Augmenting Photoinduced Charge Transport in a Single-Component Gel System: Controlled In Situ Gel-Crystal Transformation at Room Temperature

2018 ◽  
Vol 24 (23) ◽  
pp. 6217-6230 ◽  
Author(s):  
Sitakanta Satapathy ◽  
Palani Prabakaran ◽  
Edamana Prasad
Keyword(s):  
Charge Transport ◽  
Room Temperature ◽  
Single Component ◽  
In Situ Gel ◽  
Crystal Transformation ◽  
Photoinduced Charge ◽  
Gel System

Sustained Ocular Drug Delivery from a Temperature and pH Triggered Novel In Situ Gel System

Drug Delivery ◽  
2007 ◽  
Vol 14 (8) ◽  
pp. 507-515 ◽  
Author(s):  
Himanshu Gupta ◽  
Sanyog Jain ◽  
Rashi Mathur ◽  
Pushpa Mishra ◽  
Anil K. Mishra ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Ocular Drug Delivery ◽  
In Situ Gel ◽  
Gel System

scholarly journals Comparative Study to Investigate the Effect of Meloxicam or Minocycline HCl In Situ Gel System on Local Treatment of Periodontal Pockets

2014 ◽  
Vol 15 (4) ◽  
pp. 1021-1028 ◽  
Author(s):  
Abeer Ahmed Kassem ◽  
Fatma Ahmed Ismail ◽  
Vivian Fahim Naggar ◽  
Elsayed Aboulmagd
Keyword(s):  
Comparative Study ◽  
Local Treatment ◽  
In Situ Gel ◽  
Gel System

scholarly journals Ocular in situ gel: An overview

2019 ◽  
Vol 9 (1) ◽  
pp. 337-347 ◽  
Author(s):  
Asmat Majeed ◽  
Nisar Ahmad Khan
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Ocular Drug Delivery ◽  
The Body ◽  
Drug Bioavailability ◽  
In Situ Gel ◽  
In Situ Gelling ◽  
Gel System

Eye is the most sensitive organ of the body. Designing of ocular drug delivery system is the  most challenging field for pharmaceutical scientists as less than 5% of administered drug enters the eye due to the complicated anatomical structure of the eye, small absorptive surface and low transparency of the cornea, lipophilicity of corneal epithelium, pre corneal loss (due to nasolacrimal drainage), bonding of the drug with proteins contained in tear fluid, blinking, low capacity of conjunctival sac, that restricts the entry of drug molecule at the site of action and ultimately leads to poor ocular therapy. To improve ophthalmic drug bioavailability, there are considerable efforts directed towards newer drug delivery systems for ophthalmic administration. These novel drug delivery systems offer manifold advantages over conventional systems as they increase the efficiency of drug delivery by improving the release profile and also reduce drug toxicity. A lot of research going on in this area proves the fact that in situ gelling systems can be beneficial in the ocular drug delivery. In situ gel forming systems are drug delivery systems that are in solution form before administration in the body but once administered, undergo  in situ gelation, to form a gel triggered by external stimulus such as temperature, pH etc.  This review is to Specify a brief summary about in situ gels, various approaches for in situ gelling systems, different types of polymers used in in situ gels, their mechanisms of gel formation and evaluation of polymeric in situ gel. Keywords: in situ gel, polymers, Temperature induced in situ gel system, pH induced in situ gel system, Ion activated systems.

Studies of Charge Transport Properties in P3HT/ZnO Composites Using Photoinduced Charge Extraction by Linearly Increasing Voltage Technique

2008 ◽  
Vol 1091 ◽  
Author(s):  
Vijila Chellappan ◽  
Furong Zhu ◽  
Minghui Liu ◽  
Kian Ping Loh
Keyword(s):  
Zinc Oxide ◽  
Electric Field ◽  
Charge Transport ◽  
Transport Properties ◽  
Room Temperature ◽  
Zno Nanoparticle ◽  
Nano Particle ◽  
Electric Field Dependence ◽  
Charge Extraction ◽  
Photoinduced Charge

