Survey of supercritical fluid techniques for producing drug delivery systems for a potential use in cancer therapy

2016 ◽  
Vol 32 (5) ◽  
Author(s):  
Antonio Tabernero ◽  
Álvaro González-Garcinuño ◽  
Miguel A. Galán ◽  
Eva M. Martín del Valle

AbstractStandard drug delivery systems for cancer treatment usually comprise a device with a specific size and shape (depending on the type of cancer that has to be treated), which is composed by a biodegradable compound with a chemotherapeutic entrapped within it. This device should have a molecule (mainly a protein) bound to its surface to target only cancer cells. On the contrary, supercritical fluids (SCF) have been widely used in the pharmaceutical industry for creating drug delivery systems or for extracting drugs from natural sources. This review explains the potential of SCFs for cancer therapies by studying the current uses of the different high-pressure processes that can be useful for this medical treatment, such as the development of new drug delivery systems (with their drug release) or the extraction of chemotherapeutics from a vegetal matrix.

2021 ◽  
Author(s):  
Sushant Kumar ◽  
Swarnima Pandey ◽  
NV Satheesh Madhav

Polymers are the key material in design of drug delivery systems. These have been shown as the spine for drug development process. These accept an essential part in rising of novel drug delivery systems to crush different intricacies in drug delivery. These are used for controlling the appearance of the drug in needed manner. The hydrophilic and lipophilic polymers are the most ideal choice for getting the ideal conveyance in controlled, manner at the target sites. Isolated of this, these fabricated and semisynthetic polymers are made by different chemical reactions and purification measures. Since these are prepared by different unit operations which are costly. By and by days different investigates are being examined for avoiding the characteristic, physiological and reasonable issues related with the synthetic and semisynthetic polymers. So an alternative rather than synthetic and semisynthetic polymers are being investigated having interest, probability, and any leftover benefits with least troublesome ramifications for environment and physiology of the people. One of the alternatives as opposed to designed and semisynthetic polymers is biopolymers which have pulled in the thought of researchers by using an economical procedures. Biopolymers are novel, adroit and sharp polymers which have been confined from various basic sources. Biopolymers isolated from natural sources might be utilized as novel excipients having a polymeric nature. These isolated biopolymers have superb bioretardant, bio stabilizer, and mucoadhesive properties. These have the brilliant film-framing capacity and biocompatibility properties. The isolated bio-polymers have great drug release rate controlling capacities. Since these are biodegradable and might be utilized as an option in contrast to standard manufactured synthetic and semisynthetic polymers. The isolated biopolymer shows critical biodegradable, mucoadhesive, filmability, and retardability properties which are like properties of standard polymers, may be the alternative in design of novel drug delivery system design.


Author(s):  
Anamika Saxena Saxena ◽  
Santosh Kitawat ◽  
Kalpesh Gaur ◽  
Virendra Singh

The main goal of any drug delivery system is to achieve desired concentration of the drug in blood or tissue, which is therapeutically effective and nontoxic for a prolonged period. Various attempts have been made to develop gastroretentive delivery systems such as high density system, swelling, floating system. The recent developments of FDDS including the physiological and formulation variables affecting gastric retention, approaches to design single-unit and multiple-unit floating systems, and their classification and formulation aspects are covered in detail. Gastric emptying is a complex process and makes in vivo performance of the drug delivery systems uncertain. In order to avoid this variability, efforts have been made to increase the retention time of the drug-delivery systems for more than 12 hours. The floating or hydrodynamically controlled drug delivery systems are useful in such application. Background of the research: Diltiazem HCL (DTZ), has short biological half life of 3-4 h, requires rather high frequency of administration. Due to repeated administration there may be chances of patient incompliance and toxicity problems. Objective: The objective of study was to develop sustained release alginate beads of DTZ for reduction in dosing frequency, high bioavailability and better patient compliance. Methodology: Five formulations prepared by using different drug to polymer ratios, were evaluated for relevant parameters and compared. Alginate beads were prepared by ionotropic external gelation technique using CaCl2 as cross linking agent. Prepared beads were evaluated for % yield, entrapment efficiency, swelling index in 0.1N HCL, drug release study and SEM analysis. In order to improve %EE and drug release, LMP and sunflower oil were used as copolymers along with sodium alginate.


