Objective: A simple, robust, precise, and selective stability-indicating liquid chromatography (LC) method (reverse-phase high-performance LC) was developed for the estimation of simeprevir through quality by design paradigm. Methods: The chromatographic separation was performed on Water’s 2695(Alliance) equipped with a photodiode array detector at 300 nm. The method was developed on Discovery C18 column (250×4.6, 5 mm) using orthophosphoric acid and acetonitrile (55:45 % v/v) with the flow rate of 1 ml/min at 30°C. The degradation studies of simeprevir were carried out under the stress conditions of hydrolysis (acid, base, and neutral), oxidation, photolytic, and thermal as per the International Conference on Harmonization (ICH) guidelines. The peroxide hydrolysis shows more critical impurities which were well resolved from pure drug with the application of design of experiment and optimized the method. Results: Independent variables (critical analytical attributes) selected for the method optimization were mobile phase ratio, flow rate, and temperature of the column based on the risk assessment. The retention time and resolution were selected as the method response. In response surface method, the central composite design and 23 factorial designs were employed for the optimization of the method. The polynomial equation was derived for the estimation of method response. Conclusion: The method was optimized for better resolution among the drug, and impurity peaks were then validated as per the ICH parameters.

Seed is a fertilized mature ovule, which possesses an embryonic plant. When the dry, mature seeds are subjected to imbibition, they release a wide range of organic substances, which include low molecular weight carbonyl compounds (gases and volatiles) and water-soluble organic substances (enzymes and polysaccharides). The volatile organic compounds (VOCs) are molecules of low molecular weight (300 g mol−1) and high vapour pressure (0.01 kPa at 20°C) and include diverse chemical compounds. The nature and emission kinetics of volatiles produced from seeds vary, depending on the moisture content of the seeds. Orthodox seeds stored at ‘low seed moisture content’ undergo seed deterioration, predominantly due to lipid peroxidation, initiated by autoxidation or enzymatic oxidation of unsaturated or polyunsaturated fatty acids. This peroxidation leads to emission of volatile compounds. The quantity of VOCs emitted is positively correlated with the advancement of seed deterioration. With respect to the seed germination process, exposure of seeds to ‘high moisture conditions’ leads to increased respiration, triggers glycolysis and mobilization of storage reserves, resulting in the emission of volatile metabolic products. The quantity of VOCs emitted on commencement of metabolic activity in germinating seeds depends on (1) vigour status and (2) amount of storage reserves. Since it has been established that there is a significant difference between high and low vigour seeds with respect to quantity and profile of VOCs emitted, there is great potential for utilizing the VOC profile to obtain a quick and reproducible test of vigour status of crop seeds. In order to harness the VOC profile for quick assessment of vigour status of seeds, research has to be taken up to develop standard protocols for fingerprinting of VOCs for the purpose of seed vigour assessment and to fix the standard volatile biomarker(s) specific to crop and vigour status of seeds.

The importance of availability of quality seed of high-yielding varieties in achieving food security has been recognized globally. The chapter presents an overview of the activities and requirements of seed production system globally, with an emphasis on quality, and highlights the linkages between variety development and seed production programmes. The seed development in angiosperm through the process of fertilization has been briefly touched and understanding the processes underlying pollination, fertilization, seed development, and maturation, which are vital for production of quality seed, has been highlighted. System of variety development and release, maintenance of variety purity during seed multiplication, and their importance have been enumerated to benefit those associated with any seed programme. Seed quality parameters including physical and genetic purity, physiological quality, seed vigour, and health, along with factors determining seed quality, have been presented in a holistic manner. Regulatory mechanism for seed quality assurance including steps in seed certification, seed testing and various field and seed standards has been outlined comparing the Indian system with other major international systems working globally. Procedures for seed health testing and application of advanced molecular marker technologies for varietal identity, genetic purity of seed and detection of seed-borne pathogens, which are becoming increasingly relevant in the present seed scenario, have been discussed. Fundamentals of seed processing for quality upgradation, and improvement of seed quality through enhancement technologies, have been explained. The chapter presents an overview of the importance of seed quality, its indicators, regulations, systems of development of varieties and their maintenance and use of modern tools and techniques for assurance and enhancement of seed quality.

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Pigeonpea seeds were primed with CaCl2 (2%), ZnSO4 (100 ppm), KH2PO4 (1%), KCl (1%), MnSO4 (100 ppm) and water. Primed seeds of ZnSO4 showed increased germination (92 %), drymatter production (0.399 mg seedlings-10) and least values for electrical conductivity (0.110 dSm-1), leachate aminoacid (37.82 mg g-1) and lipid peroxidation (0.137 OD). The best priming treatment was taken to field trial. The plant bioregulators viz., GA3 (200 ppm), NAA (200 ppm), miraculan 2.0 ml/l, cytozyme 2.0 ml/l, CCC 200 ppm and diammonium phosphate 2% were sprayed at 65 days and 80 days after sowing. Under field trial seed priming with ZnSO4 (100 ppm) and foliar spray with CCC 200 ppm reduced the plant height (131 cm), produced more number of branches (18), flowers (993), pods (527), highest seed yield (1520 kg/ha) and 100 seed weight (8.77 g) in kharif season.