Abhay Raizaday

Development of pH sensitive microparticles of Karaya gum: By response surface methodology.

The objective of the proposed work was to prepare pH sensitive microparticles (MP) of Karaya gum using distilled water as a solvent by spray drying technique. Different formulations were designed, prepared and evaluated by employing response surface methodology and optimal design of experiment technique using Design Expert(®) ver 8.0.1 software. SEM photographs showed that MP were roughly spherical in shape and free from cracks. The particle size and encapsulation efficiency for optimized MP was found to be between 3.89 and 6.5 μm and 81-94% respectively with good flow properties. At the end of the 12th hour the in vitro drug release was found to be 96.9% for the optimized formulation in pH 5.6 phosphate buffer. Low prediction errors were observed for Cmax and AUC0-∞ which demonstrated that the Frusemide IVIVC model was valid. Hence it can be concluded that pH sensitive MP of Karaya gum were effectively prepared by spray drying technique using aqueous solvents and can be used for treating various diseases like chronic hypertension, Ulcerative Colitis and Diverticulitis.

New Therapeutic Approaches in Treating Cancer

After cardiovascular diseases, cancer is the second major cause of mortality in the western world accounting for 24% of all deaths. In European countries each year over three-quarters of a million people die from cancer [1]. Once cancer is diagnosed, a variety of possible treatment options can be considered.The choice of treatment depends on the type of cancer and the extent of its progress.Three basic strategies used in treatment of cancer are: surgery, radio-therapy and chemotherapy. These may be employed either alone or in combination with others [2].

Chapter 12 – Inorganic nanobiomaterials for medical imaging

Nanotechnology involves the creation and use of materials at the level of molecules and atoms, therefore nanotechnology is spreading its annexes to different parts of biomedical applications. The practice of medical imaging has been made possible by advances not only in diagnostic equipment and investigative techniques, but also in the inorganic nanobiomaterials which are being used as various imaging agents that permit visualization of the details of the internal structure using nanotechnology. When inorganic materials are reduced to nanoscale then these nanosized inorganic materials have superior physicochemical properties. For imaging agents it is essential to have rapid clearance from blood so as to obtain low background signals and good images. The surface charge and hydrodynamic diameter of the inorganic nanobiomaterial nanoparticles (NPs) in the presence of plasma proteins are important for their biodistribution, excretion, and rapid clearance from blood. Hence, researchers are now focusing on developing inorganic nanobiomaterial NPs for various medical imaging purposes such as X-ray contrasting agent, magnetic resonance imaging (MRI), positron emission tomography (PET), and ultrasound imaging. Iron oxide particles have been used as a contrasting agent for MRI for 20 years. Quantum dots (QDs) are another category of metal-based NPs which have been used for medical imaging purposes. Nanobiomaterials made from gold and silver have high tunable optical properties which make them suitable for medical imaging purposes. Hence twenty-first century inorganic nanobiomaterials are being extensively investigated for use in medical imaging.

Chapter 9 – Sunscreens

Sunscreens contain active substances which either absorb or scatter radiation. The use of nanotechnology in the formulation of sunscreens helps in improving the aesthetic properties and stability with little or variable influence on effectiveness. The active ingredients in formulations, including titanium dioxide, zinc oxide, octyl methoxy cinnamate, and butyl methoxy dibenzoylmethane have been used extensively to prepare nanoparticle-containing formulations. Over 300 marketed nanoformulations of sunscreens are said to contain physical barriers like titanium dioxide and/or zinc oxide. These physical barriers, when used at proportions to produce strong sun protection, produced a thick white paste which could not be applied easily. Hence these were broken to nano size, which delivered a clear transparent formulation with all desirable properties. Apart from the nanonized use of actives, carrier systems were also used. Solid lipid carriers, nanostructured lipid carriers, liposomes, nanocapsules of actives like octyl methoxy cinnamate, butyl methoxy dibenzoylmethane, and 3,4,5-trimethoxybenzoylchitin have been formulated most commonly to augment the effectiveness and stability. In this chapter a discussion on nanoformulations of sunscreens with special attention to the materials and their carriers would be made along with an insight on merits, demerits, and safety.