A novel soluble lornoxicam-sodium chelate monohydrate with improved plasticity and tabletability.

Lornoxicam (LOR), a BCS II nonsteroidal anti-inflammatory drug, has been clinically utilized for moderate to severe acute pain management. However, it has poor water solubility and insufficient tabletability, leading to erratic absorption and challenge in tablet processability. This study reported a novel solid state of LOR (i.e., LOR sodium chelate monohydrate, LOR-Na·H2O) with significantly improved solubility, dissolution rate and tabletability. The prepared chelate (CCDC No.: 2125157) contains LOR-, Na+, and H2O in a molar ratio of 1:1:1, where Na+ ions bridged with O(5) of amide group, and N(2) of pyridine group on LOR-, as well as O(4) on H2O through coordination bonds. LOR-Na·H2O displayed a superior dissolution rate (5 âˆ¼ 465 folds) than commercial LOR due to its increased wettability (contact angle: 74.5° vs 85.6°) and lower solvation free energy (∼2-fold). In addition, the significant improvement in tabletability was caused by high plasticity and deformability, which was attributed to its special interlayer gliding with weak bonding interactions across layers but strong coordination bonding interactions within layers. The novel LOR-Na·H2O with significantly enhanced pharmaceutical performance offers a promising strategy for further product development.

Dry and Wet Mechanochemical Synthesis of Piroxicam and Saccharin Co-Crystals and Evaluation by Powder X-Ray Diffraction, Thermal Analysis and Mid- and Near- Infrared Spectroscopy.

The purpose of this study is to investigate the effects of dry and wet mechanochemical synthesis on piroxicam (PX) and saccharin (SA) mixtures. For this purpose, PX and SA mixtures prepared by wet mechanochemical processes using three solvents and by dry mechanochemical synthesis were evaluated by mid-and near-infrared spectroscopy, powder X-ray diffraction (PXRD), and differential scanning calorimetry (DSC). The mixtures of wet-type products were transformed into PX/SA 1:1 co-crystals. The effect of the solvent was key to the co-crystallization of PX and SA. The products from the dry process were transformed into the amorphous phase. For the sample of the amorphous mixture, two exothermic peaks due to crystallization were observed in the thermal analysis. Bulk PX was ground for the same number of times for transformation, but was not successfully transformed to the amorphous bulk; the same was observed for SA. It is suggested that the mutual existence of PX and SA promotes mutual amorphization.

A Promising Single Oral Disintegrating Tablet for Co-Delivery of Pitavastatin Calcium and Lornoxicam Using Co-Processed Excipients: Formulation, Characterization and Pharmacokinetic Study.

SIGNIFICANCE: Statins are an important class of drugs that help to control hyperlipidemia, and one of these statins recently used is pitavastatin calcium (PITA). Nevertheless, the most reported adverse effect of statins is myopathy. Therefore, combining statins with non-steroidal anti-inflammatory drugs (NSAIDs) as Lornoxicam (LORNO) can help in the management of statin-induced myopathy. PURPOSE: This study aimed to formulate and evaluate different oral disintegrating tablets (ODTs) containing PITA using different co-processed excipients. The best PITA-ODT was selected and reformulated with the addition of LORNO, forming a single ODT comprising both drugs. The pharmacokinetic parameters of PITA and LORNO in a single ODT were compared to those of the marketed products (Lipidalon® and Lornoxicam®). METHODS: Eight PITA-ODTs were prepared via direct compression. The prepared PITA-ODTs were evaluated for their weight variation, thickness, breaking force, friability, drug content, and wetting time (WT). In-vitro disintegration time (DT) and dissolution were also evaluated and taken as parameters for selection of the best formula based on the criteria of scoring the fastest DT and highest Q10 min. LORNO was added to the selected PITA-ODT, forming a single ODT (M1) comprising both drugs, which was subjected to an in-vivo pharmacokinetic study using rats as an animal model and liquid chromatography-mass spectrometry (LC-MS/MS) for analysis of both drugs in rat plasma. RESULTS: Results showed that all PITA-ODTs had acceptable physical properties in accordance with pharmacospecial standards. PITA-ODT prepared with Pharmaburst® (F2) had significantly (p<0.05) the fastest DT (6.66±1.52 s) and highest Q10 min (79.07±2.02%) and was chosen as the best formula. The in-vivo pharmacokinetic study of M1 formula showed higher percent relative bioavailability (%RB) of 286.7% and 169.73% for PITA and LORNO, respectively, compared with the marketed products. CONCLUSION: The single ODT comprising PITA and LORNO was promising for instant co-delivery of both drugs with higher %RB when compared with the marketed products.

