Papers by Keyword: Vancomycin

Abstract: UV-Vis spectrophotometric method was validated for the stability assessment of 5% extemporaneous vancomycin eye drops in different vehicles. The eye drops were extemporaneously prepared by dissolving vancomycin in various vehicles, including sterile water for injection (SWI), 0.45% normal saline (0.45%NSS) and artificial tear. The solutions were stored at room temperature and in refrigerator for 30 days. The content of vancomycin was measured by UV-Vis spectrophotometer at 280 nm. UV-Vis Spectrophotometric method was validated according to ICH guideline. The results indicated that the method was precise and accurate. The calibration curve was linear with r² = 0.9997 in the range of 40-160 μg/mL. LOD and LOQ were 3.39 and 10.26 μg/mL, respectively. The results showed that the percentage of vancomycin residual concentation in SWI and 0.45%NSS was decreased to less than 90% after storage at room temperature for 8 days, whereas the residual concentration of vancomycin in artificial tear was less than 90 % after 10 days in room temperature. Meanwhile the percentage of vancomycin residual concentation in all formulations was remarkably decreased to less than 90% after storage in refrigerator for 17 days. The physical appearance of eye drops in artificial tear remained unchanged. However the observed color of other formulations was gradually changed to yellow in day 7 at room temperature and day 17 in refrigerator. The pH values of all preparations were within the general U.S. pharmacopeia national formulation range of 2.5-4.5. In conclusion, the eye preparations of 5%w/v vancomycin in all selected vehicle were stable for 17 days in refrigerator (2-8°C).

Abstract: Conventional calcium phosphate bone cements are self setting water based pastes. Recently pre-mixed calcium phosphate bone cements have been proposed that have non-aqueous fluid as liquid phase of the paste. Such cements thus only start setting reaction in contact with body fluids. In this work the properties (cohesion, compressive strength, phase composition) of pre-mixed calcium phosphate cements based on α-tricalcium phosphate and calcium dihydrogen phosphate monohydrate are described. Properties of several cement compositions are examined and compared to properties of β-tricalcium phosphate and calcium dihydrogen phosphate monohydrate based cements. It was found that α-tricalcium phosphate and calcium dihydrogen phosphate monohydrate based cements have higher compressive strength (10 - 15 MPa) than corresponding β-tricalcium phosphate and calcium dihydrogen phosphate monohydrate based cements (10 - 6 MPa). Out of examined cement paste liquids (glycerol, polyethylene glycol and polypropylene glycol) cements using glycerol as the liquid phase had higher compressive strength and are more cohesive.

Abstract: In the present study, a new antibacterial bone graft substitute has been developed for repairing bone defects and inhibiting related infections at the same time. Calcium sulphate hemihydrate (CSH) was introduced into nanohydroxyapatite/collagen (nHAC) to prepare a self-setting in situ bone repair materials. The nHAC/CSH was used as a carrier of vancomycin (VCM) for anti-infection and the treatment of osteomyelitis. The VCM/nHAC/CSH composite was a porous scaffold with porosity of 38.8% and the compressive mechanical strength was about 4.8 MPa. The final setting time was about 15~20 min. The inhibition ratio of VCM/nHAC/CSH was more than 99.8% and the distinct inhibition zone of 18 mm was formed in Staphylococcus aureus bacterium incubation dish with VCM/nHAC/CSH disc in the center of agar matrix for 16 hours of incubation. After incubating 17 days at 37 in vitro, the concentration of vancomycin in elution fluild was around 12 μg/mL. Therefore, the VCM/nHAC/CSH bone substitute presents ideal self-setting antibacterial, cytocompatibility, sustained release properties and has great potential applications for the treatment of bone defect-related infection in orthopedic surgeries.

Abstract: A novel microsphere scaffolds composed of chitosan and β-TCP containing vancomycin was designed and prepared. The β-TCP/chitosan composite microspheres were prepared by solid-in-water-in-oil (s/w/o) emulsion cross-linking method with or without pre-cross-linking process. The mode of vancomycin maintaining in the β-TCP/chitosan composite microspheres was detected by Fourier transform infrared spectroscopy (FTIR). The in vitro release curve of vancomycin in simulated body fluid (SBF) was estimated. The results revealed that the pre-cross-linking prepared microspheres possessed higher loading efficiency (LE) and encapsulation efficiency (EE) especially decreasing the previous burst mass of vancomycin in incipient release. These composite microspheres got excellent sphere and well surface roughness in morphology. Vancomycin was encapsulated in composite microspheres through absorption and cross-linking. While in-vitro release curves illustrated that vancomycin release depond on diffusing firstly and then on the degradation ratio later. The microspheres loading with vancomycin would be to restore bone defect, meanwhile to inhibit bacterium proliferation. These bioactive, degradable composite microspheres have potential applications in 3D tissue engineering of bone and other tissues in vitro and in vivo.

Abstract: This work compares the ophthalmic delivery of vancomycin 50 mg/ml eye drops using 5 different vehicles, namely: 0.3% w/v chitosan, 0.3% and 0.4% w/v HPMC (Methocel E4M), Tears Naturale^TM II and 0.9% w/v sodium chloride solution. In vitro and in vivo studies were carried out and the results evaluated in terms of viscosity, compatibility, stability, clarity, minimum inhibitory concentration (MIC) and pharmacokinetics. The viscosity of Tears Naturale^TM II was comparable with that of HPMC (0.3% pH 7.1) but was higher than 0.3% w/v chitosan. The percent labeled amounts and MIC of vancomycin 50 mg/ml in all of the vehicles were stable for 30 days at 2-8°C, while the clarity in 0.3% w/v chitosan, 0.3% and 0.4% HPMC (pH 7.1), Tears Naturale^TM II and 0.9% sodium chloride solution was stable for 30, 14, 1 and 3 days respectively at 2-8°C. In vivo pharmacokinetic determinations of the AUC of tear film reciprocal of minimum inhibitory titer showed that vancomycin 50 mg/ml in 0.3% w/v chitosan, 0.3% and 0.4% w/v HPMC pH 7.1 and Tears Naturale^TM II were significantly different from 0.9% sodium chloride solution. At the present time, chitosan is undergoing clinical trials in Thailand with a view to its use in ophthalmology, while HPMC (0.3% w/v) in pH 7.1 has already been approved for use as a vehicle in ophthalmology for the delivery of vancomycin 50 mg/ml in extemporaneous eye drops.

Abstract: A different range of vancomycin was incorporated into a poly dl-lactide-co-glycolide) [PLGA] disc matrix using the hot compression method. The disc was placed in phosphate buffered saline (PBS) and incubated at 37oC. The PBS was changed periodically, and the removed solution was analyzed using high performance liquid chromatography. The sensitivity of the antibiotic-polymer matrix was evaluated using cultured-human-ear methicillin-resistant staphylococcus aureus (MRSA). The MRSA growth was inhibited proportionally to the incorporated vancomycin concentration in the disc matrix. A disc incorporating 400 µg of antibiotics inhibited the growth of MRSA 10 times longer than the disc containing 30 µg as a control. It was found that the biodegradable polymer matrix enabled the control-release of an antibiotic, and the release profile was observed as zero order.