Emerging technologies for the non-invasive characterization of physical-mechanical properties of tablets

The density, porosity, breaking force, viscoelastic properties, and the presence or absence of any structural defects or irregularities are important physical-mechanical quality attributes of popular solid dosage forms like tablets. The irregularities associated with these attributes may influence the drug product functionality. Thus, an accurate and efficient characterization of these properties is critical for successful development and manufacturing of a robust tablets. These properties are mainly analyzed and monitored with traditional pharmacopeial and non-pharmacopeial methods. Such methods are associated with several challenges such as lack of spatial resolution, efficiency, or sample-sparing attributes. Recent advances in technology, design, instrumentation, and software have led to the emergence of newer techniques for non-invasive characterization of physical-mechanical properties of tablets. These techniques include near infrared spectroscopy, Raman spectroscopy, X-ray microtomography, nuclear magnetic resonance (NMR) imaging, terahertz pulsed imaging, laser-induced breakdown spectroscopy, and various acoustic- and thermal-based techniques. Such state-of-the-art techniques are currently applied at various stages of development and manufacturing of tablets at industrial scale. Each technique has specific advantages or challenges with respect to operational efficiency and cost, compared to traditional analytical methods. Currently, most of these techniques are used as secondary analytical tools to support the traditional methods in characterizing or monitoring tablet quality attributes. Therefore, further development in the instrumentation and software, and studies on the applications are necessary for their adoption in routine analysis and monitoring of tablet physical-mechanical properties

The enhancement of the aqueous solubility of ritonavir via formulation of a drug-phospholipid complex

Objective: To evaluate the enhancement of aqueous solubility of a poorly water soluble drug ritonavir by forming its complex with a phospholipid (Phospholipon®90H)

Sources of resistance to selected chickpea diseases

Chickpea (Cicer arietinum L.) is an important grain legume crop of dryland agriculture in Asia, Africa, and Central and South America..

Effects of Soil Solarization on Pigeonpea and Chickpea. Information Bulletin No.11

The experience gained with field tests on the effects of soil solarization on pigeonpea(Cajanus cajan (L.) Millsp.)and chickpea (Cicer arietinum L.) crops through a multidisciplinary team effort, at ICRISAT Center during 1984-87, is highlighted. The studies were conducted in fields infested wi th fusarium wilt. Solarization was done by covering the soil with transparent polythene sheeting(100μm thick)for 6-8 weeks during summer(Apri l/May). This increased soil temperatures by 6-10°C in the 0-20-cm soil profile. Other changes recorded were increased mineralization of soil nitrogen to nitrate, a decline in populations of fusarium propagules and plant parasitic nematodes, and decreased weed infestation. When the crops were grown, effective control of fusarium wilt disease in the susceptible genotypes of pigeonpea and chickpea was observed along with improved plant growth and yield. Nodulation and N-fixation were adversely affected because of the decline in Rhizobium population with solarization. However, plant growth and yield were not adversely affected probably because of the compensatory effect of increased soil nitrate. Even in wilt-resistant genotypes of both crops, particularly of pigeonpea, there was a significant increase in yield indicating beneficial effects of solarization other than disease control. There was a considerable residual effect of solarization in the second and third seasons on yield of chickpea, but not of pigeonpea. Different techniques and methods employed in applying solarization and in assessing its impact are described. The implications of utilizing solarization for these and other crops are discussed

Management of Soil-Borne Diseases of Grain Legumes Through Broad-Spectrum Actinomycetes Having Plant Growth-Promoting and Biocontrol Traits

Chickpea (Cicer arietinum L.) and pigeonpea (Cajanus cajan L.) are the two important grain legumes grown extensively in the semiarid tropics (SAT) of the world, where soils are poor in nutrients and receive inadequate/erratic rainfall. SAT regions are commonly found in Africa, Australia, and South Asia. Chickpea and pigeonpea suffer from about 38 pathogens that cause soil-borne diseases including wilt, collar rot, dry root rot, damping off, stem canker, and Ascochyta/Phytophthora blight, and of which three of them, wilt, collar rot, and dry root rot, are important in SAT regions. Management of these soil-borne diseases are hard, as no one control measure is completely effective. Advanced/delayed sowing date, solarization of soil, and use of fungicides are some of the control measures usually employed for these diseases but with little success. The use of disease-resistant cultivar is the best efficient and economical control measure, but it is not available for most of the soil-borne diseases. Biocontrol of soil-borne plant pathogens has been managed using antagonistic actinobacteria, bacteria, and fungi. Actinobacterial strains of Streptomyces, Amycolatopsis, Micromonospora, Frankia, and Nocardia were reported to exert effective control on soil-borne pathogens and help the host plants to mobilize and acquire macro- and micronutrients. Such novel actinomycetes with wide range of plant growth-promoting (PGP) and antagonistic traits need to be exploited for sustainable agriculture. This chapter gives a comprehensive analysis of important soil-borne diseases of chickpea and pigeonpea and how broad-spectrum actinomycetes, particularly Streptomyces spp., could be exploited for managing them

Chickpea

The narrow genetic base of cultivated chickpea warrants systematic collection, documentation and evaluation of chickpea germplasm and particularly wild Cicer species for effective and efficient use in chickpea breeding programmes. Limiting factors to crop production, possible solutions and ways to overcome them, importance of wild relatives and barriers to alien gene introgression and strategies to overcome them and traits for base broadening have been discussed. It has been clearly demonstrated that resistance to major biotic and abiotic stresses can be successfully introgressed from the primary gene pool comprising progenitor species. However, many desirable traits including high degree of resistance to multiple stresses that are present in the species belonging to secondary and tertiary gene pools can also be introgressed by using special techniques to overcome pre- and post-fertilization barriers. Besides resistance to various biotic and abiotic stresses, the yield QTLs have also been introgressed from wild Cicer species to cultivated varieties. Status and importance of molecular markers, genome mapping and genomic tools for chickpea improvement are elaborated. Because of major genes for various biotic and abiotic stresses, the transfer of agronomically important traits into elite cultivars has been made easy and practical through marker-assisted selection and marker-assisted backcross. The usefulness of molecular markers such as SSR and SNP for the construction of high-density genetic maps of chickpea and for the identification of genes/QTLs for stress resistance, quality and yield contributing traits has also been discussed

Chickpea and Groundnut Seed-borne Diseases of Economic Importance: Transmission, Detection and Control

With the establishment of International Agricultural Research Centers (IARC) the international exchange of seed has greatly increased. For example, during 1989 ICRISAT exported 13164 samples of chickpea seed and 6095 samples of groundnut seed to 41 and 37 countries, respectively. There is always a risk that pathogens can be transmitted by seed. Seed-borne fungi, bacteria and viruses result in yield losses, reduction in seed germination, increased risk of deterioration in storage, and harmful effects on humans and animals because of toxic metabolites of certain mold fungi