Macroporous scaffold surface modified with biological macromolecules and piroxicam-loaded gelatin nanofibers toward meniscus cartilage repair.

Meniscus cartilage has poor self-healing capacity in the inner zone and its damage leads to articular cartilage degeneration. Here we have developed hybrid constructs using polycaprolactone (PCL) and polyurethane (PU) surface modified by gelatin (G), chitosan (C), and hyaluronic acid (H) biomacromolecules and piroxicam-loaded gelatin nanofibers (PCL/PU/GCH/P). The surface of constructs was crosslinked using EDC and NHS. The scaffolds were investigated by SEM, FTIR spectroscopy, swelling test, degradation rate, mechanical tests, and in vitro piroxicam release assay. Furthermore, the cell-seeded scaffolds were evaluated by SEM, viability assay, dapi staining, cell migration, proliferation, and gene expression of chondrocytes within these scaffolds. Finally, the animal study was performed in a rabbit model. Chondrocyte and rabbit adipose-derived mesenchymal stem cells (ASCs) from the infrapatellar fat pad (Hoffa's fat pad) were used. Swelling and degradation rate were increased in the modified scaffolds. Tensile and compressive Young's modulus also were near to human native meniscus tissue. The highest expression level of chondrocyte marker genes was observed for the PCL/PU/GCH scaffold. A significant regeneration was obtained in rabbits treated with ASCs-loaded PCL/PU/GCH/P scaffold after 3 months. The surface-modified scaffolds with or without ASCs could successfully accelerate meniscus regeneration and exhibit potential application in meniscus tissue engineering.

Piroxicam Loading onto Mesoporous Silicas by Supercritical CO2 Impregnation.

Piroxicam (PRX) is a commonly prescribed nonsteroidal anti-inflammatory drug. Its efficacy, however, is partially limited by its low water solubility. In recent years, different studies have tackled this problem and have suggested delivering PRX through solid dispersions. All these strategies, however, involve the use of potentially harmful solvents for the loading procedure. Since piroxicam is soluble in supercritical CO2 (scCO2), the present study aims, for the first time, to adsorb PRX onto mesoporous silica using scCO2, which is known to be a safer and greener technique compared to the organic solvent-based ones. For comparison, PRX is also loaded by adsorption from solution and incipient wetness impregnation using ethanol as solvent. Two different commercial mesoporous silicas are used (SBA-15 and Grace Syloid® XDP), which differ in porosity order and surface silanol population. Physico-chemical analyses show that the most promising results are obtained through scCO2, which yields the amorphization of PRX, whereas some crystallization occurs in the case of adsorption from solution and IWI. The highest loading of PRX by scCO2 is obtained in SBA-15 (15 wt.%), where molecule distribution appears homogeneous, with very limited pore blocking.

Co-delivery of norfloxacin and tenoxicam in Ag-TiO2/poly(lactic acid) nanohybrid.

A nanohybrid formulation of silver­titanium dioxide nanoparticles/poly(lactic acid) (Ag-TiO2/PLA) was designed for Norfloxacin/Tenoxicam (NOR/TENO) targeted delivery to maximize the bioavailability and minimize the side effects of the drugs. Ag-TiO2 nanoparticles were prepared via Stober method. NOR, TENO and a mixture of NOR/TENO (NT) were loaded onto Ag-TiO2 nanoparticles and coated by PLA via solution casting. The physical interaction between the drugs and carrier was confirmed by Fourier-transform infrared (FTIR) analysis. X-ray diffraction (XRD) demonstrated that Ag-TiO2 consists of a cubic phase of Ag with two phases of TiO2 (anatase and brookite). Ag nanoparticle fine spots coated with TiO2 were collected to form spheres averaging at 100 nm in size. In-vitro release behavior of drugs was studied at different pH (5.4, 7.4) and the release of drug from NT/Ag-TiO2/PLA was faster at pH 7.4. Gram-positive and Gram-negative bacteria were used to investigate antibacterial properties of the nanohybrid. Cytotoxicity of the nanohybrid using an MTT assay was studied against different tumor and normal cell lines. It was found that NT/Ag-TiO2/PLA has an excellent cytotoxic effect against various bacterial cells and tumor cell lines. In addition, antioxidant properties of the nanohybrids were tested using ABTS method and the nanohybrid showed moderate antioxidant activity.

