Application of Quantitative NMR Spectroscopy to the Quality Evaluation of Diclofenac Gargles as Hospital Preparations.

Hospital preparations are frequently prepared in Japanese hospitals when ready-made formulations to meet patients' needs are unavailable. Although the quality of hospital preparations have to be ensured for efficacy and safety, such quality evaluation tends to be insufficient mainly due to lack of manpower and experimental environments in hospitals. In this paper, we investigated the applicability of quantitative (q)NMR spectroscopy to the quality control of diclofenac gargles as examples of hospital preparations, as it has various merits for the quantitative analysis of mixtures in solutions. Diclofenac gargles are composed of diclofenac, tranexamic acid, and lidocaine, and are used for the pain relief of stomatitis induced by cancer chemotherapy. Aliquots of the gargles, which were prepared five times, were mixed with dimethylsulfone as an internal standard, followed by qNMR measurements. Water signal suppression was achieved using a pulse program, water suppression enhanced through T1 effects, because the pulse program was superior to other ones such as presaturation and one-dimensional nuclear Overhauser effect spectroscopy in terms of quantitativeness. Concentrations of the three medicinal ingredients were simultaneously determined based on the signals selected by considering the spectral separation and the quantitativeness. Consequently, the gargles were found to be prepared with constant quality, and were stable at room temperature for at least four weeks. qNMR is considered to be potentially useful for the quality control of various hospital preparations because of minimal sample pretreatments, lack of need of calibration curves, and its comprehensive detection abilities.

Unique supramolecular complex of diclofenac: structural robustness, crystal-to-crystal solvent exchange, and mechanochemical synthesis.

We describe an unexpected, cyclic supramolecular complex that results from self-assembly of the nonsteroidal anti-inflammatory drug, diclofenac and 4,4'-azopyridine. The cycles self-assemble into 1D columns occupied by solvent, which can be removed at elevated temperatures (>100 °C) while retaining crystallinity. The complex exhibits solvent exchange ability that occurs through crystal-to-crystal transformations. Finally, the complex can be synthesized using mechanochemistry. Materials exhibiting the structural framework and robustness described here could be applied to removal of hazardous materials or undesirable solvents.

Diclofenac-Derived Hybrids for Treatment of Actinic Keratosis and Squamous Cell Carcinoma.

In this work, hybrid compounds 1-4 obtained by conjugation of the non-steroidal anti-inflammatory drug diclofenac, with natural molecules endowed with antioxidant and antiproliferative activity were prepared. The antiproliferative activity of these hybrids was evaluated on immortalized human keratinocyte (HaCaT) cells stimulated with epidermal growth factor (EGF), an actinic keratosis (AK) model, and on human squamous cell carcinoma (SCC) cells (A431). Hybrid 1 presented the best activity in both cell models. Self-assembling surfactant nanomicelles have been chosen as the carrier to drive the hybrid 1 into the skin; the in vitro permeation through and penetration into pig ear skin have been evaluated. Among the nanostructured formulations tested, Nano3Hybrid20 showed a higher tendency of the hybrid 1 to be retained in the skin rather than permeating it, with a desirable topical and non-systemic action. On these bases, hybrid 1 may represent an attractive lead scaffold for the development of new treatments for AK and SCC.

Synthesis, crystal structures and characterizations of three new copper(II) complexes including anti-inflammatory diclofenac.

Three new diclofenac-based copper(II) complexes, namely tetrakis{µ-2-[2-(2,6-dichloroanilino)phenyl]acetato-κ2O:O'}bis(methanol-κO)copper(II), [Cu2(µ-dicl)4(CH3OH)2] (1), bis{2-[2-(2,6-dichloroanilino)phenyl]acetato-κ2O,O'}bis(1-vinyl-1H-imidazole-κN3)copper(II), [Cu(dicl)2(vim)2] (2), and bis{2-[2-(2,6-dichloroanilino)phenyl]acetato-κ2O,O'}bis(1H-imidazole-κN3)copper(II), [Cu(dicl)2(im)2] (3) [dicl is diclofenac (C14H10Cl2NO2), vim is 1-vinylimidazole (C5H6N2) and im is imidazole (C3H4N2)], have been synthesized and characterized by elemental analysis, FT-IR spectroscopy, thermal analysis and single-crystal X-ray diffraction. X-ray diffraction analysis shows that complex 1 consists of dimeric units in which the dicl ligand exhibits a bidentate syn,syn-µ2 coordination mode linking two copper(II) centres. Complexes 2 and 3 have mononuclear units with the general formula [Cu(dicl)2L2] (L is vim or im) in which the CuII ions are octahedrally coordinated by two L and two dicl chelating ligands. The L and dicl ligands both occupy the trans positions of the coordination octahedron. The different coordination modes of dicl in the title complexes were revealed by Fourier transform IR (FT-IR) spectroscopy. The spin matching between the copper(II) centres in the dimeric [Cu2(µ-dicl)4(CH3OH)2] units was also confirmed by magnetic data to be lower than the spin-only value and electron paramagnetic resonance (EPR) spectra. The thermal properties of the complexes were investigated by thermogravimetric (TG) and differential thermal analysis (DTA) techniques.

