Current Approaches on Gastroretentive Drug Delivery systems

Over recent years, there have been many efforts to develop the absorption rate of medications and the therapeutic efficacy of oral dosage types. GRDDS for strengthen the pharmacological effects of drugs with a small uptake site, are unbalanced at pH greater than 7, are dissolved under acidic region, and are effective local region in the stomach. The gastro retentive systems that have the different evaluation parameter that according to the dosage forms. There are many criteria for the choosing of the drug used in the gastro-retardant systems as the drug should be sparingly stable, it should be compatible with the gastric region, and narrow absorption. In this review, we have summarized the information related to the various approaches for enhancing and prolonging of the dosage forms in the stomach for their extended-release of action. Also talking about the many natural and synthetic polymers is used in the formulation with their different grade and their ratio that affects on the release action. The many scientist and inventors have increased their interest in developing the novel dosage forms and they staying in the stomach for showing the prolonged period action. We have also discussed the novel technology are involved in the gastric retention many companies has been developed the polymer grades for using it in the formulation for showing the retention action. Keywords: Introduction, Approaches, Novel technologies, Polymer used in floating systems

Floating Drug Delivery System: A comprehensive review

The recent literature with some special interest on the principal mechanism of floatation to obtain gastric retention is the main purpose of writing this review on floating drug delivery systems (FDDS). The recent developments in floating drug delivery systems are containing the physiological and formulation variables impacting on gastric retention time, approaches to formulating of single-unit and multiple-unit floating systems, and their classification and formulation aspects are discussed in detail. This review also summarizes evaluation parameters and application of floating drug delivery systems. These systems are useful to several problems introduced during the formulations of a pharmaceutical dosage form. Keywords: floating drug delivery system, gastro-retention, floating beads, gastric technology

Recent advances in micro-electro-mechanical devices for controlled drug release applications

In recent years, controlled release of drugs has posed numerous challenges with the aim of optimizing parameters such as the release of the suitable quantity of drugs in the right site at the right time with the least invasiveness and the greatest possible automation. Some of the factors that challenge conventional drug release include long-term treatments, narrow therapeutic windows, complex dosing schedules, combined therapies, individual dosing regimens, and labile active substance administration. In this sense, the emergence of micro-devices that combine mechanical and electrical components, so called micro-electro-mechanical systems (MEMS) can offer solutions to these drawbacks. These devices can be fabricated using biocompatible materials, with great uniformity and reproducibility, similar to integrated circuits. They can be aseptically manufactured and hermetically sealed, while having mobile components that enable physical or analytical functions together with electrical components. In this review we present recent advances in the generation of MEMS drug delivery devices, in which various micro and nanometric structures such as contacts, connections, channels, reservoirs, pumps, valves, needles, and/or membranes can be included in their design and manufacture. Implantable single and multiple reservoir-based and transdermal-based MEMS devices are discussed in terms of fundamental mechanisms, fabrication, performance, and drug release applications.Fil: Villarruel Mendoza, Luis A.. Comisión Nacional de Energía Atómica. Gerencia de Área de Investigación y Aplicaciones no Nucleares. Gerencia de Desarrollo Tecnológico y Proyectos Especiales. Departamento de Micro y Nanotecnología; ArgentinaFil: Scilletta, Natalia Antonela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia de Área de Investigación y Aplicaciones no Nucleares. Gerencia de Desarrollo Tecnológico y Proyectos Especiales. Departamento de Micro y Nanotecnología; ArgentinaFil: Bellino, Martin Gonzalo. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Constituyentes | Comision Nacional de Energia Atomica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Constituyentes.; ArgentinaFil: Desimone, Martín Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; ArgentinaFil: Catalano, Paolo Nicolás. Comisión Nacional de Energía Atómica. Gerencia de Área de Investigación y Aplicaciones no Nucleares. Gerencia de Desarrollo Tecnológico y Proyectos Especiales. Departamento de Micro y Nanotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentin

