Stability.

A new simple, accurate, precise and selective stability-indicating high performance thin layer chromatographic (HPTLC) method has been developed and validated for the determination of Dapoxetine hydrochloride in bulk and in formulation. Chromatographic separation was performed on aluminum plate precoated with Silica Gel 60 F254 using Ethyl Acetate: Methanol (9:1 v/v) as the mobile phase with saturation time 20 min, followed by densitometric scanning at 239 nm. This system was found to give compact spot for Dapoxetine hydrochloride (Rf value 0.78 ± 0.005) and specificity in accordance with international conference on harmonization (ICH) prescribed stress conditions. The calibration curve was found to be linear between 100-700 ng/band. The proposed method was found to be accurate, precise, reproducible, specific and sensitive and applicable for the determination of Dapoxetine in bulk and in formulation. The drug was subjected to stress condition of hydrolysis (acid, base and neutral), oxidation, photolysis and thermal degradation.

There are various techniques to control the release rate of the drugs, among which controlling dissolution rate is most popular due to its success and low cost. The use of sustained release dosage forms is increasing in treatment of acute and chronic diseases as they maintain the concentration of drug in plasma above minimum effective concentration and below the minimum toxic level for extended period of time. Thus, sustained drug delivery results in optimum drug therapy with reduced frequency of dosing and side effects. The objectives of the present investigation were to prepare granules of aceclofenac with different polymers and polymer blends by solid dispersion technique and investigate the different tablet evaluation parameters. Solid dispersions were prepared by solvent evaporation technique by using different polymers (Hydroxypropyl methyl cellulose - K4M, Ethyl cellulose, and Eudragit RS-100).Solid state and drug polymer interactions were studied by Fourier transform infra red spectroscopy, Differential scanning calorimetry, X-ray powder diffraction. The pharmaceutical performance was studied by in-vitro dissolution experiments.  Studies for the kinetics of the drug release from tablets showed a good fit to zero order kinetics indicating better controlled release of the drug. Significant effect was observed with polymer, concentration of polymer mixture on similarity factor. In stability study there was no significant change in the tablet properties after exposure to 40 ± 2 0C and 75 ± 5% RH for a period of 3 months.