scholarly journals Cellulosic Polymers for Enhancing Drug Bioavailability in Ocular Drug Delivery Systems

2021 ◽  
Vol 14 (11) ◽  
pp. 1201
Author(s):  
Bharti Gupta ◽  
Varsha Mishra ◽  
Sankalp Gharat ◽  
Munira Momin ◽  
Abdelwahab Omri
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Aqueous Solubility ◽  
Class Ii ◽  
Delivery Systems ◽  
Solubility Enhancement ◽  
Ocular Drug Delivery ◽  
Drug Bioavailability ◽  
Bcs Class Ii ◽  
Cellulosic Polymers

One of the major impediments to drug development is low aqueous solubility and thus poor bioavailability, which leads to insufficient clinical utility. Around 70–80% of drugs in the discovery pipeline are suffering from poor aqueous solubility and poor bioavailability, which is a major challenge when one has to develop an ocular drug delivery system. The outer lipid layer, pre-corneal, dynamic, and static ocular barriers limit drug availability to the targeted ocular tissues. Biopharmaceutical Classification System (BCS) class II drugs with adequate permeability and limited or no aqueous solubility have been extensively studied for various polymer-based solubility enhancement approaches. The hydrophilic nature of cellulosic polymers and their tunable properties make them the polymers of choice in various solubility-enhancement techniques. This review focuses on various cellulose derivatives, specifically, their role, current status and novel modified cellulosic polymers for enhancing the bioavailability of BCS class II drugs in ocular drug delivery systems.

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 NIOSOMES AS AN APPROACH TO IMPROVE THE SOLUBILITY AND BIOAVAILABILITY OF BCS CLASS II DRUGS

2021 ◽  
pp. 94-101
Author(s):  
GAURANG SAWANT ◽  
GEETA BHAGWAT
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Class Ii ◽  
Delivery Systems ◽  
Solubility In Water ◽  
Bcs Class Ii ◽  
Rate Limiting Step ◽  
Rate Limiting ◽  
Low Solubility ◽  
Biopharmaceutics Classification

Based on their solubility and permeability, drugs are typically divided into four classes (Classes I–IV) according to the biopharmaceutics classification system (BCS). Of these classes, BCS class II drugs have high permeability and low solubility; not only do these characteristics constitute the rate-limiting step in the formulation of these drugs but the low solubility in water results in low bioavailability. Thus, methods for improving their solubility have been developed using lipid carriers such as liposomes, niosomes, and aquasomes; other approaches include self-micro-emulsifying drug delivery systems (SMEDDS) and self-nano-emulsifying drug delivery systems (SNEDDS). Currently, niosome-based drug delivery systems that utilize nonionic surfactants, drugs, and cholesterol in varying ratios are being widely used to deliver both hydrophilic and lipophilic drugs in addition to several other applications of niosomes.

Nanoscale Drug Delivery Systems for Glaucoma: Experimental and In Silico Advances

2020 ◽  
Vol 20 ◽  
Author(s):  
Smriti Sharma ◽  
Vinayak Bhatia
Keyword(s):  
Drug Delivery ◽  
In Silico ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Ocular Drug Delivery ◽  
The Body ◽  
Single Wall Carbon Nanotubes ◽  
Blood Retinal Barrier ◽  
Novel Drugs ◽  
Blood Aqueous Barrier

: In this review nanoscale based drug delivery systems particularly in relevance to the antiglaucoma drugs have been discussed. In addition to that, the latest computational/in silico advances in this field are examined in brief. Using nanoscale materials for drug delivery, is an ideal option to target tumours and drug can be released at areas of the body where traditional drugs may fail to act. Nanoparticles, polymeric nanomaterials, single-wall carbon nanotubes (SWCNTs), quantum dots (QDs), liposomes and graphene are the most important nanomaterials used for drug delivery. Ocular drug delivery is one of the most common and difficult tasks faced by pharmaceutical scientists because of many challenges like circumventing the blood–retinal barrier, corneal epithelium and the blood–aqueous barrier. Authors found compelling empirical evidence of scientists relying on in-silico approaches to develop novel drugs and drug delivery systems for treating glaucoma. This review in nanoscale drug delivery systems will help us in understand the existing queries and evidence gaps and will pave way for effective design of novel ocular drug delivery systems

Self-microemulsion Technology for Water-insoluble Drug Delivery

2019 ◽  
Vol 15 (6) ◽  
pp. 576-588 ◽  
Author(s):  
Beibei Yan ◽  
Yu Gu ◽  
Juan Zhao ◽  
Yangyang Liu ◽  
Lulu Wang ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Aqueous Solubility ◽  
Delivery Systems ◽  
Poorly Soluble Drugs ◽  
New Chemical Entities ◽  
Poorly Soluble ◽  
Water Insoluble Drug ◽  
Semi Solid ◽  
Solidification Technology

: According to the drug discovery, approximately 40% of the new chemical entities show poor bioavailability due to their low aqueous solubility. In order to increase the solubility of the drugs, self-micro emulsifying drug delivery systems (SMEDDS) are considered as an ideal technology for enhancing the permeability of poorly soluble drugs in GI membranes. The SMEDDS are also generally used to enhance the oral bioavailability of the hydrophobic drugs. At present, most of the self-microemulsion drugs are liquid dosage forms, which could cause some disadvantages, such as the low bioavailability of the traditional liquid SMEDDS. Therefore, solid self-micro emulsifying drug delivery systems (S-SMEDDS) have emerged widely in recent years, which were prepared by solidifying a semi-solid or liquid self-emulsifying (SE) ingredient into a powder in order to improve stability, treatment and patient compliance. The article gives a comprehensive introduction of the study of SMEDDS which could effectively tackle the problem of the water-insoluble drug, especially the development of solidification technology of SMEDDS. Finally, the present challenges and the prospects in this field were also discussed.