NANOPARTICLE INSULIN DRUG DELIVERY-APPLICATIONS AND NEW ASPECTS

Diabetes mellitus is a chronic metabolic disorder caused via the deficiency of pancreatic hormone insulin (Type1 diabetes mellitus) or due to the resistance of cells to insulin secreted by using the body (Type 2 diabetes mellitus). It is a rapidly growing serious situation that inspires a lot of global concern. Exogenous insulin administration is many times used therapy for Type 1 Diabetes Mellitus and gestational diabetes. The traditional subcutaneous insulin injections cause a lot of suffering to the affected person, exceptionally due to pain and secondarily due to dose sensitivity and in additional complications. Hence alternate delivery systems are an area of recreation for medical professionals and a convenient alternative system will be a boon to the patients. As an end result of the technological advances, various invasive and non-invasive delivery systems have been brought in the previous years. Nanotechnology, particle-mediated delivery, pulmonary delivery, buccal spray, etc. are the most current advances

Thermally driven Knudsen gas pump enhanced with a thermoelectric material.

The thesis focuses on improving the flowrate of the Knudsen gas pump. The Knudsen pump uses thermal transpiration as the driving mechanism to pump gas. It is a motionless gas pump as the pump does not require any moving actuators for pumping. The thermally driven gas flow is accomplished in the molecular or transitional gas flow regime. The advantage of this pump is that without any moving parts it avoids friction losses and stiction problems which devices in micro scale are prone to suffering due to scaling issues. Thus, this pump is highly robust and reliable. Knudsen pumps in the past have suffered from the drawback of low flowrates and inability to operate at atmospheric pressure. In the early days lack of micromachining technologies limited minimum channel size which had to be operated at lower than atmospheric pressure to achieve free molecular flow. Various designs have been implemented with an impetus on increasing the flowrate of the pump. The key to this pump is establishing a temperature difference along the length of the channel. A higher temperature difference over a shorter channel length makes the pump more efficient. Pump channels have been made out of various materials like silicon, glass and polymer. The silicon microfabricated single channel conventional design pump suffered from the high thermal conductivity of silicon, which limited the thermal gradient that could be achieved. Silicon was replaced by glass, which has a lower thermal conductivity. The glass micro fluidic pump could pump water in reservoirs but at a slow rate. Renewable forms of Knudsen pump were also made by using nanoporous silica colloidal crystals which are robust and could use solar energy and body heat to create a temperature difference and achieve pumping. The pump powered by body heat produced a maximum pressure differential of 1.5 kPa. However, the use of these pumps is restricted to certain applications due to slow pumping. The polymer material, made of mixed cellulose ester, has a very low thermal conductivity, which aids in maintaining a higher temperature difference between the ends of a channel to achieve a higher flowrate. The polymer material used is in the form of a nanoporous template which has numerous pores each of which acts as a pump and thus the pump\u27s conductance to gas flow is also increased which makes it faster. The pore sizes range from 25 nm to 1200 nm. It has been proven that a smaller channel diameter pump is more efficient. Efficiency decreases as the channel size approaches viscous flow regime. The initial design used a resistive heater to actively heat one end of the channel and a heat sink was used to passively cool the other end of the channel. This design was ineffective in achieving a significant temperature difference for a decent flowrate with the materials like silicon and glass. The conventional Knudsen pump design using a porous polymer matrix as channel material attained a normalized maximum no load flowrate of 135 µL/min-cm2 at 3.81 Watts of input power. This number is low compared to other micropumps. This led to the use of a thermoelectric material, which could actively heat and cool the pump channel ends and provide a much higher temperature difference over the same channel length as compared to the conventional Knudsen pumps which used only active heating of the channel\u27s hot side. The thermoelectric strategy also eliminates the need for a heat sink in the pump. This transforms the design to bi-directional modes of operation. The first design using thermoelectrics is a lateral design in which the pump channels closer to the thermoelectric element developed a higher temperature difference across them compared to the channels away from the thermoelectric element. Thus, the thermoelectric energy was underutilized. Changing to the radial design made the pump more efficient compared to the lateral design since the thermoelectric energy was uniformly distributed on all the pump channels. The radial design also reduced air gap resistances and minimized energy losses which enhanced the output for the same input power. At an input power of 4.18 Watts it achieved a normalized no load flowrate of 408 µL/min-cm2. It also recorded a maximum normalized flowrate of 1.5 mL/min-cm2 while moving a drop of water which to date is the maximum flowrate reported by any Knudsen pump. A theoretical model has been developed to compute the pump\u27s efficiency based on the flowrate and pressure difference obtained by the pump. The efficiency of the radial design pump with the thermoelectric is higher when compared to a conventional pump using a resistive heater whose channels are also made from the same material as that of the thermoelectric pump

