Coumarin-Encapsulated Solid Lipid Nanoparticles as an Effective Therapy against Methicillin-Resistant Staphylococcus aureus.

Bacterial infections caused by antibiotic-resistant pathogens are a significant public health problem. This is because the transmission of infectious diseases is shifting, and new antibiotic-resistant strains of bacteria are emerging. The development of biofilms that are resistant to antibiotics poses another hurdle to drugs and treatment alternatives. Therefore, there is an urgent need to develop innovative strategies to effectively eliminate antibiotic-resistant microorganisms effectively. Natural coumarins have broad spectrum bioactivity and the potential for lower resistance. Coumarin is a secondary metabolite found in certain plants, fungi, and bacteria. It is highly effective against methicillin-resistant Staphylococcus aureus (MRSA). Therefore, coumarin can be used as an alternative to combat MRSA. However, most antibacterial agents lack selective targeting of pathological sites, limiting the efficacy of their antibacterial activity. Efficient MRSA treatments can be achieved through nanoparticle (NPs)-based targeted therapies. To address this challenge, a novel coumarin-loaded solid lipid nanocarrier for MRSA was developed to overcome this challenge. The developed systems exhibited a particle size of 138.5 ± 76.06 nm and a polydispersity index (PDI) of 0.245 ± 0.00. The zeta potential of coumarin-loaded SLNs was reported to be -22.2 ± 8.15 mV with a spherical shape. The encapsulation efficiency of coumarin was reported to be 63.09 ± 3.46% in the final formulation. The developed formulation was biocompatible with a minimum inhibitory concentration (MIC) of 1.08 µg/mL. This study suggests that coumarin-loaded SLNs can effectively treat MRSA infections.

Development of Gum-Acacia-Stabilized Silver Nanoparticles Gel of Rutin against Candida albicans.

Candida spp. is one of the most causative pathogens responsible for fungal infections. It is often a hospital-acquired form of sepsis with a very high number of deaths. Currently, the most effective anti-fungal agents are based on polyenes or echinocandins. However, long-term treatments or repeated use of these anti-fungals lead to therapy limitations. Current research is urgently needed to overcome existing challenges for antimicrobials from natural sources. This study aims to determine the anti-fungal activity of rutin, which has the advantage of increasing the therapeutic value. Because of its low solubility in water and oils, rutin is limited in use. To address these constraints, we encapsulated rutin in a nanocarrier system. Silver nanoparticles (SNPs) and gum acacia (GAs) are emerging as attractive components and are widely studied as biologically safe nanomaterials/carrier systems for various drugs. Still, they are barely investigated as nano-sized vectors for the targeted delivery of rutin. In the present work, GA stabilised SNPs of rutin were successfully formulated and evaluated. It was later incorporated into carbapol 940 gels and formed SNP gels. Rutin-SNPs were developed with a consistent size in the nano range of 59.67 ± 44.24 nm in size, 0.295 ± 0.014 polydispersity index (PDI), and -11.2 ± 6.66 mV zeta potential. The drug released was found to be 81. 26 ± 4.06% in 600 min by following zero-order kinetics. The rutin-SNP gel showed considerable activity against C. albicans skin candidiasis at MIC 1.56 g/mL. The developed formulation was biocompatible. This first-ever interdisciplinary study suggests that the rutin-SNPs gel could play a vital role in drug resistance in this fungal pathogen.

Enhancing Ocular Bioavailability of Ciprofloxacin Using Colloidal Lipid-Based Carrier for the Management of Post-Surgical Infection.