Development and evaluation of immediate release diclofenac sodium suppositories.

The objective of present study was to develop and evaluate polyethylene glycol (PEG) based diclofenac sodium suppositories. This study used water soluble PEG bases (1000, 4000 and 6000) in different combinations to formulate suppositories, which were further subjected for their physicochemical properties evaluation such as weight variation, average melting point, content uniformity and disintegration. Dissolution test was used to perform the in vitro release rate studies of the suppositories. The suppository (P3) containing PEG-6000 (50%) and PEG-4000 (50%) exhibited rapid in vitro release rate of diclofenac sodium. Moreover, homogeneous distribution of diclofenac sodium is found in all six formulations. The in vitro release patterns of diclofenac sodium from the marketed Voltral suppository (100mg) and formulated suppositories were also compared and found in standard limits.

Diclofenac 1,3,4-Oxadiazole Derivatives; Biology-Oriented Drug Synthesis (BIODS) in Search of Better Non-Steroidal, Non-Acid Antiinflammatory Agents.

BACKGROUND: Inflammation is defined as the response of immune system cells to damaged or injured tissues. The major symptoms of inflammation include increased blood flow, cellular influx, edema, elevated cellular metabolism, reactive oxygen species (ROS) nitric oxide (NO) and vasodilation. This normally protective mechanism against harmful agents when this normal mechanism becomes dysregulated that can cause serious illnesses including ulcerative colitis, Crohn's disease, rheumatoid arthritis, osteoarthritis, sepsis, and chronic pulmonary inflammation. METHOD: In this study synthetic transformations on diclofenac were carried out in search of better non-steroidal antiinflammatory drugs (NSAIDs), non-acidic, antiinflammatory agents. For this purpose diclofenac derivatives (2-20) were synthesized from diclofenac (1). All derivatives (2-20) and parent diclofenac (1) were evaluated for their antiinflammatory effect using different parameters including suppression of intracellular reactive oxygen species (ROS), produced by whole blood phagocytes, produced by neutrophils, and inhibition of nitric oxide (NO) production from J774.2 macrophages. The most active compound also evaluated for cytotoxicity activity. RESULTS: Diclofenac (1) inhibited the ROS with an IC50 of 3.9 ± 2.8, 1.2 ± 0.0 µg/mL respectively and inhibited NO with an IC50 of 30.01 ± 0.01 µg/mL. Among its derivatives 4, 5, 11, 16, and 20, showed better antiinflammatory potential. The compound 5 was found to be the most potent inhibitor of intracellular ROS as well as NO with IC50 values of 1.9 ± 0.9, 1.7 ± 0.4 µg/mL respectively and 7.13 ± 1.0 µg/mL, respectively, and showed good inhibitory activity than parent diclofenac. The most active compounds were tested for their toxic effect on NIH-3T3 cells where all compounds were found to be non-toxic compared to the standard cytotoxic drug cyclohexamide. CONCLUSION: Five derivatives were found to be active. Compound 5 was found to be the most potent inhibitor of ROS and NO compared to parent diclofenac 1 and standard drugs ibuprofen and L-NMMA, respectively. The most active compounds 1, 4, 5, 11 and 20 were found to be non-toxic on NIH-3T3 cells. Compound 4, 5, and 20 also showed good antiinflammatory potential, compound 11 and 16 showed moderate and low level of inhibition, respectively.