Monitoring the Isothermal Dehydration of Crystalline Hydrates Using Low-Frequency Raman Spectroscopy.

Detection of the solid-state forms of pharmaceutical compounds is important from the drug performance point of view. Low-frequency Raman (LFR) spectroscopy has been demonstrated to be very sensitive in detecting the different solid-state forms of pharmaceutically relevant compounds. The potential of LFR spectroscopy to probe the in situ isothermal dehydration was studied using piroxicam monohydrate (PXM) and theophylline monohydrate (TPMH) as the model drugs. The dehydration of PXM and TPMH at four different temperatures (95, 100, 105, and 110 °C and 50, 60, 70, and 80 °C, respectively) was monitored in both the low- (20-300 cm-1) and mid-frequency (335-1800 cm-1) regions of the Raman spectra. Principal component analysis and multivariate curve resolution were applied for the analysis of the Raman data. Spectral differences observed in both regions highlighted the formation of specific anhydrous forms of piroxicam and theophylline from their respective monohydrates. The formation of the anhydrous forms was detected on different timescales (approx. 2 min) between the low and mid-frequency Raman regions. This finding highlights the differing nature of the vibrations being detected between these two spectral regions. Computational simulations performed were also in agreement with the experimental results, and allowed elucidating the origin of different spectral features.

Bilosomes as Promising Nanovesicular Carriers for Improved Transdermal Delivery: Construction, in vitro Optimization, ex vivo Permeation and in vivo Evaluation.

PURPOSE: The goal of this research was to enhance the transdermal delivery of lornoxicam (LX), using nanovesicular carriers composed of the bile salt sodium deoxycholate (SDC), soybean phosphatidyl choline (SPC) and a permeation enhancer limonene. METHODS: Thin-film hydration was the technique employed for the fabrication using a Box-Behnken design with three central points. The investigated factors were SPC molar concentration, SDC amount in mg and limonene percentage (%). The studied responses were percent entrapment efficiency (%EE), particle size (PS), polydispersity index (PDI), zeta potential (ZP), and in vitro drug release (after 2, 10 h). In order to obtain the optimum formula, numerical optimization by Design-Expert® software was used. Electing the optimized bilosomal formula was based on boosting %EE, ZP (as absolute value) and in vitro drug release, taking in consideration diminishing PS and PDI. Further assessment of the selected formula was achieved by transmission electron microscopy (TEM), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), stability testing, ex vivo skin permeation and deposition. The in vivo pharmacodynamics activities of the optimized formula were examined on male rats and mice and compared to that of the oral market product. RESULTS: The optimized bilosomal formula demonstrated to be nonirritant, with noticeably enhanced anti-inflammatory and antinociceptive activities. Superior in vivo permeation was proved by confocal laser scanning microscopy (CLSM). CONCLUSION: The outcomes demonstrated that bilosomes could improve transdermal delivery of lornoxicam.

Electrospun Gelatin Nanocontainers for Enhanced Biopharmaceutical Performance of Piroxicam: In Vivo and In Vitro Investigations.

