Authors:Janhavi Rao, Mohan Kumar, L. Sathiyanarayanan, Savita Yadav and V. Yadav
A sensitive, selective, precise and stability-indicating high-performance thin-layer chromatographic (HPTLC) method for analysis of sertraline hydrochloride in the bulk drug and in formulations has been established and validated. Aluminum foil HPTLC plates precoated with silica gel 60F254 as stationary phase were used with toluene-ethyl acetate-ethanol-ammonia 8:2:0.5:0.1 (ν/ν). A compact spot was obtained for sertraline hydrochloride (RF 0.33 ± 0.02). Densitometric analysis was performed in absorbance mode at 273 nm. Regression analysis of calibration data revealed a good linear relationship (r2 = 0.9996 ± 0.02) between response and concentration over the range 2000–12000 ng per band. The method was validated for accuracy, precision, linearity, limits of detection and quantification, and robustness. Sertraline hydrochloride was subjected to acidic and alkaline hydrolysis, oxidation, dry heat treatment, and photodegradation. Peaks of degradation products were well resolved from that of the pure drug and had significantly different RF values. Statistical analysis showed the method enabled repeatable and selective analysis of sertraline hydrochloride. The method can be used for routine quantitative analysis of sertraline hydrochloride in the bulk drug and in formulations.
Authors:A. Kamalakannan, L. Mohan, K. Kavitha, S. Harish, R. Radjacommare, S. Nakkeeran, V. K. Parthiban, R. Karuppiah and T. Angayarkanni
Five isolates of Trichoderma viride, Pseudomonas fluorescens and four isolates of Bacillus subtilis were evaluated for their ability to control Rhizoctonia solani, the causal agent of stem and stolon rot of peppermint (Mentha piperita Lin.). Of the various isolates of T. viride, P. fluorescens and B. subtilis tested, TVUV10, PFMMP and BSG3 showed the maximum inhibition of mycelial growth of R. solani. Among these isolates, P. fluorescens, PFMMP recorded the highest inhibition zone against R. solani in vitro and was very effective in reducing disease incidence in greenhouse condition. The effective isolates were evaluated for their ability to induce defense related enzymes and chemicals in plants. Increased activity of phenylalanine ammonia lyase (PAL), peroxidase (PO), polyphenoloxidase (PPO) and total phenolics were recorded in the biocontrol agents pretreated peppermint plants challenged with R. solani. P. fluorescens isolate PFMMP recorded early and increased synthesis of all defense related enzymes and total phenol. Thus, the present study shows that application of biocontrol agents; induce defense related enzymes involved in phenyl propanoid pathway in addition to direct antagonism which collectively contribute for enhanced resistance against invasion of R. solani in M. piperita.