Characterization

INTRODUCTION: Proniosomal gels are generally present in transparent, translucent or white semisolid gel texture, which makes them physically stable during storage and transport. Due to the limited solvent system present, the proniosomes formed were the mixture of many phases of liquid crystal, viz. lamellar, hexagonal and cubic phase liquid crystals as given in dissolution of most surfactants in water, leads to the formation of lipotropic liquid crystals rather than micelle solution. Lamellar phase shows sheets of surfactants arranged in bilayer form, whereas in hexagonal phase cylindrical units are packed in hexagonal fashion. Cubic phase consists of curved bio-continuous lipid bilayer extending in three dimensions, separating two congruent networks of water channels. These liquid crystals present an attractive appearance because of their, transparency and high viscosity, although in the beginning of its formation, a short range of less viscous compositions (so called liquid/gel compositions) appear in some cases. Addition of water leads to interaction between water and polar groups of the surfactant results in swelling of bilayers. When the concentration of solvent is increased above a limited value, the bilayer tends to form random spherical structures, i.e., multilamellar, multivesicular structures. When shaken with water i.e., the aqueous phase of water, complete hydration takes place leading to the formation of niosomes. The beauty of these proniosomes lies in their ability to rearrange as stable niosomal suspensions, on hydration with water.

ABSTRACTNanotechnology is the advancing technology which is based on the study of manipulating the matter on a Nano scale range, and it refers to the constructing and engineering of the functional systems at atomic level. Nanotechnology lead to the development of various types of novel drug delivery systems like liposomes, microparticles, niosomes and proniosomes. Liposomes and niosomes has some demerits like leaking, fusion, aggregation, distribution, transportation and storage. To overcome the demerits of both liposomes and niosomes, proniosomes are developed with enhanced physical stability during storage and transport as they are dry formulation of water soluble carrier encoated with the surfactant and drug encapsulated in the proniosomal vesicles, which helps in prolongation of duration of retention of drug in systemic circulation and by reaching the target tissue shows its action which results in reduced toxicity. This review mainly focusses on demerits of liposomes and niosomes, methods of preparation, characterization and applications of Proniosomes. Keywords: Liposomes, Niosomes, Proniosomes, Stability, Surfactant, Cholesterol, Characterization, Applications.

Calcium oxalate monohydrate (COM) and calcium oxalate dihydrate (COD) are frequently found in urinary calculi (stones). Calcium chelation by citric acid can play a major role in chelation therapy of naphrolithiasis. COM crystals were grown in laboratory using gel growth method, and the inhibitory effect of aqueous citrate on the growth of COM crystals was studied. The results indicate that with an increase in the concentration of citrate, the mass and number of the formed crystals was gradually reduced. The crystals were characterized by Fourier transform infrared spectroscopy (FTIR) to confirm the functional groups and powder X-ray diffraction (XRD) analyses to confirm the phases of the COM and COD crystals. Scanning electron microscopy (SEM) confirmed that the morphology of the crystals changed from elongated hexagonal to tetragonal bipyramidal, which is characteristic of a change from COM to COD. This study confirms that the use of citrate can promote the formation of COD crystals and reduce the nucleation rate of COM crystals, a major component of oxalate urinary stones.