scholarly journals OCULAR DRUG DELIVERY SYSTEM: CHALLENGES AND APPROACHES

2020 ◽  
pp. 49-57
Author(s):  
VISHAL KUMAR RAJ ◽  
RUPA MAZUMDER ◽  
MONIKA MADHRA
Keyword(s):  
Drug Delivery ◽  
Delivery System ◽  
Delivery Systems ◽  
Ocular Drug Delivery ◽  
Penetration Enhancers ◽  
Non Invasive ◽  
Novel Delivery Systems ◽  
Ocular Delivery System ◽  
Ocular Therapy

The ocular drug delivery deviates through a number of anatomical and physiological barriers, which have been a bottleneck for the ophthalmologists. The ocular barriers, static and dynamic, decrease the absorption of the therapeutic agents and the entry of the xenobiotics. Thus, a conventional ocular dosage form has various disadvantages of its use in ocular diseases. Hence, an ideal ocular delivery system has always been aimed, where the bioavailability of a drug is maintained for a longer period of time. The present review aims to focus on the drawbacks of the conventional ocular therapy and the advantages of designing novel delivery systems, with their certain specific advantages in ocular pharmacokinetics and the enhancement of bioavailability. These novel approaches emphasize on the benefits of various ocular drug delivery systems, like eye ointments, gels and use of viscosity enhancers, prodrugs, penetration enhancers, microparticles, liposomes, niosomes, ocular inserts, implants, intravitreal injections, nanoparticles, nanosuspension, microemulsion, dendrimers, in situ gels, iontophoresis and periocular injections. The compiled data presented in this review will act as a good information resource and reference point for further researches in the field of ocular drug delivery aiming non-invasive sustained release of drugs in the anterior and posterior segments of the eye.

Injectable,in situ forming poly(propylene fumarate)-based ocular drug delivery systems

2007 ◽  
Vol 83A (3) ◽  
pp. 656-666 ◽  
Author(s):  
H. Ueda ◽  
M.C. Hacker ◽  
A. Haesslein ◽  
S. Jo ◽  
D.M. Ammon ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Ocular Drug Delivery ◽  
In Situ Forming ◽  
Poly Propylene

scholarly journals Development and Characterization of 99mTc-timolol Maleate for Evaluating Efficacy of In Situ Ocular Drug Delivery System

2009 ◽  
Vol 10 (2) ◽  
pp. 540-546 ◽  
Author(s):  
Himanshu Gupta ◽  
M. Aqil ◽  
R. K. Khar ◽  
Asgar Ali ◽  
Aseem Bhatnagar ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Delivery System ◽  
Ocular Drug Delivery ◽  
Timolol Maleate

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.

scholarly journals Combination of Nanomicellar Technology and In Situ Gelling Polymer as Ocular Drug Delivery System (ODDS) for Cyclosporine-A

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 192
Author(s):  
Eleonora Terreni ◽  
Erica Zucchetti ◽  
Silvia Tampucci ◽  
Susi Burgalassi ◽  
Daniela Monti ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Delivery System ◽  
Cyclosporine A ◽  
Sol Gel ◽  
Ocular Drug Delivery ◽  
Water Soluble ◽  
Glycol Succinate ◽  
In Situ Gelling

A combination of in situ gelling systems and a loaded drug self-assembling nanomicellar carrier was chosen in this study as a new potential Ocular Drug Delivery System (ODDS) for Cyclosporine-A (CyA), a poorly water-soluble drug. Two non-ionic surfactants (d-α-tocopherol polyethylene glycol succinate, VitE-TPGS and polyoxyl 40 hydrogenated castor oil, RH-40) were used to produce the nanomicelles. The physical–chemical characterization of the nanomicelles in terms of CyA entrapment (EE%) and loading efficiency (LE%), cloud point (CP), regeneration time (RT), size and polydispersity index (PI) allowed us to select the best combination of surfactant mixture, which showed appropriate stability, high CyA-EE (99.07%), very small and homogeneous dimensions and favored the solubilization of an amount of CyA (0.144% w/w) comparable to that contained in marketed emulsion Ikervis®. The selected nanomicellar formulation incorporated into optimized ion-sensitive polymeric dispersions of gellan gum (GG-LA: 0.10, 0.15 and 0.20% w/w) able to trigger the sol–gel transition after instillation was characterized from technological (osmolality, pH, gelling capacity, rheological behavior, wettability, TEM and storage stability at 4 and 20 °C) and biopharmaceutical points of view. This new combined approach allowed us to obtain clear aqueous dispersions that were easy to instill and able to form a viscous gel when in contact with the tear fluid, improving CyA ocular bioavailability. Furthermore, this new ODDS prevented CyA transcorneal permeation, exhibited low cytotoxicity and prolonged the CyA resident time in the precorneal area compared to Ikervis®.

