Formulation and development of embelin liquisolid systems using quality by design approach

Embelin-loaded chitosan gold nanoparticles interact synergistically with ciprofloxacin by inhibiting efflux pumps in multidrug-resistant Pseudomonas aeruginosa and Escherichia coli

A global upsurge in emergence and spread of antibiotic resistance (ABR) in bacterial populations is a serious threat for human health. Unfortunately, ABR is no longer confined to nosocomial environments and is frequently reported from community microbes as well. The ABR is resulting in shrinking potent antibiotics pool and thus necessitating novel and alternative therapies and therapeutics. Current investigation was aimed to assess the synergistic potential of a synthesized, phytomolecule-loaded, polysaccharide-stabilized metallic nanoparticles (NPs) against Pseudomonas aeruginosa (PA) and Escherichia coli (EC) isolated from river waters. ABR profiling of these strains characterized them as multidrug resistant (MDR). Synthesized embelin (Emb, isolated from Embelia tsjeriam-cottam)-loaded, chitosan-gold (Emb-Chi-Au) NPs were assessed for their potential synergistic activity with ciprofloxacin (CIP) via checker-board assay and time-kill curve analysis. The NPs reduced the minimal inhibitory concentration (MIC) of CIP by 16- and 4-fold against MDR PA (PA-r) and EC (EC-r) strains, respectively. Fractional inhibitory concentration (FIC) indices with ≤0.5 values confirmed the synergy between the Emb-Chi-Au NPs and CIP, which was further confirmed at ½ MICs in both PA-r and EC-r via time-kill curve analysis. In order to decipher the mode of action, efflux pump inhibitory effects of Emb-Chi-Au NPs were evaluated in terms of the increase in the EtBr mediated fluorescence in control versus NP-treated MDR strains. Molecular docking based in silico simulations were used to predict the interactions between Emb and the active sites of the efflux pump related proteins in PA-r (MexA, MexB and OprM) and EC-r (AcrA, AcrB and TolC), which revealed the probable bond formation between Emb and respective amino acid residues.

The importance of the coating material type and amount in the preparation of liquisolid systems based on magnesium aluminometasilicate carrier

Albeit the preparation of liquisolid systems represents an innovative approach to enhance the dissolution of poorly soluble drugs, their broader utilization is still limited mainly due to the problematic conversion of the liquid into freely flowing and readily compressible powder. Accordingly, the presented study aims to determine the optimal carrier/coating material ratio (R value) for formulations based on magnesium aluminometasilicate (NUS2) loaded with polyethylene glycol 400. Four commercially available colloidal silica were used as coating materials in nine different R values (range of 5 - 100). The obtained results suggested that the higher R value leads to the superior properties of powder mixtures, such as better flowability, as well as compacts with higher tensile strength and lower friability. Moreover, it was observed that the type of coating material impacts the properties of liquisolid systems due to the different arrangement of particles in the liquisolid mixture. To confirm the noted dependency of R value and coating material type, the one- and two-way ANOVA, linear regression and principal component analysis (PCA) techniques were performed. In addition, a comparison of results with the properties of loaded NUS2 itself revealed that LSS with sufficient properties may be prepared even without the coating material.

Formulation and in vitro evaluation of self-nanoemulsifying liquisolid tablets of furosemide

Self-nanoemulsifying drug delivery systems (SNEDDS) were used to enhance the dissolution rate of furosemide as a model for class IV drugs and the system was solidified into liquisolid tablets. SNEDDS of furosemide contained 10% Castor oil, 60% Cremophor EL, and 30% PEG 400. The mean droplets size was 17.9 ± 4.5 nm. The theoretical model was used to calculate the amounts of the carrier (Avicel PH101) and coating materials (Aerosil 200) to prepare liquisolid powder. Carrier/coating materials ratio of 5/1 was used and Ludipress was added to the solid system, thus tablets with hardness of 45 ± 2 N were obtained. Liquisolid tablets showed 2-folds increase in drug release as compared to the generic tablets after 60 min in HCl 0.1 N using USP apparatus-II. Furosemide loaded SNEDDS tablets have great prospects for further in vivo studies, and the theoretical model is useful for calculating the adequate amounts of adsorbents required to solidify these systems.