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Over the last few years, among controlled-release delivery systems, multivesicular liposomes (MVLs) have attracted attention due to their unique benefits as a loco-regional drug delivery system. Considering the clinical limitations of the current treatment strategies for osteomyelitis, MVLs can be a suitable carrier for the local delivery of effective antibiotics. This study aimed to prepare vancomycin hydrochloride (VAN HL) loaded MVLs using the active loading method which to the best of our knowledge has not been previously reported. Empty MVLS were prepared by the double emulsion (w/o/w) method and VAN HL was loaded into the prepared liposomes by the ammonium gradient method. After full characterization, the release profile of VAN HL from MVLs was assessed at two different pH values (5.5 and 7.4), and compared with the release profile of the free drug and also passively loaded MVLs. In vitro antimicrobial activities were evaluated using the disc diffusion method. Our results demonstrated that the encapsulation efficiency was higher than 90% in the optimum actively loaded MVL. The free VAN HL was released within 6-8 h, while the passively loaded MVLs and the optimum actively loaded MVL formulation released the drug in 6 days and up to 19 days, respectively. The released drug showed effective antibacterial activity against osteomyelitis-causing pathogens. In conclusion, the prepared formulation offered the advantages of sustained-release properties, appropriate particle size as well as being composed of biocompatible materials, and thus could be a promising candidate for the loco-regional delivery of VAN HL and the management of osteomyelitis.

Additional file 1. The Synthetic procedures and spectral data of intermediates of 3-6. Antimicrobial susceptibility assay. Assessment of anti-H. pylori activity. The MTT assay of selected compounds 7, 17, 18 and 29. The in silico toxicity evaluation results of target compounds. Table S1 insilico toxicity risk assessment of synthesized commpounds.

The aim of this study is to investigate the novel application of a ‎handheld near infra-red spectrophotometer coupled with classification methodologies as a screening approach in detection of adulterated lime juices. For this purpose, a miniaturized near infra-red spectrophotometer (Tellspec®) in the spectral range of 900–1700 nm was used. Three diffuse reflectance spectra of 31 pure lime juices were collected from Jahrom, Iran and 25 adulterated juices were acquired. Principal component analysis was almost able to generate two clusters. Partial least square discriminant analysis and k-nearest neighbors algorithms with different spectral preprocessing techniques were applied as predictive models. In the partial least squares discriminant analysis, the most accurate prediction was obtained with SNV transforming. The generated model was able to classify juices with an accuracy of 88% and the Matthew’s correlation ‎coefficient ‎value of 0.75 in the external validation set. In the k-NN model, the highest accuracy and Matthew’s correlation ‎coefficient in the test set (88% and 0.76, respectively) was obtained with multiplicative signal correction followed by 2nd-order derivative and 5th nearest neighbor. The results of this preliminary study provided promising evidence of the potential of the handheld near infra-red spectrometer and machine learning methods for rapid detection of lime juice adulteration. Since a limited number of the samples were used in the current study, more lime juice samples from a wider range of variability need to be analyzed in order to increase the robustness of the generated models and to confirm the promising results achieved in this study.

A series of hydroxyl semicarbazone derivatives of substituted diaryl ketones and acetophenones were synthesized and their structures were confirmed by analytical and spectroscopic methods including elemental analysis, infrared and nuclear magnetic resonance spectroscopy. The derivatives were prepared by a condensation reaction between N-hydroxy semicarbazide and substituted diaryl ketones or acetophenones leading to the desired hydroxysemicarbazones with excellent purity. The synthesized hydrazones were then evaluated for their inhibitory activity against bacterial strains including S. aureus, E. Coli, P. aeruginosa, K. pneumonia and M. luteus. Among the tested derivatives, compounds 2, 6 and 7 exhibited the highest bioactivity. Analysis of the activity data suggests that hydrophilicity is an important factor for the bioactivity of compounds 2 and 6 and also their selectivity over the gram-negative bacteria.

DETERMINATION OF STREPTOKINASE ACTIVITY IS USUALLY ACCOMPLISHED THROUGH TWO ASSAY METHODS: a) Clot lysis, b) Chromogenic substrate assay. In this study the biological activity of two streptokinase products, namely Streptase®, which is a native product and Heberkinasa®, which is a recombinant product, was determined against the third international reference standard using the two forementioned assay methods. The results indicated that whilst the activity of Streptase® was found to be 101 ± 4% and 97 ± 5% of the label claim with Clot lysis and Chromogenic substrate assay respectively, for Heberkinasa® the potency values obtained were 42 ± 5% and 92.5 ± 2% of the label claim respectively. To shed some light on the reason for this finding, the n-terminal sequence of the streptokinase molecules present in the two products was determined. The results showed slight differences in the amino acid sequence of the recombinant product in comparison to the native one at the amino terminus. This finding supports those of other workers who found that n-terminal sequence of the streptokinase molecule can have significant effect on the activity of this protein.

A series of hydroxysemicarbazone derivatives of substituted diaryl ketones and acetophenones were synthesized and their structures were confirmed by analytical and spectroscopic methods including elemental analysis, infrared and nuclear magnetic resonance spectroscopy. The derivatives were prepared by a condensation reaction between N-hydroxysemicarbazide and substituted diaryl ketones or acetophenones leading to the desired hydroxysemicarbazones with excellent purity. The synthesized hydrazones were then evaluated for their inhibitory activity against bacterial strains including S. aureus, E. Coli, P. aeruginosa, K. pneumonia and M. luteus. Among the tested derivatives, compounds 2, 6 and 7 exhibited the highest bioactivity. Analysis of the activity data suggests that hydrophilicity is an important factor for the bioactivity of compounds 2 and 6 and also their selectivity over the gram-negative bacteria.