A simple accurate, sensitive reproducible spectrofluorimetric method was developed for the analysis of citalopram in pure and pharmaceutical dosage form. Citalopram showed strong native fluorescence in 0.05 M sulphuric acid having excitation at 239 nm and emission at 300 nm. All parameters like the effect of different solvents, pH, dilutions, reaction time, temperature and effect of excipients were thoroughly investigated. The calibration graph was linear in the range from 0.100 to 0.900 μg/ml. The proposed method was statistically validated and successfully applied for analysis of tablet dosage forms. The percentage recovery was found to be between 99.08% to 99.28%.

A sensitive and selective high performance liquid chromatographic (HPLC) method was developed and validated for quantification of lacosamide in rat plasma. A liquid-liquid extraction procedure was optimized to extract lacosamide from rat plasma. Chromatographic separation was accomplished using a reversed phase C18 Hichrom (250×4.6 mm, 5 µm) column with the mobile phase consisting of acetonitrile-phosphate buffer (pH 3.2±0.1; 20 mM) (21:79, v/v) at a flow rate of 1 mL/min. Both intra- and inter day assay precision and accuracy were lower than 15% CV. The lower limit of quantitation was 25 ng/mL for lacosamide and the response was linear in a concentration range from 25 to 10 000 ng/mL. The developed method was successfully used for the preclinical pharmacokinetic study of lacosamide in rats.

In this present study a new co-crystals of zoledronic acid with DL-tartaric acid and nicotinamide has been developed with improved solubility. Zoledronic acid is a class III drug with poor oral bioavailability due to its poor permeability and low aqueous solubility; hence an attempt has been made to improve its solubility by co-crystallization technology. Pharmaceutical cocrystals are multi-component crystals with a stoichiometric ratio of active pharmaceutical ingredients (APIs) and cocrystal coformers (CCFs) that are assembled by noncovalent interactions such as hydrogen bonds, π-π packing, and Vander Waals forces. In this study the coformers selected were DL-tartaric acid and nicotinamide based on ease of hydrogen bond formation. The co-crystal of zoledronic acid with DL-tartaric acid were prepared in three ratios (1 : 1, 1 : 2 and 2 : 1) by slow solvent evaporation method and with nicotinamide in 1 : 1 ratio by dry grinding method. The formation of co-crystal was confirmed by powder X-ray diffractometry (PXRD), differential scanning calorimetry (DSC) and Fourier transform (FT)IR. The dynamic solubility of co-crystals with DL-tartaric acid in the ratios 1 : 1, 1 : 2 and 2 : 1 increased by fold as compared to pure drug.

A simple, rapid, and accurate RP-HPLC method was developed for the determination of tolterodine in solid pharmaceutical dosage form. The method showed a linear response for concentration in the range of 1-15µg/ml using acetonitrile:potassium dihydrogen phosphate (50:50,v/v) as the mobile phase with detection at 284 nm and a flow rate of 1ml/min. The method was statistically validated for accuracy, precision, linearity, range, robustness, and stock solution stability. Recovery studies of the dosage form were also carried out and the mean recovery was found to be 98.35±1.01 %. Due to the simplicity, rapidity, and accuracy the method could be used for routine quality control analysis.

A simple, accurate, specific and stability-indicating RP-HPLC method was developed for simultaneous determination of chlorzoxazone, diclofenac sodium and paracetamol, using C18 Vydac Monomeric 120A (250 × 4.6mm, 5μ) at 40ºC. The mobile phase contains a mixture of 20mM potassium dihydrogen phosphate buffer (pH 6.2 adjusted with potassium hydroxide) and acetonitrile (30:70 v/v). The flow rate was 1ml/min and detection was carried out at 275nm using PDA detector. The retention time of paracetamol, chlorzoxazone and diclofenac sodium were 3.28mins, 13.27mins and 15.61mins respectively. The analytical curve was linear over a concentration range of 0.65- 6.5μg/ml for paracetamol, 1-10μg/ml for chlorzoxazone and 0.1-1μg/ml for diclofenac sodium. The drugs in bulk and tablet were subjected to acid and alkali hydrolysis, oxidation, thermal and photolytic degradation. This method can be successfully employed for simultaneous quantitative analysis of Chlorzoxazone, Diclofenac sodium and Paracetamol in bulk drug and tablet formulation.