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In the present study, Lornoxicam immediate-release tablets were formulated using different types of selected binders and disintegrants and their effect on the dissolution rate was evaluated. The binding agents used were sucrose, acacia, gelatin, polyvinyl pyrrolidone (PVP), methylcellulose (MC), and hydroxypropyl methylcellulose (HPMC). Dry potato starch, starch paste (SP), and microcrystalline cellulose (MCC) were used as disintegrants, and sodium starch glycolate (SSG) was used as super-disintegrant. The wet granulation technique was used in the preparation of Lornoxicam tablets and was then evaluated for different parameters of pre-compression such as bulk density, tapped density, angle of repose, Carr's index, and Hausner's ratio, and post-compression parameters such as weight variation, hardness, friability, time of disintegration, drug content, and in vitro dissolution studies. Based on Dissolution efficiency (DE)(30%)min values, the order of performance of binders was found to be HPMC-SSG (LX1) >PVP-SSG (LX3)>SP-SSG (LX4). Among the tablet formulations (LX1-LX7), formulations LX3 and LX4 exhibited promising t50% and t70% of 10.5 min and 21 min respectively. DE(30%)min was higher in LX4 formulation, which showed a DE of 50.13 min. The regression coefficient 'r' values were observed, and it was found in the range of 0.9484 to 0.9964, indicating first-order drug release kinetics from all the formulations. [ABSTRACT FROM AUTHOR]

Aim: In the present study, mucoadhesive bilayer buccal tablets of furosemide were fabricated with the objective of avoiding first-pass metabolism and enhancing the bioavailability along with reducing the dosing frequency. Methodology: Direct compression method was used to prepare bilayer buccal tablets of furosemide, with a combination of polymers such as xanthan gum, karaya gum, and guar gum along with Carbopol 934-P and ethylcellulose as the backing layer. In order to provide a unidirectional drug delivery to the mucosa and for drug loss avoidance that occurs when there is a washout with saliva, the bilayer structure design was used. Physical and biological parameters were measured for the designed tablets. Results: FXG1 formulation containing xanthan gum, 1% and 2 % w/w of Carbopol 934p of matrix layer, and mannitol (15% w/w of matrix layer) used as a channeling agent was found to be assuring. This formulation exhibited 82.98% drug release in 8 h along with an acceptable strength of bioadhesion (5.40 g). Short-term stability studies on this formulation showed that no significant changes in drug content and dissolution characteristics existed (p<0.05). IR spectroscopic studies showed the absence of any drug-excipient interactions. The drug release was of zero order, whereas the value for release exponent (n) ranged from 0.787 to 1.063 which demonstrated a diffusion control super case II. Conclusion: The prepared buccal tablets of furosemide persisted in the buccal cavity longer, indicating that mucoadhesive tablets of furosemide have a good potential for the treatment of edema and hypertension. [ABSTRACT FROM AUTHOR]

The present work aims to improve patient compliance with fast dissolving lorazepam tablets by the direct compression procedure. The method used crospovidone and croscarmellose sodium (2-8% weight by weight (w/w) as super-disintegrants in solitary as well as disintegrating mixtures (i.e., crospovidone-croscarmellose sodium, crospovidone-sodium starch glycolate), and to enhance the mouth feel, directly compressible mannitol was used. In the prepared tablet formulations, lorazepam estimates were performed Ultraviolet(UV)/ Visible spectroscopic method at 231 nm. The preparation formulations were further assessed for friability, hardness, wetting time, water absorption, drug content uniformity and in vitro dispersion time. Based on the in-vitro dispersion time of around 12-42 s, in vitro drug release patterns (6.8 phosphate buffer), stability studies (3 months; at 40 °C/75% relative humidity) and drug excipient interactions (Infrared(IR) spectroscopy) were tested for promising formulations. The formulation (containing disintegrant blends of 2% w/w crospovidone and 4% w/w croscarmellose sodium) emerged as the overall best formulation among all the promising formulations. Stability studies on the promising formulation indicated that the drug content and the time of dispersion in vitro were not significantly changed. [ABSTRACT FROM AUTHOR]

Co-processed excipients were developed by the spray drying method. In this method, MCC : Aerosil : Fenugreek seed mucilage in different ratios (88:2:10, 90:2:8 and 92:2:6) were used. The prepared excipients were evaluated for compressibility index, that is Carr's index, Hausner's ratio, and flow properties, which is the angle of repose in comparison with physical mixture of the excipients. The angle of repose of co-processed excipients was found to be <30o, which describes a good flow in comparison to the physical mixture of the excipients, due to micronization, a very regular particle size is achieved. Carr's index was found to be in the range of 11.00-13.80% and Hausner's ratio was found to be in the range of 1.00-1.16. Fast dissolving tablets of Repaglinide were prepared using the above novel co- processed excipients and evaluated for pre-compression and post-compression parametres. Among the tablets prepared, the novel co-processed formulations MCC : Aerosil : Fenugreek seed mucilage in 88:2:10 ratio was found to be promising and showed a dispersion time of approximately 37.66 seconds. The wetting time was found to be 35.66 seconds, which facilitated its faster dispersion in the mouth. Stability studies of promising formulations indicated that there were no significant changes in the drug content and in vitro dispersion time. IR-spectroscopic studies indicated that there were no drug-excipient interactions. It can be concluded from the present work that novel co-processed excipients used in repaglinide fast dissolving tablets were found to be superior in flow characteristics in comparison with the physical mixture of the same excipients. [ABSTRACT FROM AUTHOR]

