scholarly journals Drug-Loaded Hydrogels for Intraocular Lenses with Prophylactic Action against Pseudophakic Cystoid Macular Edema

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 976
Author(s):  
Nadia Toffoletto ◽  
Madalena Salema-Oom ◽  
Soledad Anguiano Igea ◽  
Carmen Alvarez-Lorenzo ◽  
Benilde Saramago ◽  
...  
Keyword(s):  
Drug Release ◽  
Cataract Surgery ◽  
Macular Edema ◽  
Cystoid Macular Edema ◽  
Release Kinetics ◽  
Drug Loading ◽  
In Vitro Release ◽  
Intraocular Lenses ◽  
Therapeutic Drug ◽  
Drug Concentrations

Pseudophakic cystoid macular edema (PCME), caused by chronic inflammation, is the most common cause of visual impairment in the medium-term after cataract surgery. Therefore, the prophylactic topical administration of combined steroidal and non-steroidal anti-inflammatory drugs is commonly done. Drug-eluting intraocular lenses (IOLs) gained interest as an efficient way to overcome the compliance issues related to the use of ocular drops without the need for additional surgical steps. The incorporation of functional monomers and molecular imprinting were herein applied to design hydrogels suitable as IOLs and able to co-deliver steroidal (dexamethasone sodium phosphate) and non-steroidal (bromfenac sodium) drugs. The incorporation of N-(2-aminopropyl) methacrylamide (APMA) increased the drug uptake and improved the in vitro release kinetics. Imprinting with bromfenac resulted in a decreased drug release due to permanent drug bonding, while imprinting with dexamethasone increased the amount of dexamethasone released after dual-drug loading. The application of a mathematical model to predict the in vivo drug release behavior suggests the feasibility of achieving therapeutic drug concentrations of bromfenac and dexamethasone in the aqueous humor for about 2 and 8 weeks, respectively, which is compatible with the current topical prophylaxis after cataract surgery.

Local delivery of mitoxantrone for the treatment of malignant brain tumors in rats

2002 ◽  
Vol 97 (5) ◽  
pp. 1173-1178 ◽  
Author(s):  
Francesco DiMeco ◽  
Khan W. Li ◽  
Betty M. Tyler ◽  
Ariel S. Wolf ◽  
Henry Brem ◽  
...  
Keyword(s):  
Release Kinetics ◽  
Drug Loading ◽  
Malignant Gliomas ◽  
Therapeutic Drug ◽  
Content Type ◽  
Fischer 344 ◽  
Drug Concentrations ◽  
Brain Tumor Cell ◽  
Fine Print

Object. Mitoxantrone is a drug with potent in vitro activity against malignant brain tumor cell lines; however, its effectiveness as a systemic agent has been hampered by poor central nervous system penetration and dose-limiting myelosuppression. To avoid these problems, we incorporated mitoxantrone into biodegradable polymeric wafers to be used for intracranial implantation, a strategy that has been shown to be safe and successful in the treatment of malignant gliomas. The authors investigated the release kinetics, toxicity, distribution, and efficacy of mitoxantrone delivered from intracranially implanted biodegradable wafers in the treatment of 9L gliosarcoma in Fischer 344 rats. Methods. Mitoxantrone released from the biodegradable wafer matrix reached therapeutic drug concentrations in the brain for at least 35 days. Only animals with implanted wafers of the highest drug loading dose (20% mitoxantrone by weight) showed signs of significant toxicity. In three separate efficacy experiments, animals treated with mitoxantrone-loaded biodegradable wafers had significantly improved survival compared with control animals. The combined median survival for each treatment group was the following: 0% mitoxantrone wafers, 19 days; 1%, 30 days, p < 0.0001; 5%, 34 days, p < 0.0001; and 10%, 50 days, p < 0.0001. Conclusions. These findings establish that mitoxantrone delivered from intracranially implanted biodegradable wafers is effective in the treatment of malignant gliomas in rodents and should be considered for future clinical application in humans.