Application of a Biodegradable Polyesteramide Derived from L-Alanine as Novel Excipient for Controlled Release Matrix Tablets.

This pre-formulation study assays the capacity of the polyesteramide PADAS, poly (L-alanine-dodecanediol-L-alanine-sebacic), as an insoluble tablet excipient matrix for prolonged drug release. The flow properties of PADAS were suitable for tableting, and the compressibility of tablets containing exclusively PADAS was evaluated by ESEM observation of the microstructure. The tablets were resistant to crushing and non-friable and they did not undergo disintegration (typical features of an inert matrix). Tablets containing 33.33% sodium diclofenac (DF), ketoprofen (K) or dexketoprofen trometamol (DK-T) as a model drug, in addition with 66.67% of polymer, were formulated, and the absence of interactions between the components was confirmed by differential scanning calorimetry. Dissolution tests showed that PADAS retained DF and K and prolonged drug release, following a Higuchi kinetic. The tablets containing DK-T did not retain the drug sufficiently for prolonged release to be established. Tablets containing DK-T and 66.67, 83.33 or 91.67% PADAS, compressed at 44.48 or 88.96 kN, were elaborated to determine the influence of the polymer amount and of the compression force on DK-T release. Both parameters significantly delayed drug release, except when the proportion of polymer was 91.67%.

Preparation and Evaluation of Diclofenac Sodium Tablet Coated with Polyelectrolyte Multilayer Film Using Hypromellose Acetate Succinate and Polymethacrylates for pH-Dependent, Modified Release Drug Delivery.

Polyelectrolyte multilayer (PEM) film formed due to the electrostatic interaction between oppositely charged polyelectrolytes is of considerable interest because of their potential applications as both drug carriers and surface-modifying agents. In this study, in vitro studies were carried out on polyelectrolyte complexes formulated with Eudragit E (EE) and hypromellose acetate succinate (HPMCAS). The complexes of EE and HPMCAS were formulated by non-stoichiometric method. The prepared IPCs were investigated using Fourier transform infrared spectroscopy. Diclofenac sodium (DS) tablets were prepared and were coated with polymer solution of HPMCAS and EE to achieve pH-dependent and sustained-release tablets. Tablets were evaluated for their physical characteristics and in vitro drug release. The results of pharmacokinetic studies in rabbits showed that the selected formulation (F6) exhibited a delayed peak plasma concentration and marked sustained-release effect of drug in the in vivo drug release in comparison with marketed tablet. The suitable combination of PEM film based on EE and HPMCAS demonstrated potential candidate for targeted release of DS in the lower part of the gastrointestinal (GI) tract.

Synthesis, hydrolysis kinetics and pharmacological evaluation of aceclofenac prodrugs.

The mutual prodrugs of aceclofenac with various naturally available antioxidants; menthol, thymol, eugenol, guiacol and vanillin have been synthesized by the DCC coupling method, purified and characterized by spectral data, as well as, partition coefficient, solubility and hydrolytic studies. The title compounds have more lipophilic character as compared to the parent moieties and good stability in acidic environment, which is prerequisite for the oral absorption of the drug. Under gastric as well as intestinal pH conditions these prodrugs showed variable susceptibility towards hydrolysis. The synthesized derivatives were evaluated for antiinflammatory, analgesic activities and ulcerogenic potential. Prodrug showed improved solubility in organic solvents, which implies lipophilic character of ester prodrugs and were also found to be chemically stable in acidic environment. The aceclofenac mutual prodrugs showed improved analgesic and anti-inflammatory activities with reduced ulcerogenicity.

Synthesis, spectroscopic and thermal studies of Mg(II), Ca(II), Sr(II) and Ba(II) diclofenac sodium complexes as anti-inflammatory drug and their protective effects on renal functions impairment and oxidative stress.