AbstractThe charge transport properties in a mixture of regio-regular (poly 3-hexylthiophene) (RR-P3HT) and Zinc Oxide nano particle (ZnO) have been studied using the photoinduced charge extraction by linearly increasing voltage (PhotoCELIV) technique. We have studied the effect of ZnO nanoparticle size (12 nm and 50 nm) on the charge transport properties by fixing the composition ratio of P3HT/ZnO hybrid. The PhotoCELIV mobility in P3HT/50nm-ZnO at room temperature is found to be 7.8×10−5cm2/Vs at an applied electric field of 2.5 × 104 V/cm, which increases to 1.7×10−4cm2/Vs for P3HT/12nm-ZnO composite. The temperature and electric field dependence of charge mobility in these composites have been studied and analysed using Gaussian disorder formalism. The obtained results suggest that the charge transport properties in P3HT/ZnO composite, at low ZnO concentrations, can be tuned by varying the size of the nanoparticle.

Injectable Chitosan Carrier for Demineralized Bone Matrix

2007 ◽  
Vol 342-343 ◽  
pp. 177-180
Author(s):  
Yu Han Kim ◽  
Mi Hee Cho ◽  
In Bum Song ◽  
Hoon Hyun ◽  
Jung Won Lee ◽  
...  
Keyword(s):  
Room Temperature ◽  
Demineralized Bone Matrix ◽  
Bone Matrix ◽  
Chitosan Solution ◽  
Glycerol Phosphate ◽  
In Situ Gel ◽  
Gel Phase ◽  
Demineralized Bone

In this study, we developed an injectable carrier for demineralized bone matrix (DBM) which consists of chitosan and glycerol phosphate (GP). The phase transition behaviors of chitosan and GP solution characterized as a function of temperature. The chitosan and GP solutions were shown to form a sol at room temperature, and the chitosan solution with 10-20 wt% concentrations were found to undergo sol-to-gel phase transitions as the temperature was increased. In situ gel forming implant in vivo was successfully fabricated by simple subcutaneous injection of chitosan and GP solutions with demineralized bone matrix (DBM). von Kossa images of the gel implant formed from solution with DBM revealed the presence of mineral deposits.

scholarly journals Formulation and Evaluation of A Nanoparticle Laden in Situ Gel System for Enhancing the Ocular Delivery of Ciprofloxacin

2021 ◽  
Vol 70 (2) ◽  
Author(s):  
Sourav Datta ◽  
Ratul Bhowmik ◽  
Ranajit Nath ◽  
Rajarshi Chakraborty ◽  
Apala Chakraborty
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Entrapment Efficiency ◽  
Topical Administration ◽  
Average Particle ◽  
Eye Drops ◽  
Physiological Factors ◽  
In Situ Gel ◽  
Gel System

The human eye can be a tricky issue for topical administration of the drugs due to its unique anatomical arrangements of surface tissue and corneal impermeability. Topical instillation of drugs in the form of eye drops is the major and well-accepted route of administration for the treatment of varied eye disorders. Conventional ophthalmic drug delivery systems often lead to poor bioavailability and thus reduced therapeutic response. Several new preparations are developed to enhance the contact time of the medicament on the surface of the eye. Successful results have been obtained in the form of inserts and collagen shields. However, these preparations have also some disadvantages, such as poor patient compliance, particularly in the case of elderly patients. These problems could be solved by using nanoparticles laden in situ gel-forming systems that exhibit phase transition from solution to gel. These nanoparticle in situ gel systems may be formulated as eye drops suitable for administration through instillation into the eye, which upon exposure to the eye, stimulated by various ocular physiological factors, converts to the gel phase. The advantage of those formulations is that unlike inserts and films they do not require complicated equipment for manufacture and that they are scalable without any difficulty. The objective of the present study was to prepare a pH-dependent nanoparticle-laden in situ gel system for Ciprofloxacin, to prolong the release of the drug into the ocular compartment. No incompatibility was found between the drug and the excipients. Nanoparticles were developed using the nanoprecipitation technique. Eudragit RL 100 was used as the polymer. While the in situ gel solution was formulated using chitosan as polymer. The Ciprofloxacin nanoparticles were measured for particle size and the average particle size was ranged from 295.3-458.7 nm. Entrapment efficiency ranged from 13.83% to 6.29%. Nanoparticleladen in situ gels had the pH of the formulati

scholarly journals An Injectable Sustained Release Lipid Based in situ Gel System of Aripiprazole for the Management of Schizophrenia

