New injectable formulation for the treatment of osteomyelitis

Introduction: Bone infections, such as osteomyelitis, are difficult to treat through traditional therapy, as antibiotics administered systemically, have difficulty reaching the site of infection, also due to poor vascularization of the bone tissue and, consequently, the drug is not able to reach the local concentrations necessary to eradicate the bacterium which is additionally protected by the Biofilm [1]. The same problems related to poor vascularization are observed with the intravenous administration of these drugs. For these reasons, an injectable formulation able to adhere to bone tissue, which releases the drug in a controlled and targeted manner and which is able to promote the resorption of necrotic bone, would be ideal for therapy in the treatment of bone infection. and its replacement with the growth of new bone. Methods: A formulation based on a biodegradable polymer capable of delivering Vancomycin Hydrochloride has been developed for the treatment of microbial infections in osteomyelitis. The peculiarity of this system is that it is an easily injectable liquid capable of giving rise to solid microparticles at the injection site. The particles were characterized for shape, size and drug release rate; their biodegradability in a simulated physiological environment was also evaluated. The antibacterial activity against a clinical strain of Staphylococcus aureus isolated from a surgical wound was evaluated on samples taken from day 0 to 60. The effect of the drug released on day 0 on J774-A1 macrophage cells of murine origin was also evaluated [2]. Results & Discussions: The formulation is capable of releasing Vancomycin in a controlled manner over 60 days. No bacterial growth was observed from day 0 to 45. On the 60th day, a Minimum Bactericidal Concentration equal to 0.5% V / V was detected. Cellular suffering of J774-A1 was observed post-treatment with S. aureus and the drug released. Conclusions: From the first data obtained, the formulation developed appears to have good injectability and allows the administration of Vancomycin locally, in therapeutically effective doses. Key words: Vancomycin,osteomyelitis, injectable formulation, microbial infections References 1. Uskoković V, Desai TA. In vitro analysis of nanoparticulate hydroxyapatite/chitosan composites as potential drug delivery platforms for the sustained release of antibiotics in the treatment of osteomyelitis. J Pharm Sci. 2014 Feb;103(2):567-79. 2. Amorese V, Donadu M, Usai D, Sanna A, Milia F, Pisanu F, Molicotti P, Zanetti S, Doria C. In vitro activity of essential oils against Pseudomonas aeruginosa isolated from infected hip implants. J Infect Dev Ctries. 2018 Nov 30;12(11):996-1001.