The main task of our present study is the preparation of newly complexes of Mg(II), Ca(II), Sr(II) and Ba(II) with diclofenac which succeeded to great extent in alleviating the side effects of diclofenac alone and ameliorating the kidney function parameters and antioxidant capacities with respect to diclofenac treated group alone. The Mg(II), Ca(II), Sr(II) and Ba(II) with diclofenac have been synthesized and characterized using infrared, electronic and (1)H NMR spectral, thermogravimetric and conductivity measurements. The diclofenac ligand has been found to act as bidentate chelating agent. Diclofenac complexes coordinate through the oxygen's of the carboxyl group. The molar ratio chelation is 1:2 (M(2+)-dic) with general formula [M(dic)2(H2O)2]⋅nH2O. Antibacterial screening of the alkaline earth metal complexes against Escherichia coli (Gram-ve), Bacillus subtilis (Gram+ve) and anti-fungal (Asperagillus oryzae, Asperagillus niger, Asperagillus flavus) were investigated. The kidney functions in male albino rats were ameliorated upon treatment with metal complexes of dic, which are represented by decreasing the levels of urea and uric acid to be located within normal values. The other looks bright spot in this article is the assessment of antioxidant defense system including SOD, CAT and MDA with the help of Sr(2+), Mg(2+) and Ca(2+)-dic complexes. The hormones related to kidney functions and stresses have been greatly ameliorated in groups treated with dic complexes in comparable with dic treated group.

Zinc-aceclofenac complex: synthesis, hydrolysis study and antiinflammatory studies.

Aceclofenac, a nonsteroidal anti-inflammatory drug, has a propensity to cause gastric ulcers, while zinc ions are known to possess anti-ulcer and anti-inflammatory activities. With a view to reduce the gastroenteropathies associated with aceclofenac, its zinc complex was prepared and characterized using spectroscopy and differential scanning calorimetry. In vitro hydrolysis study showed that zinc complex of aceclofenac is more stable in HCl buffer (pH 1.2) than in phosphate buffer (pH 7.4) indicating the stability of the complex in stomach. In silico testing of the aceclofenac and its complex using PASS (Prediction of activity spectra of substances) software revealed that the complex might possess antiinflammatory activity which was confirmed by carrageenan-induced rat paw edema test. It has been found that antiinflammatory activity of this complex is comparable with that of parent drug along with reduction in ulcer index. Thus, the use of complex is suggested to be more preferable than aceclofenac alone.

Effects of material properties and speed of compression on microbial survival and tensile strength in diclofenac tablet formulations.

A work has been done to study the effects of material properties and compression speed on microbial survival and tensile strength in diclofenac tablet formulations. Tablets were produced from three formulations containing diclofenac and different excipients (DC, DL and DDCP). Two types of machines (Hydraulic hand press and single punch press), which compress the tablets at different speeds, were used. The compression properties of the tablets were analyzed using Heckel and Kawakita equations. A 3-dimensional plot was produced to determine the relationship between the tensile strength, compression speed and percentage survival of Bacillus subtilis in the diclofenac tablets. The mode of consolidation of diclofenac was found to depends on the excipient used in the formulation. DC deformed mainly by plastic flow with the lowest Py and Pk values. DL deformed plastically at the initial stage, followed by fragmentation at the later stage of compression, whereas DDCP deformed mainly by fragmentation with the highest Py and Pk values. The ranking of the percentage survival of B. subtilis in the formulations was DDCP > DL > DC, whereas the ranking of the tensile strength of the tablets was DDCP > DL > DC. Tablets produced on a hydraulic hand press with a lower compression speed had a lower percentage survival of microbial contaminants than those produced on a single punch press, which compressed the tablets at a much higher speed. The mode of consolidation of the materials and the speed at which tablet compression is carried out have effects on both the tensile strength of the tablets and the extent of destruction of microbial contaminants in diclofenac tablet formulations.

Synthesis of stable isotope labelled internal standards for drug-drug interaction (DDI) studies.

The syntheses of stable isotope labelled internal standards of important CYP-isoform selective probes, like testosterone 1, diclofenac 3, midazolam 5, and dextromethorphan 7, as well as their corresponding hydroxylated metabolites 6ß-hydroxytestosterone 2, 4'-hydroxydiclofenac 4, 1'-hydroxymidazolam 6 and dextrorphan 8 are reported. Microwave-enhanced H/D-exchange reactions applying either acid, base, or homogeneous and heterogeneous transition metal catalysis, or combinations thereof proved to be highly efficient for direct deuterium labelling of the above mentioned probes. Compared to conventional stepwise synthetic approaches, the combination of H/D exchange and biotransformation provides the potential for considerable time- and cost savings, in particular for the synthesis of the stable isotope labelled internal standards of 4'-hydroxydiclofenac 4 and 1'-hydroxymidazolam 6.