A Review on Formulation and Development of Solid Self-Nano Emulsifying Drug Delivery Systems

2021 ◽  
Vol 14 (4) ◽  
pp. 5519-5228
Author(s):  
Sunitha M Reddy ◽  
Sravani Baskarla
Keyword(s):  
Drug Delivery ◽  
Dissolution Rate ◽  
Drug Delivery System ◽  
Delivery System ◽  
Drug Delivery Systems ◽  
Water Solubility ◽  
Drug Loading ◽  
Aqueous Solubility ◽  
Delivery Systems ◽  
Particle Size Reduction

This article describes current strategies to enhance aqueous solubility and dissolution rate of poor soluble drugs. Most drugs in the market are lipophilic with low or poor water solubility. There are various methods to enhance solubility: co-solvency, particle size reduction, salt formation and Self Nanoemulsifying drug delivery systems, SEDDS is a novel approach to enhance solubility, dissolution rate and bioavailability of drugs. The study involves formulation and evaluation of solid self-Nano emulsifying drug delivery system (S-SNEDDS) to enhance aqueous solubility and dissolution rate. Oral route is the most convenient route for non-invasive administration. S-SNEDDS has more advantages when compared to the liquid self-emulsifying drug delivery system. Excipients were selected depends upon the drug compatibility oils, surfactants and co surfactants were selected to formulate Liquid SNEDDS these formulated liquid self-nano emulsifying drug delivery system converted into solid by the help of porous carriers, Melted binder or with the help of drying process. Conversion process of liquid to solid involves various techniques; they are spray drying; freeze drying and fluid bed coating technique; extrusion, melting granulation technique. Liquid SNEDDS has a high ability to improve dissolution and solubility of drugs but it also has disadvantages like incompatibility, decreased drug loading, shorter shelf life, ease of manufacturing and ability to deliver peptides that are prone to enzymatic hydrolysis.  

scholarly journals Towards feedback-controlled nanomedicines for smart, adaptive delivery

2018 ◽  
Vol 244 (4) ◽  
pp. 283-293 ◽  
Author(s):  
Stephen J. Jones ◽  
Annette F. Taylor ◽  
Paul A Beales
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
The Body ◽  
Living Systems ◽  
Prolonged Release ◽  
Drug Bioavailability ◽  
Drug Release Profile ◽  
Chemical Systems

Nanomedicines for controlled drug release provide temporal and spatial regulation of drug bioavailability in the body. The timing of drug release is usually engineered either for slow gradual release over an extended period of time or for rapid release triggered by a specific change in its physicochemical environment. However, between these two extremes, there is the desirable possibility of adaptive nanomedicines that dynamically modulate drug release in tune with its changing environment. Adaptation and response through communication with its environment is a fundamental trait of living systems; therefore, the design of biomimetic nanomedicines through the approaches of bottom-up synthetic biology provides a viable route to this goal. This could enable drug delivery systems to optimize release in synchronicity with the body’s natural biological rhythms and the personalized physiological characteristics of the patient, e.g. their metabolic rate. Living systems achieve this responsiveness through feedback-controlled biochemical processes that regulate their functional outputs. Towards this goal of adaptive drug delivery systems, we review the general benefits of nanomedicine formulations, provide existing examples of experimental nanomedicines that encapsulate the metabolic function of enzymes, and give relevant examples of feedback-controlled chemical systems. These are the underpinning concepts that hold promise to be combined to form novel adaptive release systems. Furthermore, we motivate the advantages of adaptive release through chronobiological examples. By providing a brief review of these topics and an assessment of the state of the art, we aim to provide a useful resource to accelerate developments in this field. Impact statement The timing and rate of release of pharmaceuticals from advanced drug delivery systems is an important property that has received considerable attention in the scientific literature. Broadly, these mostly fall into two classes: controlled release with a prolonged release rate or triggered release where the drug is rapidly released in response to an environmental stimulus. This review aims to highlight the potential for developing adaptive release systems that more subtlety modulate the drug release profile through continuous communication with its environment facilitated through feedback control. By reviewing the key elements of this approach in one place (fundamental principles of nanomedicine, enzymatic nanoreactors for medical therapies and feedback-controlled chemical systems) and providing additional motivating case studies in the context of chronobiology, we hope to inspire innovative development of novel “chrononanomedicines.”

Unique Ocular Drug Delivery Systems

2013 ◽  
pp. 73-73
Author(s):  
Xiadong Zheng ◽  
Ashim Mitra ◽  
James Hill ◽  
Marg Marquart
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Ocular Drug Delivery
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