Self-Limiting Aggregation By Controlled Ligand-Receptor Stoicfflometry and Its Use For a Novel Drug Delivery System

1999 ◽  
Vol 5 (S2) ◽  
pp. 1212-1213
Author(s):  
E. Kisak ◽  
M. Kennedy ◽  
J. A. Zasadzinski

Lipid vesicles are used as drug delivery vehicles for the slow sustained release of a drug compound to a specific site in the body. This translates to more efficient medication with limited side effects. Although unilamellar drug delivery vesicles have progressed greatly, they are still limited in there applications. Our group has designed a second generation drug release system, the “vesosome“ which incorporates an aggregate of lipid vesicles encapsulated in a second lipid membrane. The two separate membranes can be specialized to allow for increased drug encapsulation and better control over drug release rate, which leads to a more general drug delivery system.Lipid vesicle aggregates were formed by using a ligand-receptor system (biotinated lipids protruding from the vesicle surface crosslinked with streptavidin). The streptavidin/biotin system is one of the strongest in nature, providing specific binding.

Author(s):  
DIPJYOTI BISWAS ◽  
SUDIP DAS ◽  
SOURAV MOHANTO ◽  
SHUBHRAJIT MANTRY

The modified/regulated drug delivery system helps to sustain the delivery of the drug for a prolonged period. The modified drug delivery system is primarily aimed at ensuring protection, the effectiveness of the drug, and patient compliance. The transdermal drug delivery system (TDDS) falls within the modified drug delivery system, in which the goal is to deliver the drug at a fixed dose and regulated rate through the skin. Polymers are the backbone of the framework for providing transdermal systems. The polymer should be stable, non-toxic, economical, and provide a sustainable release of the drug. In general, natural polymers used in the TDDS as rate-controlling agents, protective, and stabilizing agents and also used to minimize the frequency of dosing and improve the drug’s effectiveness by localizing at the site of action. Nowadays, manufacturers are likely to use natural polymers due to many issues associated with drug release and side effects with synthetic polymers. Drug release processes from natural polymers include oxidation, diffusion, and swelling. Natural polymers may be used as the basis to achieve predetermined drug distribution throughout the body. The use of natural materials for traditional and modern types of dosage forms are gums, mucilages, resins, and plant waste etc. Thus, the main objective of this review article is to give a brief knowledge about the extraction, modification, characterization, and biomedical application of conventional natural polymers used in the transdermal drug delivery system and their future prospective.


Author(s):  
ShirishaG. Suddala ◽  
S. K. Sahoo ◽  
M. R. Yamsani

Objective: The objective of this research work was to develop and evaluate the floating– pulsatile drug delivery system (FPDDS) of meloxicam intended for Chrono pharmacotherapy of rheumatoid arthritis. Methods: The system consisting of drug containing core, coated with hydrophilic erodible polymer, which is responsible for a lag phase for pulsatile release, top cover buoyant layer was prepared with HPMC K4M and sodium bicarbonate, provides buoyancy to increase retention of the oral dosage form in the stomach. Meloxicam is a COX-2 inhibitor used to treat joint diseases such as osteoarthritis and rheumatoid arthritis. For rheumatoid arthritis Chrono pharmacotherapy has been recommended to ensure that the highest blood levels of the drug coincide with peak pain and stiffness. Result and discussion: The prepared tablets were characterized and found to exhibit satisfactory physico-chemical characteristics. Hence, the main objective of present work is to formulate FPDDS of meloxicam in order to achieve drug release after pre-determined lag phase. Developed formulations were evaluated for in vitro drug release studies, water uptake and erosion studies, floating behaviour and in vivo radiology studies. Results showed that a certain lag time before drug release which was due to the erosion of the hydrophilic erodible polymer. The lag time clearly depends on the type and amount of hydrophilic polymer which was applied on the inner cores. Floating time and floating lag time was controlled by quantity and composition of buoyant layer. In vivo radiology studies point out the capability of the system of longer residence time of the tablets in the gastric region and releasing the drug after a programmed lag time. Conclusion: The optimized formulation of the developed system provided a lag phase while showing the gastroretension followed by pulsatile drug release that would be beneficial for chronotherapy of rheumatoid arthritis and osteoarthritis.