Formulation development and Optimization of Diclofenac Sodium Extended release Matrix tablets as per USP standards

Aim: To formulate Diclofenac sodium extended release tablets as per the standards given for extended release tablets of Diclofenac sodium in USP. Materials and Methods: The extended release tablets of Diclofenac sodium was prepared by using different concentration of polymers such as hydroxyl propyl methyl cellulose sodium K4M (HPMC K4M) and hydroxyl propyl methyl cellulose sodium K15M (HPMC K15M). The drug polymer interactions were studied by using Fourier transform infrared (FT-IR) spectroscopy. The in vitro drug release and drug release kinetic studies of all the formulations were performed and compared with the marketed product Fenac SR. The optimization done by considering the factors such as drug release limit given as per USP standard, t50% and release exponent (‘n’ value as per Korsmeyer Peppas). Results and Conclusions: The FT-IR spectroscopy studies revealed that there was no interaction between drug and excipients. The drug release observed that it depends on the concentration and nature of the rate controlling polymers used. The ANOVA studies revealed that the formulations show significant effect in drug release. The optimization studies proved that the formulation containing drug, polymer (HPMC K4M) ratio of 1:1.5 (Formulation M3) is the most satisfactory formulation. The stability studies proved that the formulation is stable(AU)

Objetivo: Formular diclofenaco sódico extendido tabletas de liberación como por las normas dadas para las tabletas de liberación prolongada de diclofenaco sódico en USP. Materiales y métodos: las tabletas de liberación prolongada de sodio diclofenaco fue preparado utilizando diferente concentración de polímeros como sódico de celulosa de metilo hidroxilo propilo K4M (HPMC K4M) y sodio de celulosa de hidroxilo propil metil K15M (HPMC K15M). Las interacciones de polímero de drogas se estudiaron utilizando espectroscopia de (FT-IR) infrarroja de transformada de Fourier. La liberación de drogas in vitro y drogas liberación estudios cinéticos de todas las formulaciones fueron realizadas y en comparación con el producto comercializado Sor Fenac La optimización hecha teniendo en cuenta factores tales como límite de liberación de drogas dado por exponente de t50 estándar, % y liberación USP (‘ n ‘ valor como por Korsmeyer Peppas). Resultados y conclusiones: FT-IR la espectroscopia estudios revelaron que no hubo ninguna interacción entre drogas y excipientes. La liberación de drogas señaló que depende de la concentración y naturaleza de la tasa de control de polímeros utilizados. Los ANOVA los estudios revelaron que las formulaciones muestran un efecto significativo en la liberación de drogas. Los estudios de optimización demostraron que la formulación que contiene drogas, proporción de polímero (HPMC K4M) de 1:1.5 (formulación M3) es la formulación más satisfactoria. Los estudios de estabilidad demostraron que la formulación es estable(AU)

Development and characterization of zein-based microcarrier system for sustained delivery of aceclofenac sodium.

Nonsteroidal anti-inflammatory drugs (NSAIDs) induce gastric injury on long-term usage. This study aims at reducing the side effect of NSAIDs by encapsulating in zein, an acid-resistant biopolymer. Aceclofenac-loaded zein microspheres were prepared by emulsification and solvent evaporation method. The stability of zein microspheres at gastric pH retarded the release of the entrapped drug and hence reduces the possibility of gastric injury. However, the in vitro release of aceclofenac was sustained up to 72 h at intestinal pH. Thus, zein microspheres pave the way for the development of safe and sustained delivery system for NSAIDs thereby achieving the desired therapeutic potential with reduced side effects for chronic inflammatory disorders.

[¹¹C]diclofenac sodium: synthesis and PET assessment of transdermal penetration.

The aim of this work was to study the feasibility of using Positron Emission Tomography (PET) imaging as a new tool to detect transdermal penetration of topical drugs in human subjects. The compound used in the study is sodium 2-[(2,6-dichlorophenyl)amino]phenyl]acetate, better known as diclofenac sodium. This molecule belongs to the family of non-steroidal anti-inflammatory drugs and is considered one of the first choices among non-steroidal anti-inflammatory drugs for the treatment of inflammatory diseases; it is widely used and commercially present in a large number of pharmaceutical forms and formulations. (11)C-labeled diclofenac has been synthesized and coformulated, as an internal indicator, with a proprietary preparation based on the use of a sprayer. The radiolabeled preparation was topically administered to healthy volunteers, and PET imaging was used to evaluate transdermal penetration. Results obtained have demonstrated the efficacy of PET and radiolabeled tracers for the evaluation of transdermal penetration of active pharmaceutical ingredients as topical formulations.