Conjunctivitis and endogenous bacterial endophthalmitis mostly occurred after ophthalmic surgery. Therefore, the present study aimed to maximize the ocular delivery of ciprofloxacin (CPX) using colloidal lipid-based carrier to control the post-surgical infection. In this study, CPX was formulated as ophthalmic liposomal drops. Two different phospholipids in different ratios were utilized, including phosphatidylcholine (PC) and dimyrestoyl phosphatidylcholine (DMPC). The physiochemical properties of the prepared ophthalmic liposomes were evaluated in terms of particle size, entrapment efficiency, polydispersity index, zeta potential, and cumulative CPX in-vitro release. In addition, the effect of sonication time on particle size and entrapment efficiency of CPX ophthalmic drops was also evaluated. The results revealed that most of the prepared formulations showed particle size in nanometer size range (460-1047 nm) and entrapment efficiency ranging from 36.4-44.7%. The antibacterial activity and minimum inhibitory concentration (MIC) were investigated. Ex vivo antimicrobial effect of promising formulations was carried out against the most common causes of endophthalmitis microorganisms. The pharmacokinetics of the prepared ophthalmic drops were tested in rabbit aqueous humor and compared with commercial CPX ophthalmic drops (Ciloxan®). Observed bacterial suppression was detected in rabbit's eyes conjunctivitis with an optimized formulation A3 compared with the commercial ophthalmic drops. CPX concentration in the aqueous humor was above MIC against tested bacterial strains. The in vivo data revealed that the tested CPX drops showed superiority over the commercial ones with respect to peak aqueous humor concentration, time to reach peak aqueous humor concentration, elimination rate constant, half-life, and relative bioavailability. Based on these results, it was concluded that the prepared ophthalmic formulations significantly enhanced CPX bioavailability compared with the commercial one.

Combining Normal/Reversed-Phase HPTLC with Univariate Calibration for the Piperine Quantification with Traditional and Ultrasound-Assisted Extracts of Various Food Spices of Piper nigrum L. under Green Analytical Chemistry Viewpoint.

Due to unavailability of sustainable analytical techniques for the quantitation of piperine (PPN) in food and pharmaceutical samples, there was a need to develop a rapid and sensitive sustainable analytical technique for the quantitation of PPN. Therefore, the current research presents a fast and highly sensitive normal/reversed-phase high-performance thin-layer chromatography (HPTLC) technique with classical univariate calibration for the quantitation of PPN in various food spices of black pepper with traditional (TE) and ultrasound-assisted extracts (UBE) of various food spices of Piper nigrum L. under green analytical chemistry viewpoint. The amount of PPN in TE of four different spices of black pepper-namely BPMH, BPLU, BPSH, and BPPA-was found to be 309.53, 304.97, 282.82, and 232.73 mg g-1, respectively using a sustainable normal-phase HPTLC technique. However, the amount of PPN in UBE of BPMH, BPLU, BPSH, and BPPA was recorded as 318.52, 314.60, 292.41, and 241.82 mg g-1, respectively using a sustainable normal phase HPTLC technique. The greenness of normal/reversed-phase HPTLC technique was predicted using AGREE metric approach. The eco-scale was found to be 0.90, suggested excellent greenness of normal/reversed-phase technique. UBE of PPN was also found to be superior over TE of PPN. Overall, the results of this research suggested that the proposed normal/reversed-phase densitometry technique could be effectively used for the quantitation of PPN in food and pharmaceutical samples.

Formulation and in vitro and in vivo evaluation of surfactant-stabilized mucoadhesive nanogels for vaginal delivery of fluconazole.

Surfactant-stabilized mucoadhesive nanogels (NGs) for vaginal delivery of fluconazole (FLZ) were studied and evaluated in this work. FLZ-NG formulations were prepared using two different types of mucoadhesive polymers, Carbopol 934 (Ca934) and Pluronic F-127 (PF127). A rheology study revealed a non-Newtonian pseudoplastic flow behavior (shear thinning) in the prepared NGs. The viscosity of Ca934 NG (0.47 Pa s) was much lower compared to the PF127 NG (6.10 Pa s). The rheology study results correlated well with the in vitro FLZ release profile from the NG formulations. A pH study (pH = 3.90-4.90) revealed that the formulations were physiologically suitable for vaginal application, to avoid the irritation of the vaginal mucosa. Finally, in vitro and in vivo antimicrobial tests were performed. FLZ incorporated into the Ca934 gel had the strongest antimicrobial effect, with a mean inhibition zone of 24 ± 1.6 mm. Based on these results, it was concluded that the mucoadhesive NG incorporating FLZ resulted in a sustained release and enhanced antimicrobial effect, which would enhance and prolong the therapeutic effects of vaginally delivered FLZ.

The Interaction of Schistosoma Japonicum Glutathione Transferase with Cibacron Blue 3GA and its Fragments.