BACKGROUND: Piroxicam exhibits low oral bioavailability, due to its meager solubility in water. The intent of this study was to ameliorate the bioavailability of the drug by employing a solubility-enhancing encapsulation technique. METHODS: Seven samples were formulated with piroxicam and gelatin using both solvent evaporation and electrospraying together. Evaluation of solubility and release rate in water and assessment of bioavailability in rats were carried out in comparison with piroxicam plain drug powder (PPDP). Other in vitro explorations were accomplished using powder X-ray diffraction analysis, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, and Fourier-transform infrared spectroscopy. RESULTS: All piroxicam-loaded gelatinnanocontainers (PLGNs) enhanced solubility and release of the payload in water. In particular, a PLGN formulation consisting of piroxicam and gelatin at a 1:8 (w:w) ratio presented about 600-fold the drug solubility of that shown by PPDP. Moreover, 85.12%±10.96% of the payload was released from this formulation in 10 minutes which was significantly higher than that dissolved from PPDP in 10 minutes (11.81%±5.34%). Drug content, drug loading, and encapsulation efficiency of this formulation were 93.41%±0.56%, 10.45%±0.06%, and 66.74%±6.87%, respectively. The drug loaded in PLGNs existed in the amorphous state, as confirmed by X-ray diffraction and differential scanning-calorimetry analyses, and was more stable when analyzed by thermogravimetric analysis. Moreover, Fourier-transform infrared spectroscopy analysis suggested nonexistence of any piroxicam-gelatin interaction in the formulation. In the scanning electron-microscopy image, PLGNs appeared as round, smooth particles, with particle size of <1,000 nm. Amelioration in bioavailability of piroxicam with the aforementioned PLGN formulation was fourfold that of PPDP. CONCLUSION: The PLGN formulation fabricated with piroxicam and gelatin at 1:8 (w:w) might be a promising system for enhanced biopharmaceutical performance of the drug.

Identification of hub genes and discovery of promising compounds in gastric cancer based on bioinformatics analysis.

Aim: To explore the mechanism of gastric carcinogenesis by mining potential hub genes and to search for promising small-molecular compounds for gastric cancer (GC). Materials & methods: The microarray datasets were downloaded from Gene Expression Omnibus database and the genes and compounds were analyzed by bioinformatics-related tools and software. Results: Six hub genes (MKI67, PLK1, COL1A1, TPX2, COL1A2 and SPP1) related to the prognosis of GC were confirmed to be upregulated in GC and their high expression was correlated with poor overall survival rate in GC patients. In addition, eight candidate compounds with potential anti-GC activity were identified, among which resveratrol was closely correlated with six hub genes. Conclusion: Six hub genes identified in the present study may contribute to a more comprehensive understanding of the mechanism of gastric carcinogenesis and the predicted potential of resveratrol may provide valuable clues for the future development of targeted anti-GC inhibitors.

Understanding Surface Interaction and Inclusion Complexes between Piroxicam and Native or Crosslinked ß-Cyclodextrins: The Role of Drug Concentration.

Drug concentration plays an important role in the interaction with drug carriers affecting the kinetics of release process and toxicology effects. Cyclodextrins (CDs) can solubilize hydrophobic drugs in water enhancing their bioavailability. In this theoretical study based on molecular mechanics and molecular dynamics methods, the interactions between ß-cyclodextrin and piroxicam, an important nonsteroidal anti-inflammatory drug, were investigated. At first, both host-guest complexes with native ß-CD in the 1:1 and in 2:1 stoichiometry were considered without assuming any initial a priori inclusion: the resulting inclusion complexes were in good agreement with literature NMR data. The interaction between piroxicam and a ß-CD nanosponge (NS) was then modeled at different concentrations. Two inclusion mechanisms were found. Moreover, piroxicam can interact with the external NS surface or with its crosslinkers, also forming one nanopore. At larger concentration, a nucleation process of drug aggregation induced by the first layer of adsorbed piroxicam molecules is observed. The flexibility of crosslinked ß-CDs, which may be swollen or quite compact, changing the surface area accessible to drug molecules, and the dimension of the aggregate nucleated on the NS surface are important factors possibly affecting the kinetics of release, which shall be theoretically studied in more detail at specific concentrations.

Biological and Spectroscopic Investigations of New Tenoxicam and 1.10-Phenthroline Metal Complexes.