Mesoporous Silica Molecular Sieve based Nanocarriers: Transpiring Drug Dissolution Research

2017 ◽  
Vol 23 (3) ◽  
pp. 467-480 ◽  
Author(s):  
Satyanarayan Pattnaik ◽  
Kamla Pathak
Keyword(s):  
Drug Release ◽  
Mesoporous Silica ◽  
Molecular Sieves ◽  
Release Kinetics ◽  
Drug Loading ◽  
Scale Up ◽  
Water Soluble ◽  
Drug Dissolution ◽  
Water Soluble Drugs ◽  
Loading Methods

Background: Improvement of oral bioavailability through enhancement of dissolution for poorly soluble drugs has been a very promising approach. Recently, mesoporous silica based molecular sieves have demonstrated excellent properties to enhance the dissolution velocity of poorly water-soluble drugs. Description: Current research in this area is focused on investigating the factors influencing the drug release from these carriers, the kinetics of drug release and manufacturing approaches to scale-up production for commercial manufacture. Conclusion: This comprehensive review provides an overview of different methods adopted for synthesis of mesoporous materials, influence of processing factors on properties of these materials and drug loading methods. The drug release kinetics from mesoporous silica systems, the manufacturability and stability of these formulations are reviewed. Finally, the safety and biocompatibility issues related to these silica based materials are discussed.

Design, Synthesis and Studies on Novel Polymeric Prodrugs of Erlotinib for Colon Drug Delivery

2020 ◽  
Vol 20 ◽  
Author(s):  
Sahil Kumar ◽  
Bandna Sharma ◽  
Tilak R. Bhardwaj ◽  
Rajesh K. Singh
Keyword(s):  
Drug Delivery ◽  
Colon Cancer ◽  
Drug Release ◽  
Anticancer Agents ◽  
Release Kinetics ◽  
In Vitro Release ◽  
Specific Treatment ◽  
Drug Conjugates ◽  
Polymer Drug Conjugates

Aims: In the present study, polymer-drug conjugates were synthesized based on azo-bond cleavage drug delivery approach for targeting erlotinib as anticancer drug specifically to the colon for the proficient treatment of colon cancer. Background: Colon cancer (CC) is the third commonly detected tumor worldwide and it make up about 10 % of all cases of cancers. Most of the chemotherapeutic drugs available for treating colon cancer are not only toxic to cancerous cells but also to the normal healthy cells. Among the various approaches to get rid of the adverse effects of anticancer agents, prodrugs are one of the most imperative approaches. Objective: The objective of the study is to chemically modify the erlotinib drug through azo-bond linkage and suitable spacer which will be finally linked to polymeric backbone to give desired polymer linked prodrug. The azo reductase enzyme present in colon is supposed to cleave the azo-bond specifically and augment the drug release at the colon. Methods: The synthesized conjugates were characterized by IR and 1H-NMR spectroscopy. The cleavage of aromatic azobond resulted in a potential colon-specific liberation of drug from conjugate studied in rat fecal contents. In vitro release profiles of polyphosphazene-linked conjugates of erlotinib have been studied at pH 1.2, pH 6.8 and pH 7.4. The stability study was designed to exhibit that free drug was released proficiently and unmodified from polyphosphazene-erlotinib conjugates having aromatic azo-bond in artificial colon conditions. Results: The synthesized conjugates were demonstrated to be stable in simulated upper gastro-intestinal tract conditions. The drug release kinetics shows that all the polymer-drug conjugates of erlotinib follow zero-order release kinetics which indicates that the drug release from the polymeric backbone is independent of its concentration. Kinetic study of conjugates with slope (n) shows the anomalous type of release with an exponent (n) > 0.89 indicating a super case II type of release. Conclusion: These studies indicate that polyphosphazene linked drug conjugates of erlotinib could be the promising candidates for the site-specific treatment of colon cancer with least detrimental side-effects.