2020 ◽  
Vol 12 (4) ◽  
pp. 303-308
Author(s):  
Ashish Raghuvanshi ◽  
Urooj Ahmed Khan ◽  
Uzma Parveen ◽  
Anshul Gupta ◽  
Gaurav Kumar Jain
Keyword(s):  
Sustained Release ◽  
In Situ Gel ◽  
Gel System

scholarly journals In Situ Spectroelectrochemical Investigation of Perovskite Quantum Dots for Tracking Their Transformation

2021 ◽  
Vol 8 ◽  
Author(s):  
ChaeHyun Lee ◽  
Kyoungsoo Kim ◽  
YeJi Shin ◽  
Donghoon Han ◽  
Seog Joon Yoon
Keyword(s):  
Quantum Dots ◽  
Charge Transport ◽  
Precursor State ◽  
Light Emitting ◽  
Mediated Electrochemical Oxidation ◽  
Perovskite Quantum Dots ◽  
Application Potential ◽  
Photoinduced Charge ◽  
Lead Halide

All-inorganic lead-halide perovskite quantum dots (PQDs) (CsPbX3, where X is Cl, Br, or I) have been used successfully in optoelectronic applications, such as solar cells, light-emitting diodes, photocatalysts, and lasers. These PQDs work under electrochemical bias and/or illumination with charge separation/collection by interacting with the charge-transport medium. In this study, we discuss the spectroelectrochemical characteristics of PQDs to understand the oxidation and reduction processes that occur during photoinduced charge transport or charge injection under electrochemical conditions. We also found that the PQDs underwent irreversible transformation to the precursor state of plumbate complexes under electrochemical conditions. Furthermore, in situ spectroelectrochemical analysis demonstrated that hole-mediated electrochemical oxidation of PQDs resulted in their irreversible transformation. Finally, the results presented herein contribute to our understanding of the charge-transfer-mediated process in PQDs and enhance their application potential in optoelectronic devices.

Amelioration from the ocular irritant Capsaicin: development and assessment of a Capsazepine in situ gel system for ocular delivery

2020 ◽  
Vol 17 (6) ◽  
pp. 863-880
Author(s):  
Harshita Krishnatreyya ◽  
Hemanga Hazarika ◽  
Achintya Saha ◽  
Santa Mandal ◽  
Nilutpal Sharma Bora ◽  
...  
Keyword(s):  
Ocular Delivery ◽  
In Situ Gel ◽  
Gel System

scholarly journals Potential of Stimuli-Responsive In Situ Gel System for Sustained Ocular Drug Delivery: Recent Progress and Contemporary Research

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1340
Author(s):  
Manisha Pandey ◽  
Hira Choudhury ◽  
Azila binti Abd Aziz ◽  
Subrat Kumar Bhattamisra ◽  
Bapi Gorain ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Delivery System ◽  
Ocular Drug Delivery ◽  
Eye Drops ◽  
Stimuli Responsive ◽  
In Situ Gel ◽  
In Vivo Models ◽  
The World ◽  
Gel System

Eyesight is one of the most well-deserved blessings, amid all the five senses in the human body. It captures the raw signals from the outside world to create detailed visual images, granting the ability to witness and gain knowledge about the world. Eyes are exposed directly to the external environment; they are susceptible to the vicissitudes of diseases. The World Health Organization has predicted that the number of individuals affected by eye diseases will rise enormously in the next decades. However, the physical barriers of the eyes and the problems associated with conventional ocular formulations are significant challenges in ophthalmic drug development. This has generated the demand for a sustained ocular drug delivery system, which serves to deliver effective drug concentration at a reduced frequency for consistent therapeutic effect and better patient treatment adherence. Recent advancement in pharmaceutical dosage design has demonstrated that a stimuli-responsive in situ gel system exhibits the favorable characteristics for providing sustained ocular drug delivery and enhanced ocular bioavailability. Stimuli-responsive in situ gels undergo a phase transition (solution–gelation) in response to the ocular environmental temperature, pH, and ions. These stimuli transform the formulation into a gel at the cul de sac to overcome the shortcomings of conventional eye drops, such as rapid nasolacrimal drainage and short contact time with the ocular surface This review highlights the recent successful research outcomes of stimuli-responsive in situ gelling systems in treating in vivo models with glaucoma and various ocular infections. Additionally, it also presents the mechanism, recent development, and safety considerations of stimuli-sensitive in situ gel as the potential sustained ocular delivery system for treating common eye disorders.

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