In the present work, tenoxicam (H2Ten) reacted with Mn(II), Co(II), Ni(II), Cu(II) and Zn (II) ions in the presence of 1.10-phenthroline (Phen), forming new mixed ligand metal complexes. The properties of the formed complexes were depicted by elemental analyses, infrared, electronic spectra, proton nuclear magnetic resonance (1H NMR), mass spectrometry, thermogravimetric (TGA) and differential thermogravimetric (DTG) analysis, molar conductance and magnetic moment. IR spectra demonstrated that H2Ten acted as a neutral bidentate ligand, coordinated to the metal ions via the pyridine-N and carbonyl group of the amide moiety, and Phen through the nitrogen atoms. Kinetic thermodynamics parameters activation energy (E*), enthalpy of activation (ΔH*), entropy of activation (ΔS*), Gibbs, free energy (ΔG*) associated to the complexes have been evaluated. Antibacterial screening of the compounds was carried out in vitro against Clavibacter michiganensis, Xanthomonas campestris and Bacillus megaterium. Antifungal activity was performed in vitro against Monilinia fructicola, Penicillium digitatum and Colletotrichum acutatum. The possible phytotoxic effect of the studied compounds was also investigated on Solanum lycopersicum (tomatoes) and Lepidium sativum (garden cress) seeds. The anticancer activity was screened against cell cultures of HCT-116 (human colorectal carcinoma), HepG2 (human hepatocellular carcinoma) and MCF-7 (human breast adenocarcinoma).

Covalent polybenzimidazole-based triazine frameworks: A robust carrier for non-steroidal anti-inflammatory drugs.

Covalent triazine-based polymers (CTPs) are a new class of porous materials that can be used for the intercalation of therapeutic agents. The main purposes of designing new drug carriers include protecting them from degradation, enhancing their poor aqueous solubility, and investigating their controlled release properties. In this context, a novel polybenzimidazole-based CTP (BZ-CTP) was prepared by a solvothermal reaction between 4,4',4″-((1,3,5-triazine-2,4,6-triyl) tris(azanediyl)) tribenzoic acid (TCA) and 3,3'-diaminobenzidine. Piroxicam (PRX) and mefenamic acid (MFA) were loaded thoroughly into the CTP by using ultrasonication to form MFA-loaded CTP (MFA@BZ-CTP) and PRX-loaded CTP (PRX@BZ-CTP) with drug loading efficiencies of 49% and 53%, respectively. We attribute the increased loading efficiencies to the formation of π-π stacking forces between the aromatic rings present in the CTP structure and drugs. The in vitro release experiments were assessed in simulated physiological conditions using the dialysis method. Moreover, the release mechanisms were evaluated by Korsmeyer-Peppas kinetic studies and the obtained results showed excellent sustained releases of 81% after 96 h and 87% after 24 h for the PRX@BZ-CTP and MFA@BZ-CTP hybrids, respectively.

Detection of low dose of piroxicam polymorph in pharmaceutical tablets by surface-enhanced Raman chemical imaging (SER-CI) and multivariate analysis.

This study demonstrates, for the first time, the ability of surface-enhanced Raman chemical imaging (SER-CI) combined with multivariate analysis to detect low levels (0.1% (w/w)) of a polymorphic form in a pharmaceutical mixture. In the studied formulation, piroxicam was used as a model molecule to develop this approach. Piroxicam is a widely available non-steroidal anti-inflammatory drug, exhibiting an interesting case of polymorphism, with two most commonly observed forms (ß and α2). In this work, the SERS spectra of piroxicam polymorphic forms ß and α2 are presented. These forms showed clear spectral differences in terms of band position and intensity. From a crystallographic point of view, the difference of exaltation between both forms was correlated with a preferred orientation of crystallites of form α2 making its SERS detection difficult compared to form ß. A preferred orientation of the (1k0) crystallographic planes of α2 was demonstrated in samples, not promoting an appropriate molecular orientation onto the metallic surface. Additionally, a semi-quantitative approach using SER-CI combined with chemometric tools was developed enabling to detect crystallites of form ß below the detection limit of conventional Raman microscopy. The exaltation of the Raman signal in the presence of silver nanoparticles allowed a higher sensitivity and a reduction of the acquisition time by a factor of 6.

Sericin Inhibits Devitrification of Amorphous Drugs.