2020 ◽  
Vol 21 (11) ◽  
pp. 1084-1098
Author(s):  
Fengqian Chen ◽  
Yunzhen Shi ◽  
Jinming Zhang ◽  
Qi Liu

This review summarizes the epigenetic mechanisms of deoxyribonucleic acid (DNA) methylation, histone modifications in cancer and the epigenetic modifications in cancer therapy. Due to their undesired side effects, the use of epigenetic drugs as chemo-drugs in cancer therapies is limited. The drug delivery system opens a door for minimizing these side effects and achieving greater therapeutic benefits. The limitations of current epigenetic therapies in clinical cancer treatment and the advantages of using drug delivery systems for epigenetic agents are also discussed. Combining drug delivery systems with epigenetic therapy is a promising approach to reaching a high therapeutic index and minimizing the side effects.


2020 ◽  
Vol 17 ◽  
Author(s):  
Neeraj Mittal ◽  
Varun Garg ◽  
Sanjay Kumar Bhadada ◽  
O. P. Katare

: The corona virus disease 2019 (COVID-19) has found its roots from Wuhan (China). COVID-19 is caused by a novel corona virus SARS-CoV2, previously named as 2019-nCoV. COVID-19 has spread across the globe and declared as pandemic by World health organization (WHO) on 11th March, 2020. Currently, there is no standard drug or vaccine available for the treatment, so repurposing of existing drugs is the only solution. Novel drug delivery systems (NDDS) will be boon for the repurposing of drugs. The role of various NDDS in repurposing of existing drugs for treatment of various viral diseases and their relevance in COVID-19 has discussed in this paper. It focuses on the currently ongoing research in the implementation of NDDS in COVID-19. Moreover it describes the role of NDDS in vaccine development for COVID-19. This paper also emphasizes how NDDS will help to develop the improved delivery systems (dosage forms) of existing therapeutic agents and also explore the new insights to find out the void spaces for a potential targeted delivery. So in these tough times, NDDS and nanotechnology can be a safeguard to humanity.


2018 ◽  
Vol 18 (10) ◽  
pp. 857-880 ◽  
Author(s):  
Salma E. Ahmed ◽  
Nahid Awad ◽  
Vinod Paul ◽  
Hesham G. Moussa ◽  
Ghaleb A. Husseini

Conventional chemotherapeutics lack the specificity and controllability, thus may poison healthy cells while attempting to kill cancerous ones. Newly developed nano-drug delivery systems have shown promise in delivering anti-tumor agents with enhanced stability, durability and overall performance; especially when used along with targeting and triggering techniques. This work traces back the history of chemotherapy, addressing the main challenges that have encouraged the medical researchers to seek a sanctuary in nanotechnological-based drug delivery systems that are grafted with appropriate targeting techniques and drug release mechanisms. A special focus will be directed to acoustically triggered liposomes encapsulating doxorubicin.


2018 ◽  
Vol 14 (5) ◽  
pp. 432-439 ◽  
Author(s):  
Juliana M. Juarez ◽  
Jorgelina Cussa ◽  
Marcos B. Gomez Costa ◽  
Oscar A. Anunziata

Background: Controlled drug delivery systems can maintain the concentration of drugs in the exact sites of the body within the optimum range and below the toxicity threshold, improving therapeutic efficacy and reducing toxicity. Mesostructured Cellular Foam (MCF) material is a new promising host for drug delivery systems due to high biocompatibility, in vivo biodegradability and low toxicity. Methods: Ketorolac-Tromethamine/MCF composite was synthesized. The material synthesis and loading of ketorolac-tromethamine into MCF pores were successful as shown by XRD, FTIR, TGA, TEM and textural analyses. Results: We obtained promising results for controlled drug release using the novel MCF material. The application of these materials in KETO release is innovative, achieving an initial high release rate and then maintaining a constant rate at high times. This allows keeping drug concentration within the range of therapeutic efficacy, being highly applicable for the treatment of diseases that need a rapid response. The release of KETO/MCF was compared with other containers of KETO (KETO/SBA-15) and commercial tablets. Conclusion: The best model to fit experimental data was Ritger-Peppas equation. Other models used in this work could not properly explain the controlled drug release of this material. The predominant release of KETO from MCF was non-Fickian diffusion.


2018 ◽  
Vol 244 (4) ◽  
pp. 283-293 ◽  
Author(s):  
Stephen J. Jones ◽  
Annette F. Taylor ◽  
Paul A Beales

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.”


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