BODIPY derivative, SF-1, exclusively shows a fluorescence ON response to HOCl and images endogenously generated HOCl in RAW 264.7 macrophages. Widefield and super resolution structured illumination microscopy images confirm localization in the Golgi complex and lysosomes, and hence specifically detects HOCl generated in these organelles. SF-1 is compatible with 3D-SIM imaging of individual cells. [ABSTRACT FROM AUTHOR]

New BODIPY derivatives (dyes 1 and 2) with either catechol or resorcinol functionality, respectively, for anchoring to nanostructured (NS) TiO2 surfaces were synthesized. Extended conjugation at one of the two pyrrole rings at the C3 position helped us to achieve the desired control in tuning the optical and redox properties of the BODIPY based dye molecules. Relative emission quantum yields (Φem1 = ∼52 ± 2% and Φem2 = 54 ± 2%) were found to be much higher in a polar aprotic solvent (acetonitrile) and substantially lower for dye 1 in a polar protic solvent. Steady state optical absorption studies revealed the formation of a strong charge transfer complex between dye 1 and NS-TiO2, while this interaction was much weaker for dye 2. Transient absorption studies were carried out for 1/NS-TiO2 and 2/NS-TiO2 systems following excitation with a laser source of 400 nm to understand the charge transfer dynamics. The results of the transient absorption spectral studies helped us to elucidate the role of anchoring functionality in influencing the dynamics of interfacial electron transfer and charge recombination processes on an ultrafast timescale. [ABSTRACT FROM AUTHOR]

The synergistic effect of oxygen, light, and photosensitizer (PS) has found applications in medicine for the treatment of cancer through photodynamic therapy (PDT). Induction of apoptosis to cancerous cells will prevent tumor metastasis that spreads cancer cells to the neighboring organs/tissues. Herein, we report the two apoptotic Ru(ii)–polypyridyl complexes that are functionalized with pendant amino acid moieties tyrosine (1) and tryptophan (2), respectively. These two water soluble complexes were found to interact strongly (K1a = (1.18 ± 0.28) × 105 M−1 and K2a = (1.57 ± 0.77) × 105 M−1) with CT-DNA. Isothermal titration calorimetry (ITC) studies revealed that these complexes bind to CT-DNA through an entropically driven process. Both the complexes showed photo-induced cytotoxicity and exhibit apoptotic activity under photo-irradiation conditions. The comet assay indicated that these complexes can damage cellular DNA, which is attributed to the significant build-up of 1O2 level even on irradiation with low intensity light (10 J cm−2, λRange 450–480 nm). This photoinduced DNA damage and apoptosis in A549 cells was induced by reactive oxygen species (ROS) and occurred through up-regulation of apoptotic marker caspase-3. Control experiments under dark conditions revealed an insignificant cytotoxicity towards these cells for two photosensitive molecules. [ABSTRACT FROM AUTHOR]

The proton-coupled electron-transfer (PCET) reaction is investigated for a newly synthesized imidazole-anthraquinone biomimetic model with a photoactive RuII-polypyridyl moiety that is covalently coupled to the imidazole fragment. Intramolecular H-bonding interactions between imidazole and anthraquinone moieties favor the PCET process; this can be correlated to an appreciable positive shift in the one-electron reduction potential of the coordinated anthraquinone moiety functionalized with the imidazole fragment. This can also be attributed to the low luminescence quantum yield of the RuII-polypyridyl complex used. The dynamics of the intramolecular electron-transfer (ET) and PCET processes are studied by using femtosecond transient absorption spectroscopy. The steady-state spectroscopic studies and the results of the time-resolved absorption studies confirm that H-bonded water molecules play a major role in both ET and PCET dynamics as a proton relay in the excited state. The electron-transfer process is followed by a change in the H-bonding equilibrium between AQ and imidazole in acetonitrile solvent, and protonation of AQ.− by water leads to PCET in the presence of water. A slower forward and backward electron-transfer rate is observed in the presence of D2O compared with that in H2O. These results provide further experimental support for a detailed understanding of the PCET process. [ABSTRACT FROM AUTHOR]

A proton-coupled electron transfer (PCET) reaction in a hydrogen-bonded charge-transfer (CT) complex of 4-([2,2′-bipyridin]-4-yl)phenol (bpy-phenol) with a F- ion has been investigated by ultrafast time-resolved transient absorption spectroscopy. The phenolic receptor molecule, bpy-phenol, binds to the F- ion through a hydrogen bond and senses the F- ion via the Stokes-shifted CT band. Upon photoexcitation, CT from the phenol residue to the bpy residue promotes proton transfer from the phenol radical cation (ArOH•+) to the fluoride ion at ultrafast time scales of <150 fs (instrument response function limited) and 3 ps, separately. The fast and slow proton-transfer times are linked to two different types of hydrogen-bonding networks between the phenol residue and fluoride ion. Crystalline water in the fluoride salt hydrates mediates the proton-transfer reaction. This work demonstrates the participation of a hydrogen-bonded water bridge within a PCET reaction in a water-restricted environment. [ABSTRACT FROM AUTHOR]