PRE-FORMULATION PROFILING OF ACECLOFENAC AND DEVELOPMENT OF A SENSITIVE ANALYTICAL TECHNIQUE FOR ITS ASSESSMENT

Pre-formulation studies are an integral part of formulation development. For the successful development of the formulation, it is essential to perform all the pre-formulation studies. The present work was aimed at systematically investigating the physicochemical properties of aceclofenac, a non-steroidal anti- infl ammatory drug used for the management of rheumatoid arthritis, osteo arthritis and ankylosing spondylitis. The studies included pre-formulation profi ling of the drug in order to fi nalize the excipients for the development of its delivery. Drug characterization was carried out for solubility in different solvent systems, pKa determination, bulk characterization, melting point, dissolution. Further, and some other parameters RP-HPLC method for estimation of the drug was developed and validated. Earlier methods were developed using C18 column for the estimation of drug content. In the present research, an attempt was made to develop and validate an analytical method using HILIC column. The pre-formulation profi ling of the drug was successfully done and a sensitive analytical method was also developed.

Single Isomer N-Heterocyclic Cyclodextrin Derivatives as Chiral Selectors in Capillary Electrophoresis

In order to better understand the chiral recognition mechanisms of positively charged cyclodextrin (CD) derivatives, the synthesis, the pKa determination by 1H nuclear magnetic resonance (NMR)-pH titration and a comparative chiral capillary electrophoretic (CE) study were performed with two series of mono-substituted cationic single isomer CDs. The first series of selectors were mono-(6-N-pyrrolidine-6-deoxy)-β-CD (PYR-β-CD), mono-(6-N-piperidine-6-deoxy)-β-CD (PIP-β-CD), mono-(6-N-morpholine-6-deoxy)-β-CD (MO-β-CD) and mono-(6-N-piperazine-6-deoxy)-β-CD (PIPA-β-CD), carrying a pH-adjustable moiety at the narrower rim of the cavity, while the second set represented by their quaternarized, permanently cationic counterparts: mono-(6-N-(N-methyl-pyrrolidine)-6-deoxy)-β-CD (MePYR-β-CD), mono-(6-N-(N-methyl-piperidine)-6-deoxy)-β-CD (MePIP-β-CD), mono-(6-N-(N-methyl-morpholine)-6-deoxy)-β-CD (MeMO-β-CD) and mono-(6-N-(4,4-N,N-dimethyl-piperazine)-β-CD (diMePIPA-β-CD). Based on pH-dependent and selector concentration-dependent comparative studies of these single isomer N-heterocyclic CDs presented herein, it can be concluded that all CDs could successfully be applied as chiral selectors for the enantiodiscrimination of several negatively charged and zwitterionic model racemates. The substituent-dependent enantiomer migration order reversal of dansylated-valine using PIP-β-CD contrary to PYP-β-CD, MO-β-CD and PIPA-β-CD was also studied by 1H- and 2D ROESY NMR experiments.

pKa Determination of Carvedilol by Spectrophotometry

Proper knowledge of the pKa value of a compound is of uttermost importance for understanding the behavior of a drug inside the body. The pKa value of Nonselective alpha-1 and beta-blocker Carvedilol shows controversies in literature, whereas values between 7.7 and 8.7 have been previously reported. In this research paper, the pKa value of Carvedilol was re-evaluated using UV-vis spectroscopy. The analytical wavelength used was 241nm. The obtained sigmoid pattern was non-linear fitted using the Boltzmann sigmoidal algorithm. The determined pKa was 7.77 ± 0.09. This value is in accordance with some of the literature publications. Since extensive statistics and multiple replicate experiments were performed, it is assumed that 7.8 is the true pKa value of Carvedilol.

Potentiometric pKa determination of biological active phenothiazine in different aqua-organic solvents

Potentiometric titrations of phenothiazines derivatives were performed in methanolwater, ethanol-water, acetonitrile-water and dioxane-water mixtures with varying contents of organic solvent. All titrations were performed in aqua-organic medium at constant ionic strength (0.15 mol⋅dm−3) and at different temperatures (25 to 45 °C). The pKa were determined at different aqua-organic proportions. Effect of temperature and dielectric constant on dissociation constant has been compared. The pKa values were then obtained by Yasuda‐Shedlovsky extrapolation.

PHYSICOCHEMICAL PROPERTIES DETERMINATION OF PICROSIDE-II

The aim of the present study is to determine the physicochemical properties of Picroside-II, a phytochemical obtained from the herb of Picrorhiza kurroa. The solubility study of picroside-II shows that it has better solubility in water up to 2.46 mg/mL than organic solvents. The solubility of picroside-II in linseed oil was found to be 71.46 mg/mL. The solubility of Picroside-II in surfactant like Transcutol P and labrasol was found to be 907.80 and 535.90 mg/mL, respectively. Picroside-II had a melting point in the range of 130 to 135°C. The log P value of picroside-II was estimated using shake flask method followed by UV analysis. The log P value of picroside-II was found to be -0.09675, which shows its hydrophilicity. The pKa determination of picroside-II was carried out by using UV-visible spectrophotometer and the pKa value was found to be 7.80. The particle size distribution of picroside-II powder was also carried out and the maximum particles of picroside-II are in the range of 53-75 μm. Flow properties of picroside-II were also studied. bulk and tapped density of picroside-II powder was found to be 0.149 and 0.248, respectively. The Hausner ratio and compressibility index were also calculated and it was found to be 1.66 and 39.99, which confirm the poor flow properities of picroside-II powder. The angle of repose of picroside-II was found to be 41.08°, which shows the passable flow of picroside-II. Water was found to be the better extractive solvent for picroside-II; the extractive value of picroside-II in water was found to be 9.12%.