hollow, pH‐sensitive calcium–alginate/poly(acrylic acid) hydrogel beads as drug carriers for vancomycin release

GÜNEŞ²,

2022

Ankara Ecz. Fak. Derg.

Objective: Objective: Designing matrix structured controlled release systems using polymers or waxy lipids is a popular option today. Hollowbeads are formulations characterized by the formation of an air-filled cavity inside. In our study, indomethacin was chosen as a model drug. Cetyl alcohol was selected to create the hollowbeads structure, and NaCMC was chosen to achieve long-term release. Kollicoat® MAE100P was used to reduce and/or prevent ulcer formation and control release.Material and Method: The formulations were prepared using a new “wax removal” technique. Different concentrations of ZnCl2 and CaCl2 were used as crosslinkers. In the preformulation studies, 24 different formulations were prepared by changing the amount of NaCMC, the amount of crosslinker, and the crosslinking time. The structure, size, encapsulation efficiency, yield, hollow structure, and long-term release capacity were investigated in the formulations. These parameters were statistically evaluated depending on the amount of NaCMC, the type of crosslinker, the amount of crosslinker, and contact times with the crosslinker.Result and Discussion: Hollowbeads were characterized by SEM and FT-IR. In vitro release studies, release kinetics, and release mechanisms were performed in pH 1.2 HCl and pH 6.8 phosphate buffer media. Swelling, and buoyancy studies were performed. The long-term stability, encapsulation efficiencies, drug loading efficiencies, and yields of the formulations were also evaluated. Two promising formulations (F2 and F19) were found to be able to release indomethacin in both the stomach and intestinal media for 24 hours.

Section: Ft-ir Analysis Of Hollowbeadssupporting

confidence: 83%

Section: In Vitro Release Study Of Hollowbeadsmentioning

confidence: 99%

İndometazi̇n İçeren Yüzen-Pulsati̇l İçi̇ Boş Boncuklarin Hazirlanmasi Ve i̇n-Vi̇tro Karakteri̇zasyonu

GÜNEŞ²,

2022

Ankara Ecz. Fak. Derg.

Saudi Pharmaceutical Journal

“…A large group of systems, used as drug carriers are hydrogels (Peppas et al, 2000, Hamidi et al, 2008). Vancomycin can be encapsulated within hydrogel beads (Lin et al, 2010) or it can be covalently bonded in order to form antibacterial hydrogel (Lakes et al, 2014). Hydrogels with vancomycin can be applied as wound healing dressings (Zhang et al, 2008, Zhao et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

Halloysite nanotubes as carriers of vancomycin in alginate-based wound dressing

Kurczewska

Pecyna

Ratajczak

et al. 2017

The influence of an inorganic support - halloysite nanotubes - on the release rate and biological activity of the antibiotic encapsulated in alginate-based dressings was studied. The halloysite samples were loaded with approx. 10 wt.% of the antibiotic and then encapsulated in Alginate and Gelatin/Alginate gels. The material functionalized with aliphatic amine significantly extended the release of vancomycin from alginate-based gels as compared to that achieved when silica was used. After 24 h, the released amounts of the antibiotic immobilized at silica reached 70%, while for the drug immobilized at halloysite the released amount of vancomycin reached 44% for Alginate discs. The addition of gelatin resulted in even more prolonged sustained release of the drug. The antibiotic was released from the system with a double barrier with Higuchi kinetic model and Fickian diffusion mechanism. Only the immobilized drug encapsulated in Alginate gel demonstrated very good antimicrobial activity against various bacteria. The inhibition zones were greater than those of the standard discs for the staphylococci and enterococci bacteria tested. The addition of gelatin adversely affected the biological activity of the system. The inhibition zones were smaller than those of the reference samples. A reduction in the drug dose by half had no significant effect on changing the release rate and microbiological activity. The toxicity studies of the material with immobilized drug were carried out with and . The material studied had no effect on the living organisms used in the bioassays. The proposed system with a double barrier demonstrated high storage stability.

Adv Materials Technologies

“…The different sensitivity observed between E. coli and S. aureus in the presence of the antibiotic can be associated with the higher toxicity of vancomycin exerted against gram-positive bacterial strains. [60,61] Vancomycin inhibits the biosynthesis of the D-Ala-D-Ala dipeptide composing the peptidoglycan that is the main constituent of the gram-positive cell wall. [62] Since the outer membrane of gram-negative strains acts as a barrier to avoid the entrance of vancomycin, high concentrations of this antibiotic are needed to observe an inhibitory effect.…”

Section: Antibacterial Efficacy Of Drug-loaded Cryostructured Scaffoldsmentioning

confidence: 99%

Combining 3D Printing and Cryostructuring to Tackle Infection and Spine Fusion

Fischetti,

Graziani,

Ghezzi

et al. 2024

Low back pain is among the main issues in vertebral orthopaedics. Intervertebral disk degeneration can be severe, up to requiring the replacement of the damaged disk by substitutes to achieve spine fusion. Disk removal results in critical size defects, so fusion does not occur naturally, but synthetic bone grafts are needed. Since the surgical procedure is time‐consuming, high infection rates occur. Hence, in spine fusion, bone regeneration enhancement and infection prevention are needed. Here, a new dual‐component system is proposed, to tackle both issues at one time. To enable spine fusion, 3D extrusion‐based printing is employed to develop coherent custom magnesium phosphate (CaMgP)‐based cages. The 3D‐printed scaffolds are hardened, and the structural properties are evaluated to be within the ranges of physiological bone. To prevent infection, an in‐house ice‐templating device is employed in combination with a 3D‐printed ceramic scaffold, to develop tailored porous alginate structures loaded with vancomycin. Results show that CaMgP can be printed into complex geometries and that the geometry influences the pore orientation during ice‐templating. These structures loaded with vancomycin have antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) strains.