INTRODUCTIONThis study examined the solubility enhancement of 4 cox-2 inhibitors, celecoxib, rofecoxib, meloxicam, and nimesulide, using a series of pure solvents and solvent mixtures. Water, alcohols, glycols, glycerol, and polyethylene glycol 400 (PEG 400) were used as solvents and water-ethanol, glycerol-ethanol, and polyethylene glycol-ethanol were used as mixed-solvent systems. A pH-solubility profile of drugs was obtained in the pH range 7.0 to 10.9 using 0.05M glycine-sodium hydroxide buffer solutions. Lower alcohols, higher glycols, and PEG 400 were found to be good solvents for these drugs. The aqueous solubility of celecoxib, rofecoxib, and nimesulide could be enhanced significantly by using ethanol as the second solvent. Among the mixedsolvent systems, PEG 400-ethanol system had highest solubilization potential. In the case of meloxicam and nimesulide, solubility increased significantly with increase in pH value. Physico-chemical properties of the solvent such as polarity, intermolecular interactions, and the ability of the solvent to form a hydrogen bond with the drug molecules were found to be the major factors involved in the dissolution of drugs by pure solvents. The greater the difference in the polarity of the 2 solvents in a given mixed solvent, the greater was the solubilization power. However, in a given mixedsolvent system, the solubilization power could not be related to the polarity of the drugs. Significance of the solubility data in relation to the development of formulations has also been discussed in this study.Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most widely prescribed medications in the world. As a therapeutic class, NSAIDs exhibit analgesic, antiinflammatory, antipyretic, and platelet inhibitory properties. 1,2 However, these drugs have serious side effects such as gastrointestinal (GI) toxicities, gastric mucosal ulcerations and hemorrhage due to inhibition of prostaglandin production.3,4 The mechanism of action of NSAIDs has been attributed to their ability to inhibit the cyclooxygenase enzyme (cox). Out of the 2 isoforms of cyclooxygenase, cox-1 is responsible for mediating the production of prostaglandin while cox-2 is primarily associated with inflammation, pain, and fever. 5,6 The traditional NSAIDs are nonselective cox inhibitors. Cox-2 selective NSAIDs are, therefore, ideal anti-inflammatory drugs with minimum drug-related side effects, since they spare cox-1 activity.The very poor aqueous solubility and wettability of cox-2 inhibitors, however, give rise to difficulties in the design of pharmaceutical formulations and lead to variable oral bioavailability. The use of cosolvents has been employed by a number of workers [7][8][9] to enhance the solubility of poorly soluble drugs. Some attempts have been made to increase the solubility of nimesulide and meloxicam 10-13 by using techniques other than the use of cosolvents. Enhancement of solubility of celecoxib and rofecoxib has not received much attention so far. In the present study, an attempt has b...

The oral microbiome is diverse in its composition due to continuous contact of oral cavity with the external environment. Temperatures, diet, pH, feeding habits are important factors that contribute in the establishment of oral microbiome. Both culture dependent and culture independent approaches have been employed in the analysis of oral microbiome. Gene-based methods like PCR amplification techniques, random amplicon cloning, PCR-RELP, T-RELP, DGGE and DNA microarray analysis have been applied to increase oral microbiome related knowledge. Studies revealed that microbes from the phyla Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria, Fusobacteria, Neisseria , TM7 predominately inhabits the oral cavity. Culture-independent molecular techniques revealed the presence of genera Megasphaera , Parvimonas and Desulfobulbus in periodontal disease. Bacteria, fungi and protozoa colonize themselves on various surfaces in oral cavity. Microbial biofilms are formed on the buccal mucosa, dorsum of the tongue, tooth surfaces and gingival sulcus. Various studies demonstrate relationship between unbalanced microflora and development of diseases like tooth caries, periodontal diseases, type 2 diabetes, circulatory system related diseases etc. Transcriptome-based remodelling of microbial metabolism in health and disease associated states has been well reported. Human diets and habitat can trigger virus activation and influence phage members of oral microbiome. As it is said, “Mouth, is the gateway to the total body wellness, thus oral microbiome influences overall health of an individual”.

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Bacterial and archaeal diversity in geothermal spring water were investigated using 16S rRNA gene amplicon metagenomic sequencing. This revealed the dominance of Firmicutes, Aquificae, and the Deinococcus-Thermus group in this thermophilic environment. A number of sequences remained taxonomically unresolved, indicating the presence of potentially novel microbes in this unique habitat.

Competitive binding of six COX-2 inhibitors (celecoxib, valdecoxib, etoricoxib, parecoxib sodium, meloxicam and nimesulide) in the presence of three categories of drugs: an antidiabetic (gliclazide), antipsychotic (chlorpromazine) and antibiotic (ceftriaxone sodium) were studied by fluorescence spectroscopy. Data are expressed in terms of the percentage of drug bound in the absence and presence of competing drug and change in the percentage of free drug due to competitive binding. The results are discussed in terms of three cases: decrease in the binding of the parent drug; increase in binding; and no effect by the presence of the competing drug. The relative binding affinity of the parent drug and the displacing compound for human serum albumin (HSA) is not the only factor involved in the competitive mechanism. Binding behaviour of individual drugs was analysed, and explanations for different cases based on the competitive displacement, non-competitive interference, conformational changes in the HSA molecule, and independent binding are presented.