The purpose of the present investigation was to analyze devitrification of amorphous drugs such as lornoxicam, meloxicam, and felodipine in the presence of sericin. The binary solid dispersions comprising varying mass ratios of drug and sericin were subject to amorphization by spray drying, solvent evaporation, ball milling, and physical mixing. Further, obtained solid dispersions (SDs) were characterized by HPLC, ATR-FTIR, H1NMR, molecular docking, accelerated stability study at 40°C and 75 ± 2% RH (XRD and DSC), and in vitro dissolution studies. The HPLC analysis indicated no decomposition of the drugs during the spray drying process. From ATR-FTIR, NMR, and molecular docking study, it was revealed that H-bonding played a vital role in amorphous drug stabilization. An excellent devitrification inhibition was observed in case of lornoxicam (SDLS3) and meloxicam (SDMS3) SDs prepared by spray drying. On the other hand, spray-dried SD of felodipine (SDFS3) showed traces of microcrystals. The percent crystallinity of SDLS3, SDMS3, and SDFS3 was found to be 7.4%, 8.23%, and 18.31% respectively indicating adequate amorphization. The dissolution performance of SDLS, SDMS, and SDFS after 3 months showed > 85% than SDs prepared by other methods. Thus, sericin significantly inhibited crystallization and was responsible for amorphous state stabilization of pharmaceuticals.

Justification of Biowaiver and Dissolution Rate Specifications for Piroxicam Immediate Release Products Based on Physiologically Based Pharmacokinetic Modeling: An In-Depth Analysis.

A quantitative prediction of human pharmacokinetic (PK) profiles has become an increasing demand for the reduction of the clinical failure of drug formulations. The existing in vitro and in vivo correlation (IVIVC) methodology could achieve this goal, but the development of IVIVC for immediate release (IR) products is challenging. Herein, we report that for certain weakly acidic biopharmaceutical classification system (BCS) class II molecules (piroxicam, PIRO), physiologically based PK (PBPK) modeling could be used as a tool to quantitatively predict PK in beagle dogs and to conduct an interspecies extrapolation to humans. First, robust PBPK models were constructed in beagle dogs under both fasted and fed states. Then, a Z-factor model was integrated to assess the effect of in vitro dissolution rates on the in vivo PK performance, and the results illustrated that PIRO IR products had a much wider dissolution space than was anticipated by bioequivalence. In addition, the parameter sensitivity analysis (PSA) assay showed that good oral absorption was achieved only when the particle size was below 150 µm. Finally, the combined PBPK models were extrapolated to humans to specify a quality control strategy; this extrapolation constituted an extension of a biowaiver for PIRO IR formulations. The results showed that the developed method can be utilized to quantitatively predict human PK, which would be meaningful for future scale-up or postapproval changes.

Effect of casting solvent, film-forming agent and solubilizer on orodispersible films of a polymorphic poorly soluble drug: an in vitro/in silico study.

In the current work, a full factorial experimental design was utilized to formulate piroxicam into orodispersible films while investigating the effects of some formulation factors on the properties of the resulting films. These factors were (A) the casting solvent: water and acetone/water mixture; (B) the film-forming agent: HPMC K4M and Na-alginate; (C) the solubilization system: no solubilizer, L-arginine, poloxamer and L-arginine/poloxamer mixture. Sixteen formulation runs were prepared by solvent casting method to obtain 10 mg piroxicam dosage units. Drug particle size in the prepared formulations and dissolution efficiency at 30 min were selected as responses variables. Additionally, the prepared films from each formulation were evaluated for other characters as drug content, thickness, residual water…etc. A selected formulation was then evaluated for its in vivo disintegration, palatability and stability. Utilizing acetone in the casting solution, Na-alginate as film-forming agent or both of them resulted in formation of films with larger drug particles and slower dissolution. Combined use of L-arginine and poloxamer showed better drug dissolution than using each alone. HPMC was more favorable than Na-alginate regarding mechanical properties and moisture absorption. Films from the selected formulation showed fast in vivo disintegration and acceptable palatability. These films were stable for 6 months under accelerated storage conditions. According to the computer simulation using GastroPlus™, the in vitro/in vivo behavior of piroxicam in the tested formulation was similar to that of an immediate-release formulation containing BCS class I drug. The selected formulation is therefore would satisfy the WHO perquisites for applying the biowaiver.

Metal-Ligand Recognition Index Determination by NMR Proton Relaxation Study.