scholarly journals In-Situ Forming Polymeric Drug Delivery Systems for Ophthalmic Use: An Overview

2021 ◽  
Vol 11 (3-S) ◽  
pp. 98-103
Author(s):  
Pranal Chhetri ◽  
Prithviraj Chakraborty ◽  
Debasmita Das ◽  
Tamanna Afnan
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Ocular Drug Delivery ◽  
Eye Drops ◽  
In Situ Forming ◽  
Resident Time ◽  
Ocular Bioavailability ◽  
Polymeric Drug Delivery Systems

Delivery of drug into the ocular region is hindered by the protective layers that encapsulate the eyes, it has always been a major problem to get an effective bioavailability of the active drug in the ocular region due to the low precorneal resident time of most of the ocular delivery systems specifically convention once such as ointment, solution and suspension, as a result, most of the delivery systems are not capable of effectively treating ocular diseases. Several works have and are being carried out to overcome this problem one of which is using in-situ forming polymeric systems. Ocular In-situ gelling systems are a novel class of ocular drug delivery systems that are initially in a solution form but instantaneously gets converted into a viscous gel upon introduction or installation in the ocular cavity from which the active drugs get released in a sustained manner. This sol-to-gel phase transition depends upon various factors like change in pH, ion presence and change in temperature. Gel formed after the transformation has preferred viscosity along with bio-adhesive property, which increases the gel’s resident time in the ocular area and also releases the drug in a prolonged and sustained manner unlike conventional eye drops and ointments. This review emphasizes various ocular in-situ systems namely, pH triggered, Ion activated, and Temperature triggered systems which have prolonged residence time in the cul-de-sac area of the eye, hence increasing the ocular bioavailability. Keywords: In-situ gel, Ocular Drug delivery, Ocular Bioavailability, Polymer

scholarly journals A Novel Carbon Dots/Thermo-Sensitive In Situ Gel for a Composite Ocular Drug Delivery System: Characterization, Ex-Vivo Imaging and In Vivo Evaluation

2021 ◽  
Vol 22 (18) ◽  
pp. 9934
Author(s):  
Lijie Wang ◽  
Hao Pan ◽  
Donghao Gu ◽  
Haowei Sun ◽  
Kai Chen ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Delivery System ◽  
Retention Time ◽  
Carbon Dots ◽  
Ex Vivo ◽  
Ocular Drug Delivery ◽  
Ocular Tissues ◽  
In Situ Gel

We developed a potential composite ocular drug delivery system for the topical administration of diclofenac sodium (DS). The novel carbon dot CDC-HP was synthesized by the pyrolysis of hyaluronic acid and carboxymethyl chitosan through a one-step hydrothermal method and then embedded in a thermosensitive in situ gel of poloxamer 407 and poloxamer 188 through swelling loading. The physicochemical characteristics of these carbon dots were investigated. The results of the in vitro release test showed that this composite ocular drug delivery system (DS-CDC-HP-Gel) exhibited sustained release for 12 h. The study of the ex vivo fluorescence distribution in ocular tissues showed that it could be used for bioimaging and tracing in ocular tissues and prolong precorneal retention. Elimination profiles in tears corresponded to the study of ex vivo fluorescence imaging. The area under the curve of DS in the aqueous humor in the DS-CDC-HP-Gel group was 3.45-fold that in the DS eye drops group, indicating a longer precorneal retention time. DS-CDC-HP with a positive charge and combined with a thermosensitive in situ gel might strengthen adherence to the corneal surface and prolong the ocular surface retention time to improve the bioavailability. This composite ocular delivery system possesses potential applications in ocular imaging and drug delivery.

