Since decade or two, the development of floating drug delivery systems becomes a significant and novel tool as having low density than gastric content. There are various advanced polymers including chitosan, eudragit, etc., and excipients such as; pore forming agent, surfactants, etc. All of them are discussed briefly, and results are concluded from various reputed researches. We have discussed all natural and synthetic systems with their effect on the release and other parameters which are essential for the floating formulation development.

Fast dissolving tablets emerge as one of the popular and widely accepted dosage forms, especially for pediatric patients because of incomplete development of the muscular and nervous system and a case of geriatric patients suffering from Parkinson’s disorder or hand tremors. Few solid dosage forms like capsules and tablets are present days facing the problems like difficulty in swallowing (dysphagia), resulting in many incidences of non-compliance and making the therapy ineffective. Oral dosage form and oral route are the most preferred route of administration for various drugs have limitations like first-pass metabolism, psychiatric patients, bedridden and uncooperative patients. FDTs are disintegrating or dissolve quickly in the saliva without a need of water. Fast dissolving tablets are designed to dissolve in saliva remarkably faster, within a few seconds (less than 60 seconds), and those are real fast-dissolving tablets. FDTs formulations contain super disintegrants to enhance the disintegration rate of a tablet in the buccal cavity. FDTs have advantages such as easy portability and manufacturing, accurate dosing, good chemical and physical stability and an ideal alternative for geriatric and pediatric patients. FDTs have disintegrated quickly, absorb faster so, in vitro drug release time improve and this property of drugs (dosage form) enhanced bioavailability. FDT formulations have the advantage of both conventional tablet formulation and liquid dosage form. There are several technologies that are conventional or patented based on spray drying, cotton candy process, sublimation, melt granulation, direct compression freezes drying/lyophilization, phase transition process, mass extrusion, etc. have been developed for manufacturing of FDTs. In this review contain brief information about FDTs including definition, advantages, needs or requirements of FDTs, salient features of FDTs, limitations, challenges to developing FDT, marketed formulations of fast dissolving tablets, etc.

Dental caries is a major lifestyle concern as dental components affect the face of an individual. The issue of tooth decay occurs in every age group throughout the globe. Researchers are probing incipient implements and techniques to develop filling agents for decayed teeth. Zinc oxide (ZnO) powder is utilized mostly as a filling agent. Nanotechnology enhanced the efficiency of compounds of metal oxides utilized for dental caries. The present study aims to investigate the properties of ZnO nanoparticles (NPs) synthesized chemically (using ZnCl2 and NaOH) as well as biologically (using aqueous leaf extract of Murraya paniculata). The XRD patterns confirm that ZnO NPs have a hexagonal crystalline structure with particle sizes of 47 nm and 55 nm for chemically and biologically synthesized NPs, respectively. The FE-SEM data confirm the nanorod and spherical/cubical shape morphologies for the chemically and biologically synthesized ZnO NPs, respectively. FTIR data show the peaks between 4000 and 450 cm−1 of the functional groups of –OH, C-O, –C-H-, and Zn-O bonds. The UV–Vis absorption study indicates a peak around 370 nm and a hump around 360 nm corresponding to the chemically and biologically synthesized ZnO NPs, respectively. An antibacterial bioassay was performed and compared with commercially available ZnO bulk powder against tooth decaying pathogens, viz., Streptococcus mutans, Staphylococcus aureus, E. coli, and Lactobacillus fermentum, and found that both ZnO NPs had results closer to those of the standard drug (rifampicin). Thus, the synthesized ZnO NPs may be utilized as nano-drugs for the application of tooth decaying filling agents. Even biologically synthesized ZnO NPs may be considered more environmentally friendly and less toxic to human health concerns.

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The design of proposed antenna started with consideration of a CPW fed circular patch having patch radius 9.3 mm. This antenna is designed on glass epoxy FR4 substrate material (relative permittivity ε r = 4.4, substrate height h = 1.59 mm and loss tangent 0.025) having size 30 mm x 20 mm x 1.59 mm. Circular Patch Antenna with Defected Ground for UWB ABSTRACTThe design and performance of coplanar waveguide fed modified circular patch antenna for possible application in ultra wideband communication systems with band rejection for upper wireless local area network band (5.15 GHz -5.85 GHz) is reported. This antenna is designed on glass epoxy FR4 substrate having size 30 mm × 20 mm × 1.59 mm. The coplanar waveguide fed circular patch antenna is modified by introducing L shaped slits in ground plane and U shaped slot in patch and performance analysis of antenna is simulated by applying CST microwave studio simulation software. Different designed antennas were tested with available experimental facilities. The developed end product shows a nice matching with feed network at frequencies 2.62 GHz, 3.94 GHz and 8.50 GHz and provides 10.38 GHz (3.33 GHz -13.71 GHz) impedance bandwidth with wireless local area network 5.5 GHz (4.74 GHz -6.15 GHz) band rejection. The co and cross polar patterns in elevation and azimuth planes at two frequencies namely 2.62 GHz and 3.94 GHz are obtained which dictate that co-polar patterns are significantly better than cross polar patterns. The simulated peak gain of antenna is close to 3.86 dBi and gain variation with frequency shows a sharp gain decrease in the frequency range 4.74 GHz to 6.15 GHz. The length L g and width W g of the ground plane of considered geometry are 8.0 mm and 7.0 mm, respectively. The gap G p between patch and ground is 1.8 mm whereas the gap g between the strip line and ground plane is 0.50 mm as shown in Fig. 1(a). The length f L and width f w of feed line are 10.8 mm and 5.0 mm, respectively. The considered feed line is electrically thick and contributes in the overall performance of antenna. These design parameters are obtained after extensive optimizations. A comparison of S 11 variation of this geometry with the geometry having same radiating element on an infinite and finite ground planes is shown in Fig. 1 This antenna is then modified in two steps to improve its performance. Keywords CPW Feed Circular Patch with Defected Ground PlaneIn the first step of modification, two L-shaped slits are introduced one by one to make ground plane defective as shown in Fig. 2. The slit length in ground a and slit width in ground b are taken 5 mm and 3 mm, respectively. The slit width S w1 is optimised by simulating (S 11 ) parameter of antenna considering four different slit widths as shown in Fig. 2(b). Finally for the present work, slit width equal to 0.3 mm is selected because for this slit width, best performance from antenna is realised which is shown in Fig. 2(c). A comparison between simulated and measured reflection coefficient (S 11 ) as a function of frequency...