In this study, we developed and validated a new proposed parameter quantifying the interaction strength between natural and/or synthetic molecules with paramagnetic metal ions. The Metal ion Recognition Index, Miri, is a quantitative parameter to describe the proton environment and to define their involvement in the inner and/or outer sphere of the paramagnetic metal ion. The method is based on the analysis of NMR proton spin-lattice relaxation rates of a specific ligand in both the diamagnetic and paramagnetic conditions. The proposed procedure is also useful to calculate the ligand proton spin-lattice relaxation rate in the paramagnetic bound conditions, which is typically very difficult to determine experimentally. Miri was used to compare the ligand proton involvement toward different paramagnetic species, in particular the Copper(II)-Piroxicam system. Copper(II)-Piroxicam complex is one of the most active anti-inflammatory and anti-arthritic species. Miri provides an opportunity to improve our knowledge of metal-ligand complexes that play a fundamental role in bioinorganic interactions.

Proniosomal gel for transdermal delivery of lornoxicam: optimization using factorial design and in vivo evaluation in rats.

OBJECTIVE: Clinical utility of lornoxicam in oral therapy is primarily restricted by the low solubility and gastric adverse effects. This study evaluated the prospective of optimized proniosomal gel to improve the clinical efficacy of lornoxicam and compare with oral therapy. METHODS: Proniosomes were formulated by coacervation phase separation technique using span 60, lecithin and cholesterol. A four-factor three-level Box-Behnken design was used to evaluate the effect of amount of four independent variables; span 60 (X1), cholesterol (X2), lecithin (X3) and lornoxicam (X4) on response variables; vesicle size (Y1), entrapment efficiency (Y2) and transdermal flux (Y3). The selected proniosomal gel (F19) was characterized, and evaluated for the transdermal efficacy by ex vivo and in vivo experiments. RESULTS: Optimization study signifies that amount of formulation components (span 60, cholesterol, lecithin and lornoxicam) influence the vesicle size, entrapment efficiency and/or transdermal flux. Optimized formulation F19 exhibited nano size with high entrapment efficiency, adequate zeta potential, greater transdermal flux and better stability (at refrigerated conditions). The entrapment of lornoxicam in the bilayers of proniosome vesicles was confirmed by differential scanning calorimeter. Release profile of F19 was distinct (p < 0.001) from gel prepared using hydroxypropyl methylcellulose (control) and displayed steady lornoxicam release by Fickian diffusion. Transdermal administration of F19 significantly inhibited the carrageenan induced hind-paw edema in rats as compared to oral lornoxicam group. CONCLUSIONS: The data observed in this study demonstrated that the developed proniosomal gel (F19) improved the clinical efficacy of lornoxicam as compared to oral therapy. Graphical Abstract Proniosomal gel for transdermal delivery of lornoxicam: optimization using factorial design and in vivo evaluation in rats.

Simultaneous voltammetric sensing of levodopa, piroxicam, ofloxacin and methocarbamol using a carbon paste electrode modified with graphite oxide and ß-cyclodextrin.

A carbon paste electrode (CPE) was modified with graphite oxide (GrO) and ß-cyclodextrin (CD) to obtain a sensor for simultaneous voltammetric determination of levodopa (LD), piroxicam (PRX), ofloxacin (OFX) and methocarbamol (MCB). The morphology, structure and electrochemical properties of the functionalized GrO were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, contact angle measurements and cyclic voltammetry. Under the optimal experimental conditions, the sensor is capable of detecting LD, PRX, OFX and MCB by square wave voltammetry (SWV) at working potentials of +0.40, +0.60, +1.03 and + 1.27 V (versus Ag/AgCl), respectively. Response is linear from 1.0 to 20 µM for LD, from 1.0 to 15 µM for PRX, from 1.0 to 20 µM for OFX, and from 1.0 to 50 µM for MCB. The respective limits of detection are 65, 105, 89 and 400 nM. The method was successfully applied to the simultaneous determination of LD, PRX, OFX and MCB in (spiked) real river water and synthetic urine samples, and the results were in agreement with those obtained using a spectrophotometric method, with recoveries close to 100%. Graphical abstract Schematic presentation of a novel electroanalytical method employing a carbon paste electrode modified with graphite oxide and ß-cyclodextrin for the simultaneous determination of levodopa, piroxicam, ofloxacin and methocarbamol in urine and river water samples by square wave voltammetry.