scholarly journals In Situ Gelling Ophthalmic Drug Delivery System for the Optimization of Diagnostic and Preoperative Mydriasis: In Vitro Drug Release, Cytotoxicity and Mydriasis Pharmacodynamics

Pharmaceutics ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 360
Author(s):  
Pierre-Louis Destruel ◽  
Ni Zeng ◽  
Françoise Brignole-Baudouin ◽  
Sophie Douat ◽  
Johanne Seguin ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Delivery System ◽  
Delivery Systems ◽  
Eye Drops ◽  
Active Ingredients ◽  
In Vitro Drug Release ◽  
In Situ Gelling

Mydriasis is required prior to many eye examinations and ophthalmic surgeries. Nowadays, phenylephrine hydrochloride (PHE) and tropicamide (TPC) are extensively used to induce mydriasis. Several pharmaceutic dosage forms of these two active ingredients have been described. However, no optimal therapeutic strategy has reached the market. The present work focuses on the formulation and evaluation of a mucoadhesive ion-activated in situ gelling delivery system based on gellan gum and hydroxyethylcellulose (HEC) for the delivery of phenylephrine and tropicamide. First, in vitro drug release was studied to assess appropriate sustained drug delivery on the ocular surface region. Drug release mechanisms were explored and explained using mathematical modeling. Then, in situ gelling delivery systems were visualized using scanning electron microscopy illustrating the drug release phenomena involved. Afterward, cytotoxicity of the developed formulations was studied and compared with those of commercially available eye drops. Human epithelial corneal cells were used. Finally, mydriasis intensity and kinetic was investigated in vivo. Mydriasis pharmacodynamics was studied by non-invasive optical imaging on vigilant rabbits, allowing eye blinking and nasolacrimal drainage to occur physiologically. In situ gelling delivery systems mydriasis profiles exhibited a significant increase of intensity and duration compared with those of conventional eye drops. Efficient mydriasis was achieved following the administration of a single drop of in situ gel reducing the required amount of administered active ingredients by four- to eight-fold compared with classic eye drop regimen.

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.

scholarly journals DISCOSOMES: A FUTURISTIC UPHEAVAL IN VESICULAR DRUG DELIVERY

2021 ◽  
pp. 41-46
Author(s):  
AMITHA MARY JOSE ◽  
V. U. LAKSHMI ◽  
GAYATHRI S. ◽  
SREEJA C. NAIR
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Delivery System ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Ocular Drug Delivery ◽  
The Body ◽  
Pharmaceutical Drugs ◽  
Release Formulation ◽  
Sustained Release Formulation

The formulation system employed to convey pharmaceutical drugs compound in the body to attain the desired therapeutic effect at a predetermined rate depending on pharmacological aspects, drug profile, and physiological conditions can be referred to as a novel drug delivery system (NDDS). Due to the intricately sensitive anatomy and physiology of the eye pharmacologist find the ocular delivery system to be more involuted than other routes. Pre-corneal, static and dynamic is the 3 types of ophthalmic barriers, which along with the inflow and outflow of lacrimal fluids, nasolacrimal drainage, are some of the germane factors that affect bioavailability. Unlike conventional dosage forms, where the distribution of drugs in non-targeted body fluids and tissues transcends the quantity of required drug in targeted tissues and causes repercussions, these modified drug delivery systems surpass the ocular barriers and adverse reactions, emphasizing on less invasive, prolonged action. It also promotes sustained release formulation that subjugates the drug loss or degradation to treat many ocular diseases effectively. The current review recapitulates the fundamentals of discosomes, a type of vesicular drug delivery system that acts as a vehicle for the drug delivery of both hydrophilic and lipophilic drugs. Discosomes are giant, disc-shaped structures modified from niosomes by arresting the vesicles at the discosome phase. Due to their idiosyncratic size, it provides all due benefits compared to other ocular drug delivery systems. From the review, it can be culminated that discosomes are a potential subject of opposition and opportunities in the arena of safe and effective ocular drug delivery.

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