Synthesis, characterization, and biological evaluation of novel diclofenac prodrugs.

Diclofenac ester pro drugs (4, 5, 6) were synthesized and evaluated in vitro and in vivo for their potential use for oral delivery, with the aim of obtaining enzymatically labile and less ulceration drugs than the parent drug diclofenac sodium (1a). Prodrugs 4, 5, 6 were found to be potent anti-inflammatory drugs with less ulcerogenic potential than the parent diclofenac sodium. Prodrugs 4, 5, 6 rapidly underwent enzymatic hydrolysis to release the parent drug diclofenac in 30-60 min in rat liver microsomes (RLM) and rat plasma (RP). Prodrugs were found to be more lipophilic when the partition coefficient was measured in 1-octanol and buffer system at pH 7.4 and 3.0. Diclofenac prodrugs 4, 5, 6 were found to be crystalline in nature (analyzed by PXRD). Prodrug 4 was found to be a superior candidate for the treatment of chronic inflammatory diseases.

Identification of quinone imine containing glutathione conjugates of diclofenac in rat bile.

High-resolution accurate MS with an LTQ-Orbitrap was used to identify quinone imine metabolites derived from the 5-hydroxy (5-OH) and 4 prime-hydroxy (4'-OH) glutathione conjugates of diclofenac in rat bile. The initial quinone imine metabolites formed by oxidation of diclofenac have been postulated to be reactive intermediates potentially involved in diclofenac-mediated hepatotoxicity; while these metabolites could be formed using in vitro systems, they have never been detected in vivo. This report describes the identification of secondary quinone imine metabolites derived from 5-OH and 4'-OH diclofenac glutathione conjugates in rat bile. To verify the proposed structures, the diclofenac quinone imine GSH conjugate standards were prepared synthetically and enzymatically. The novel metabolite peaks displayed the identical retention times, accurate mass MS/MS spectra, and the fragmentation patterns as the corresponding authentic standards. The formation of these secondary quinone metabolites occurs only under conditions where bile salt homeostasis was experimentally altered. Standard practice in biliary excretion experiments using bile duct-cannulated rats includes infusion of taurocholic acid and/or other bile acids to replace those lost due to continuous collection of bile; for this experiment, the rats received no replacement bile acid infusion. High-resolution accurate mass spectrometry data and comparison with chemically and enzymatically prepared quinone imines of diclofenac glutathione conjugates support the identification of these metabolites. A mechanism for the formation of these reactive quinone imine containing glutathione conjugates of diclofenac is proposed.

Sulfonamides of 2-[(2,6-dichlorophenyl)amino]phenyl acetoxyacetic acid and their antibacterial studies.

Abstract: Reaction of 2-[(2,6-dichlorophenyl)amino]phenylacetoxyacetyl chloride 2 with various N'-(substituted aryl)-p-aminobenzenesulfonamide derivatives afforded title compounds. All the final compounds were characterized by the IR spectral data and elemental analysis and screened for antibacterial activity against Gram positive and Gram negativebacterial strains.

Synthesis and pharmacological characterization of a novel nitric oxide-releasing diclofenac derivative containing a benzofuroxan moiety.

1-oxy-benzo[1,2,5]oxadiazol-5-ylmethyl [2-(2,6-dichloro-phenylamino)-phenyl]-acetate, a new diclofenac derivative bearing a benzofuroxan heterocyclic moiety in its structure, was prepared by the reaction of sodium diclofenac and 5-bromomethyl-benzo[1,2,5]oxadiazole 1-oxide. Pharmacological characterization of this modified diclofenac maintained the anti-inflammatory activity similar to its parent compound assayed in vitro and in vivo. The ulcerogenic properties of native diclofenac were not observed with this modified compound, despite the inhibition of prostaglandin E2 gastric content. The better gastric tolerability seems to be related to nitric oxide release ability.