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Gums are widely used natural excipients for conventional and novel dosage forms. With the increasing interest in polymers of natural origin, the pharmaceutical world has compliance to use most of them in the formulations. In recent years, there has been a tremendous development in natural products, which are needed to be used for a variety of purposes. Nature has provided us a wide variety of materials to help improves and sustains the health of all living things either directly or indirectly. These natural materials have advantages over synthetic ones since they are chemically inert, nontoxic, less expensive, biodegradable and widely available. They can also be modified in different ways to obtain tailor made materials for drug-delivery systems and thus can compete with the available synthetic excipients. Moreover, the tremendous orientation of Pharma world towards these naturally derived polymers has become a subject of increasing interest to discover, extract and purify such compounds from the natural origin. Gums are the potent candidates to be used in various pharmaceutical formulations as a potential candidate for novel drug delivery system (NDDS). In this review, we describe the developments in natural gums for use in the pharmaceutical sciences.

Pulsed sieved plate columns (PSPCs) are used for liquid–liquid extraction processes in several industries such as mineral processing, pharmaceuticals, and nuclear fuel cycle. Despite their widespread use in the industry, there is a dearth of experimental insights into the local hydrodynamics in PSPC. This work for the first time reports the local hydrodynamics inside a PSPC using the radioactive particle tracking technique. Local instantaneous velocity, mean velocity, turbulent quantities such as root-mean square (rms) velocity, turbulent kinetic energy, and turbulent intensity are measured through the radioactive particle tracking technique. The effects of pulsing velocity and liquid flow rate on local hydrodynamics and turbulence parameters are studied for no net flow and single-phase flow conditions. Results indicate that the mean flow velocity is low; however, significant fluctuating velocity components are generated due to the pulsing action. Though the fluctuations in the axial direction dominate, significant radial velocity is observed in all of the cases. Further, results show that the fluctuations in the axial direction attenuate in the case of single-phase flow when compared with the no flow condition. This leads to lower axial rms velocity, turbulent kinetic energy, and turbulent intensity in the case of single-phase flow as compared with the no flow condition. In all of the cases, significant fluctuations are observed, which signify a higher degree of mixing and hence enhanced mass transfer in PSPCs.

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