Pharmaceutics ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 544
Author(s):  
Miao Wang ◽  
Sung-Kyun You ◽  
Hong-Ki Lee ◽  
Min-Gu Han ◽  
Hyeon-Min Lee ◽  
...  

Docetaxel (DTX) has clinical efficacy in the treatment of breast cancer, but it is difficult to develop a product for oral administration, due to low solubility and permeability. This study focused on preparing a self-microemulsifying drug delivery system (SME) loaded with DTX-phospholipid complex (DTX@PLC), to improve the dissolution and gastrointestinal (GI) permeability of DTX. A dual technique combining the phospholipid complexation and SME formulation described as improving upon the disadvantages of DTX has been proposed. We hypothesized that the complexation of DTX with phospholipids can improve the lipophilicity of DTX, thereby increasing the affinity of the drug to the cell lipid membrane, and simultaneously improving permeability through the GI barrier. Meanwhile, DTX@PLC-loaded SME (DTX@PLC-SME) increases the dissolution and surface area of DTX by forming a microemulsion in the intestinal fluid, providing sufficient opportunity for the drug to contact the GI membrane. First, we prepared DTX@PLC-SME by combining dual technologies, which are advantages for oral absorption. Next, we optimized DTX@PLC-SME with nanosized droplets (117.1 nm), low precipitation (8.9%), and high solubility (33.0 mg/g), which formed a homogeneous microemulsion in the aqueous phase. Dissolution and cellular uptake studies demonstrated that DTX@PLC-SME showed 5.6-fold higher dissolution and 2.3-fold higher DTX uptake in Caco-2 cells than raw material. In addition, an ex vivo gut sac study confirmed that DTX@PLC-SME improved GI permeability of DTX by 2.6-fold compared to raw material. These results suggested that DTX@PLC-SME can significantly overcome the disadvantages of anticancer agents, such as low solubility and permeability.


2007 ◽  
Vol 25 (6) ◽  
pp. 1347-1354 ◽  
Author(s):  
Heiko Kranz ◽  
Erol Yilmaz ◽  
Gayle A. Brazeau ◽  
Roland Bodmeier

2018 ◽  
Vol 115 (3) ◽  
pp. 501-506 ◽  
Author(s):  
Meng Qiu ◽  
Dou Wang ◽  
Weiyuan Liang ◽  
Liping Liu ◽  
Yin Zhang ◽  
...  

A biodegradable drug delivery system (DDS) is one the most promising therapeutic strategies for cancer therapy. Here, we propose a unique concept of light activation of black phosphorus (BP) at hydrogel nanostructures for cancer therapy. A photosensitizer converts light into heat that softens and melts drug-loaded hydrogel-based nanostructures. Drug release rates can be accurately controlled by light intensity, exposure duration, BP concentration, and hydrogel composition. Owing to sufficiently deep penetration of near-infrared (NIR) light through tissues, our BP-based system shows high therapeutic efficacy for treatment of s.c. cancers. Importantly, our drug delivery system is completely harmless and degradable in vivo. Together, our work proposes a unique concept for precision cancer therapy by external light excitation to release cancer drugs. If these findings are successfully translated into the clinic, millions of patients with cancer will benefit from our work.


Author(s):  
Harini Amballa ◽  
Navaneetha Kaluva ◽  
Sree Giri Prasad Beri ◽  
Krishna Mohan Chinnala ◽  
Mayuri Konda

