Cephalexin‐loaded injectable macroporous calcium phosphate bone cement

Abstract

Different types of calcium phosphate cements (CPCs) have been studied as potential matrices for incorporating different types of antibiotics. All of these matrices were morphologically microporous whereas macroporosity is essential for rapid cement resorption and bone replacement. In this study, liberation of cephalexin monohydrate (CMH) from a macroporous CPC was investigated over 0.5-300 h in simulated body fluid and some mathematical models were fitted to the release profiles. Macroporosity was introduced into the cement matrix by using sodium dodecyl sulfate molecules as air-entraining agents and the effect of both surfactant and CMH on basic properties of the CPC was studied. Incorporation of CMH into the CPC composition increased the setting time, decreased the crystallinity of the formed apatite phase, and improved the injectability of the paste. The use of both CMH and sodium dodecyl sulfate did not affect the rate of conversion of the reactants into apatite phase while soaking the cements in simulated body fluid. Results showed that the liberation rate of the drug from porous CPC was higher than that of the nonporous CPC but same release patterns were experienced in both types of cements, that is, like to nonporous CPC, a time-dependent controlled release of the incorporated drug was obtained from macroporous CPC. The Weibull model was the best fitting-equation for release profiles of all cements. The liberated CMH was as active as fresh cephalexin. It is concluded that this macroporous CPC can be successfully used as drug carrier with controlled release profile for the treatment of bone infections.

Changes in the drug release pattern of fresh and set simvastatin-loaded brushite cement

“…Structural properties such as microstructure, porosity and tortuosity play a critical role on the drug diffusion from the bulk material and are therefore linked to the release profiles recorded [21]. In this work, the structural properties at different reaction points as well as the drug release patterns of the cement were monitored.…”

“…Moreover, in several studies [18][19][20][21][22] the conditions used were not indicated. Hence, most studies in the literature disregard the fact that the release pattern may change depending on the time the cement was set for; only Canal et al compared the drug release patterns of cements set for different times (1 h vs 7 days), but this was done on apatitic cements only [10].…”

Self-Setting Calcium Orthophosphate Formulations: Cements, Concretes, Pastes and Putties

“…Additional advantages are provided if the material is injectable, biodegradable, sets at ambient temperature, has both near neutral pHs and a large surface area [36,37]. These properties make self-setting calcium orthophosphate formulations to be very attractive candidates as drug carriers for therapeutic peptides [537], antibiotics [538][539][540][541][542][543][544][545][546][547], anticancer drugs [578], anti-inflammatory drugs [549,550], cytokines [551], hormones [552] and bone morphogenetic proteins [432,[553][554][555][556][557]. For example, a "growth factor cement" has been reported [558].…”

Self-Setting Calcium Orthophosphate Formulations

“…Additional advantages are provided if the biomaterial is injectable, biodegradable, sets at ambient temperature, has both near neutral pHs and a large surface area [52,53]. These properties make self-setting calcium orthophosphate formulations to be very attractive candidates as drug carriers for therapeutic peptides [617], antibiotics [26,[618][619][620][621][622][623][624][625][626][627][628][629], anticancer [630][631][632][633][634] and anti-inflammatory agents [635,636], cytokines [637], hormones [638], bone morphogenetic proteins [488,[639][640][641][642][643] and other biologically active compounds [644][645][646][647][648][649][650][651]. For example, a -growth factor cement‖ has been reported [652].…”