Influence of isostatic compression on the stability of vancomycin loaded with a calcium phosphate-implantable drug delivery device

Abstract

It is essential to prevent microbial infections after osteoarticular trauma or prosthesis implantation. As an alternative to antibiotic parenteral administration, antibiotic-loaded biomaterials allow high concentrations to be obtained in situ without systemic toxicity. Although the formulation of biphasic calcium-phosphate (BCP)-vancomycin granules by isostatic compression has recently been used to produce drug-delivery devices, the stability of vancomycin needs to be proven. In this study, vancomycin was associated with BCP powders by isostatic compression at 100, 140, or 200 MPa and then extracted or released by a rotating paddle system for 24 h. Vancomycin assays were performed by spectrophotometric and microbiological methods. The results show that all vancomycin associated with the material was recovered after extraction without degradation. Thus, vancomycin was not denaturated after application of 100, 140, or 200 MPa of isostatic compression. The results for vancomycin released from granules compressed at the three pressures were not significantly different (p =.01) whether assays were performed microbiologically or spectrophotometrically, indicating a good correlation between the two methods. This process involving high pressure appears to be a good means of developing drug delivery devices loaded with therapeutic agents without denaturating the components.

Biaxial flexure testing of calcium phosphate bioceramics for use in tissue engineering

“…For BCP, minor phases of HA and β‐TCP, and α‐TCP were present. As has been used in a number of recent studies, the HA/β‐TCP peak ratios were estimated using the simple peak height law,35–38 where the HA/β‐TCP ratio was found to be approximately 61% HA using where I 100,HA and I 100β‐TCP are the intensities of the maximum intensity peaks of HA and β‐TCP, respectively 35. XRD analysis of the Group IV OB‐seeded samples (after mechanical testing) showed that the BCP discs in Group IV were only 53%, with an error of ± 7 to 10% HA 35.…”

Optimization of the process of gelatin-ceftiofur sodium microspheres

“…On the basis of the experimental conditions of orthogonal test scheme to prepare microspheres, the concrete steps are as follows: particle size of 500 microspheres in each group was measured , and then to calculate the average particle size d (particle size was measured by the optical microscope); 500 microspheres in each group were extracted to count the number of adhesion microspheres N, according to the formulas (3)-(5) to calculate S1, S2, S3, and then according to the formula (6) to calculate the total S, the results are shown in Table 3.…”

Effect of metal-ion-to-fuel ratio on the phase formation of bioceramic phosphates synthesized by self-propagating combustion

“…The pH of the solution was then adjusted to 9.5 by adding NH 4 OH and water in a 1 : 1 ratio. A stoichiometric amount of 1 M (NH 4 ) 2 HPO 4 solution was added to the above mixture and the precipitated mixture of phosphates was dissolved by adding concentrated HNO 3 until the pH became 1.…”

“…Because of its biocompatibility and osteoconductive [1] properties, it has many biological applications including as a bone graft substitute [2,3], a sustained-release drug delivery device [4] and for protein purification. However, biological apatite differs from pure and synthetically produced calcium hydroxyapatite (HAP) in terms of stoichiometry, composition, crystallinity and other physical and mechanical properties.…”