BACKGROUND: The 26kDa glutathione transferase (GST, EC 2.5.1.18) from Schistosoma japonicum (SjGST) is recognized as the major detoxification enzyme of S. japonicum, a pathogenic helminth causing schistosomiasis. OBJECTIVE: In the present study, the interaction of the chlorotriazine dye Cibacron blue 3GA (CB3GA) and its structural analogues with SjGST was investigated. The work aimed to shed light on the non-substrate ligand-binding properties of the enzyme. METHODS: Kinetic inhibition analysis, affinity labelling experiments and molecular modelling studies were employed. RESULTS: The results showed that CB3GA is a potent inhibitor (IC50 0.057 ± 0.003 µM) towards SjGST. The enzyme was specifically and irreversibly inactivated by the dichlorotriazine-analogue of CB3GA (IC50 0.190 ± 0.024 µM), following a biphasic pseudo-first-order saturation kinetics with approximately 1 mol of inhibitor per mol of the dimeric enzyme being incorporated. All other monochlorotriazine analogues behave as reversible inhibitors with lower inhibition potency (IC50 5.2-82.3 µM). Kinetic inhibition studies, together with molecular modelling and molecular dynamics simulations, established that the CB3GA binding site overlaps both the G- and H-sites. Both hydrophobic/ polar interactions, as well as steric effects, have decisive roles in determining the inhibitory strength of CB3GA and its analogues. CONCLUSION: The results of the present study might be useful in future drug design and development efforts towards SjGST.

Development of Lipomer Nanoparticles for the Enhancement of Drug Release, Anti-microbial Activity and Bioavailability of Delafloxacin.

Delafloxacin (DFL) is a novel potent and broad-spectrum fluoroquinolone group of antibiotics effective against both Gram-positive and negative aerobic and anaerobic bacteria. In this study, DFL-loaded stearic acid (lipid) chitosan (polymer) hybrid nanoparticles (L-P-NPs) have been developed by single-emulsion-solvent evaporation technique. The mean particle size and polydispersity index (PDI) of optimized DFL-loaded L-P-NPs (F1-F3) were measured in the range of 299-368 nm and 0.215-0.269, respectively. The drug encapsulation efficiency (EE%) and loading capacity (LC%) of DFL-loaded L-P-NPs (F1-F3) were measured in the range of 64.9-80.4% and 1.7-3.8%, respectively. A sustained release of DFL was observed from optimized DFL-loaded L-P-NPs (F3). Minimum inhibitory concentration (MIC) values of the DFL-loaded L-P-NPs (F3) appeared typically to be four-fold lower than those of delafloxacin in the case of Gram-positive strains and was 2-4-fold more potent than those of delafloxacin against Gram-negative strains. The pharmacokinetic study in rats confirmed that the bioavailability (both rate and extent of absorption) of DFL-loaded L-P-NPs was significantly higher (2.3-fold) than the delafloxacin normal suspension. These results concluded that the newly optimized DFL-loaded L-P-NPs were more potent against both Gram-positive and negative strains of bacteria and highly bioavailable in comparison to delafloxacin normal suspension.

Utilization of gel electrophoreses for the quantitative estimation of digestive enzyme papain.

SDS-PAGE densitometric method for analysis of papain in pharmaceutical formulations was developed and validated for the first time. Standard and samples were mixed with SDS sample buffer and denatured at 95 °C for 5 min and the gel was run at 20 mA and 200 V for 30-40 min in SDS-PAGE buffer. Gels were stained in Coomassie blue solution and distained by 5% methanol and 10% acetic acid. Destained gels were imaged and analyzed using the ChemiDoc™ XRS+ System. Bands of papain appeared at Rf value 0.78 ± 0.03 corresponding to molecular weight 23406 Da between proteins with molecular weight 31,000 and 21,500 Da of the broad range protein standard. The generated calibration curve was used for quantitative estimation of papain in pharmaceutical formulations. The developed method was validated for precision, accuracy, specificity and robustness as described by the ICH guidelines. The proposed method gives an alternative approach for enzymes and protein analysis.

New microbial source of the antifungal allylamine "Terbinafine".

The isolated active compound "F12" from the culture media of the Streptomyces sp. KH-F12 was identified using different spectroscopic techniques. Both 1D- and 2D-NMR as well as HRESIMS were utilized to characterize the structure of the isolated compound. 'F12" was found to be the known systemic antifungal drug terbinafine marketed under the name "Lamisil". Full analysis of the COSY, HSQC and HMBC enables the full assignment of proton and carbon atoms. Terbinafine is a synthetic allylamine and is reported here for the first time from natural source.