Mucoadhesive drug release system is a preferably unidirectional release system where mucosal epithelial exterior is enclosed by the mucus deposit that interacts with the bio-adhesive drug delivery system and swelling time of the buccal dosage form which is amplified by mucin molecules at the location of administration. Eplerenone is an Anti-hypertensive drug that undergoes hepatic first pass metabolism and shows 69% of bioavailability. In order to bypass the hepatic first pass metabolism the drug is designed to be delivered through buccal cavity to avoid the first pass metabolism. Eplerenone buccal tablets were formulated by using direct compression method with different polymers like HPMC K 100M, Carbopol 934P, Carbopol 974P, Xantham Gum, Eudragit L100 and NaCMC in various concentrations and compositions. Incompatibility complications were not observed from the FTIR spectrums. The formulated and prepared buccal solid dosage forms were evaluated for pre-compressions and post- compression parameters such as hardness, weight variation, thickness, friability, surface pH, swelling index, in-vitro dissolution studies, drug content uniformity, mucoadhesion strength and mucoadhesion time. Evaluation results of formulation F12 are proven to be the optimal formulation showing highest mucoadhesion time, mucoadhesion strength and in-vitro drug release for prolonged period of time about 8 hours. Eplerenone is best delivered through buccal drug delivery system to enhance its oral bioavailability and bypass the hepatic first pass metabolism.


Author(s):  
Kanuri Lakshmi Prasad ◽  
Kuralla Hari

Objective: To enhance solubility and dissolution rate of budesonide through development of solid self-nanoemulsifying drug delivery system (S-SNEDDS). Methods: Liquid self-nanoemulsifying drug delivery systems (L-SNEDDS) were prepared and ternary phase diagram was constructed using Origin pro 8. Liquid self-nanoemulsifying formulation LF2 having 20% oil and 80% of surfactant/co-surfactant was optimized from the three formulations (LF1-LF3) to convert in to solid, through various characterization techniques like self-emulsification, in vitro drug release profile and drug content estimation. The prepared L-SNEDDS converted into S-SNEDDS, SF1-SF6 by adsorption technique using Aerosil 200, Neusilin US2, and Neusilin UFL2 to improve flowability, compressibility and stability. Results: Formulation LF2 exhibited globule size of 82.4 nm, PDI 0.349 and Zeta potential -28.6 mV with drug indicating the stability and homogeneity of particles. The optimized formulation SF4 containing Neusilin UFL2 was characterized by DSC, FTIR, X-Ray diffraction studies and found no incompatibility and no major shifts were noticed. Formulation SF4 released 100 % drug in 20 min against pure drug release of 47 % in 60 min. Regardless of the form (i.e. liquid or solid) similar performance of emulsification efficiency is observed. Conclusion: The results demonstrated that the technique of novel solid self-nanoemulsifying drug delivery system can be employed to enhance the solubility and dissolution rate of poorly water-soluble drug budesonide.


2017 ◽  
Vol 9 (3) ◽  
pp. 55
Author(s):  
Manjunath P. N. ◽  
Satish C. S. ◽  
Vasanti S. ◽  
Preetham A. C. ◽  
Naidu Ras

Objective: The aim of this study was to formulate and evaluate gastro retentive drug delivery system (GRRDS) using an effervescent approach for simvastatin.Methods: Floating tablets were prepared using directly compressible polymers hydroxypropyl methylcellulose (HPMC) K100M, HPMC K4M and carboxymethylcellulose sodium (NaCMC). The prepared tablets were subjected to pre-formulation studies like Compressibility index, Hausner ratio and post compression parameters like buoyancy/floating test and In vitro dissolution study.Results: Drug-excipient compatibility studies performed with the help of FTIR instrument indicated that there were no interactions. The DSC thermogram of the formulations revealed that crystalline form of simvastatin existed in the formulation which was confirmed by X-ray powder diffraction. Dissolution studies indicated that there was a decrease in the drug release with an increase in the polymer viscosity. The tablets prepared with low-viscosity grade HPMC K4M exhibited short Buoyancy Lag Time and floated for a longer duration as compared with formulations containing high viscosity grade HPMC K100M. The ‘n’ value for dissolution studies for all the formulations was found to be in the range of 0.647 to 0.975 indicating non-Fickian or anomalous drug transport. Conclusion: The drug release rate and floating duration of tablets depended on the nature of the polymer and other added excipients. The release rate of the drug can be optimized by using different ratios of polymers and other excipients. The formulation F8 achieved the optimized batch and complied with all the properties of the tablets.


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