Swallowable Wireless Capsule Endoscopy: Progress and Technical Challenges

Wireless capsule endoscopy (WCE) offers a feasible noninvasive way to detect the whole gastrointestinal (GI) tract and revolutionizes the diagnosis technology. However, compared with wired endoscopies, the limited working time, the low frame rate, and the low image resolution limit the wider application. The progress of this new technology is reviewed in this paper, and the evolution tendencies are analyzed to be high image resolution, high frame rate, and long working time. Unfortunately, the power supply of capsule endoscope (CE) is the bottleneck. Wireless power transmission (WPT) is the promising solution to this problem, but is also the technical challenge. Active CE is another tendency and will be the next geneion of the WCE. Nevertheless, it will not come true shortly, unless the practical locomotion mechanism of the active CE in GI tract is achieved. The locomotion mechanism is the other technical challenge, besides the challenge of WPT. The progress about the WPT and the active capsule technology is reviewed

Cochlear Compartments Segmentation and Pharmacokinetics using Micro Computed Tomography Images

Local drug delivery to the inner ear via micropump implants has the potential to be much more effective than oral drug delivery for treating patients with sensorineural hearing loss and to protect hearing from ototoxic insult due to noise exposure. Delivering appropriate concentrations of drugs to the necessary cochlear compartments is of paramount importance; however, directly measuring local drug concentrations over time throughout the cochlea is not possible. Indirect measurement using otoacoustic emissions and auditory brainstem response are ineffective as they only provide an estimate of concentration and are susceptible to non-linear sensitivity effects. Imaging modalities such as MRI with infused gadolinium contrast agent are limited due to the high spatial resolution requirement for pharmacokinetic analysis, especially in mice with cochlear length in the micron scale. We develop an intracochlear pharmacokinetic model using micro-computed tomography imaging of the cochlea during in vivo infusion of a contrast agent at the basal end of scala tympani through a cochleostomy. This approach requires accurately segmenting the main cochlear compartments: scala tympani (ST), scala media (SM) and scala vestibuli (SV). Each scan was segmented using 1) atlas-based deformable registration, and 2) V-Net, a encoder-decoder style convolutional neural network. The segmentation of these cochlear regions enable concentrations to be extracted along the length of each scala. These spatio-temporal concentration profiles are used to learn a concentration dependent diffusion coefficient, and transport parameters between the major scalae and to clearance. The pharmacokinetic model results are comparable to the current state of the art model, and can simulate concentrations for cases involving different infusion molecules and drug delivery protocols. While our model shows promising results, to extend the approach to larger animals and to generate accurate further experimental data, computational constraints, and time requirements of previous segmentation methods need to be mitigated. To this end, we extended the V-Net architecture with inclusion of spatial attention. Moreover, to enable segmentation in hardware restricted environments, we designed a 3D segmentation network using Capsule Networks that can provide improved segmentation performance along with 90% reduction in trainable parameters. Finally, to demonstrate the effectiveness of these networks, we test them on multiple public datasets. They are also tested on the cochlea dataset and pharmacokinetic model simulations will be validated against existing results