Effect of Intravitreal Injection as a Primary Treatment in Cystoid Macular Edema after Cataract Surgery

2012 ◽  
Vol 53 (3) ◽  
pp. 428 ◽  
Author(s):  
Joo Yeon Kim ◽  
Joung Mok Kim ◽  
Young Ju Lew ◽  
Chul Gu Kim ◽  
Sung Won Cho ◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Macular Edema ◽  
Intravitreal Injection ◽  
Cystoid Macular Edema ◽  
Primary Treatment

Preparation, evaluation, and in vitro release of chitosan-alginate tanshinone self-microemulsifying sustained-release microcapsules

2020 ◽  
pp. 1-9
Author(s):  
Yunhong Wang ◽  
Rong Hu ◽  
Yanlei Guo ◽  
Weihan Qin ◽  
Xiaomei Zhang ◽  
...  
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Release Rate ◽  
Orthogonal Design ◽  
Drug Loading ◽  
In Vitro Release ◽  
Core Material ◽  
Evaluation Indexes ◽  
Vitro Release

OBJECTIVE: In this study we explore the method to prepare tanshinone self-microemulsifying sustained-release microcapsules using tanshinone self-microemulsion as the core material, and chitosan and alginate as capsule materials. METHODS: The optimal preparation technology of chitosan-alginate tanshinone self-microemulsifying sustained-release microcapsules was determined by using the orthogonal design experiment and single-factor analysis. The drug loading and entrapment rate were used as evaluation indexes to assess the quality of the drug, and the in vitro release rate was used to evaluate the drug release performance. RESULTS: The best technology of chitosan-alginate tanshinone self-microemulsifying sustained-release microcapsules is as follows: the concentration of alginate is 1.5%, the ratio of tanshinone self-microemulsion volume to alginate volume to chitosan mass is 1:1:0.5 (ml: ml: g), and the best concentration of calcium chloride is 2.0%. To prepare the microcapsules using this technology, the drug loading will be 0.046%, the entrapment rate will be 80.23%, and the 24-hour in vitro cumulative release rate will be 97.4%. CONCLUSION: The release of the microcapsules conforms to the Higuchi equation and the first-order drug release model and has a good sustained-release performance.

Formulation and Evaluation of Transdermal patch of Methimazole

2021 ◽  
pp. 4667-4672
Author(s):  
Nani Tadhi ◽  
Himansu Chopra ◽  
Gyanendra Kumar Sharma
Keyword(s):  
Drug Release ◽  
Release Kinetics ◽  
In Vitro Release ◽  
Transdermal Patch ◽  
Formulation Development ◽  
In Vitro Drug Release ◽  
Drug Release Study ◽  
Percent Moisture ◽  
Release Study

Transdermal patch is a drug delivery device in which the drugs are incorporated and is design in such a way that it releases the drug in sustained and at predetermined rate to deliver the drug through the skin to the systemic circulation painlessly. The aim of this research study was to formulate a controlled and sustained release transdermal matrix type patch of Methimazole. The matrix patch was prepared by solvent casting method using a various polymer in different concentration, HPMC (hydrophilic), Eudragit RL100 and Ethyl cellulose (hydrophobic) polymer. Total 9 prototype formulation were prepared and it was subjected for various evaluation test; weight uniformity, Folding endurance, thickness, Drug content, percent moisture content, percent Moisture uptake and In-vitro drug release study using Franz diffusion cell. The in-vitro CDR% data was fit into kinetics model to see the release kinetics from the patches. The Formulation F5 was choosen as a best formulation according to in-vitro drug release study. The in-vitro release was found 81.12 % in 12 hours, it followed zero order kinetics. The nature of polymer and concentration ratio of polymers plays a crucial role for obtaining a good transdermal patch design; therefore optimisation is very important step to formulate a desired TDDS. Therefore the result of the study encourages a further study and is hopeful that the present study would contribute to the recent pharmaceutical research for formulation development.

Sign in / Sign up

Export Citation Format

Share Document