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This study provides useful information for the development of βLAP dosage forms, their storage, manipulation and quality control.

The morphology and dimensions of bioactive materials are essential attributes to promote tissue culture. Bioactive materials with nanofibrous structure have excellent potential to be used as bone-defect fillers, since they mimic the collagen in the extracellular matrix. On the other hand, bioactive glasses with applications in regenerative medicine may present antibacterial properties, which depend on glass composition, concentration and the microorganisms tested. Likewise, their morphology may influence their antibacterial activity too. In the present work, the laser-spinning technique was used to produce bioactive glass nanofibers of two different compositions: 45S5 Bioglass® and ICIE16M, bioactive glass doped with zinc and strontium. Their antibacterial activity against Staphylococcus aureus was tested by culturing them in dynamic conditions. Bacterial growth index profiles during the first days of experiment can be explained by the variations in the pH values of the media. The bactericidal effect of the doped nanofibers at longer times is justified by the release of zinc and strontium ions. Cytotoxicity was analyzed by means of cell viability tests performed with BALB/3T3 cell line.

The aim of this work is to analyze the effect of cyclodextrin (CD) complexation on the solubilization and stabilization of sodium dicloxacillin in acid aqueous solutions. The effect of four cyclodextrins alpha-, beta-, gamma- and hydroxypropyl-beta-CD was studied. Phase solubility diagrams obtained are AL or BS type, depending on the cyclodextrin used and on the pH of the solution. The highest stability constants of the inclusion complexes are obtained with gamma-CD at pH 1 and 2 and HPbeta-CD at pH 3. The structure of the inclusion complex in solution is characterized by nuclear magnetic resonance (1H-NMR). This study suggests that the 7-oxo-4-thia-1-azabicyclo group is located in the CD cavity. Nevertheless, molecular modelling calculations predict two different orientations of dicloxacillin in the gamma-CD cavity in vacuum and in aqueous solution. In vacuum, the results predict the inclusion of the dichlorophenyl ring of dicloxacillin instead of 7-oxo-4-thia-1-azabicyclo group into the gamma-CD cavity. However, the results are different in aqueous solution and this conformation is confirmed by the NMR study. The effect of gamma-CD and HPbeta-CD in the stability of the drug in solution was studied. The degradation of sodium dicloxacillin in solution follows a pseudo-first-order kinetics and the cyclodextrin do not change this fact. Both cyclodextrins increase the stability of the drug but the efficacy is higher with gamma-CD.

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