Microorganism-based monodisperse microcapsules: encapsulation of the fungicide tebuconazole and its controlled release properties

RSC Advances ◽  
2015 ◽  
Vol 5 (32) ◽  
pp. 25164-25170 ◽  
Author(s):  
Bo Zhang ◽  
Teng Zhang ◽  
Quanxi Wang ◽  
Tianrui Ren
Keyword(s):  
Controlled Release ◽  
Powdery Mildew ◽  
Drug Release ◽  
Release Rate ◽  
Drug Release Rate ◽  
Burst Effect ◽  
Initial Burst ◽  
Release System ◽  
Controlled Release System ◽  
Monodisperse Microcapsules

A controlled release system was prepared, it based on UF modified PCC cells in which TEB are loaded into cells. It can control the drug release rate, depress the initial “burst effect”, and was efficacious in controlling wheat powdery mildew.

The effect of molecular structure on the anticancer drug release rate from prodrug nanoparticles

2015 ◽  
Vol 51 (64) ◽  
pp. 12835-12838 ◽  
Author(s):  
Yoshikazu Ikuta ◽  
Yoshitaka Koseki ◽  
Tsunenobu Onodera ◽  
Hidetoshi Oikawa ◽  
Hitoshi Kasai
Keyword(s):  
Molecular Structure ◽  
Controlled Release ◽  
Drug Release ◽  
Anticancer Drug ◽  
Release Rate ◽  
Chemical Structure ◽  
Anticancer Agent ◽  
Drug Release Rate ◽  
Drug Nanoparticles

The controlled release of an anticancer agent from drug nanoparticles could be successfully achieved by optimizing the chemical structure of dimeric compounds as prodrug.

Preparation of Liquid Oral Mucoadhesive Gastro-retentive System of Nimodipine

2019 ◽  
Vol 16 (9) ◽  
pp. 862-871 ◽  
Author(s):  
Mai Mamdouh ◽  
Ahmed Donia ◽  
Ebtessam Essa ◽  
Gamal El Maghraby
Keyword(s):  
Critical Care ◽  
Controlled Release ◽  
Drug Release ◽  
Release Rate ◽  
Poloxamer 407 ◽  
Liquid Form ◽  
Drug Release Rate ◽  
Alginate Concentration ◽  
Gastro Retentive

Background: Nimodipine is a calcium channel blocker frequently used in critical care settings. It is mainly absorbed in the upper gastrointestinal tract. Accordingly, the development of gastroretentive formulation will be beneficial. The benefit would be maximized for critical care patients if the developed system was in liquid form to facilitate the administration through nasogastric tubing. Objective: Development of gastro-retentive liquid oral controlled release formulation of nimodipine through in situ gellation. Methods: Nimodipine dissolution was improved by solid dispersion (SD) using poloxamer 407. Sodium alginate solutions (1, 1.5 and 2%w/v) were loaded with the optimized SD microparticles. Carboxymethylcellulose was added to modulate the release and to augment mucoadhesion power. All in situ gelling alginate solutions were characterized regarding viscosity, gelling capacity and drug release. SD microparticles showed considerable improvement in nimodipine dissolution. Results: All alginate systems were pourable. Increasing alginate concentration increased the gelling capacity and reduced drug release rate. The addition of carboxymethylcellulose produced greater control over drug release rate. X-ray radiography showed successful stomach-retention over 8 hours in rabbits, which correlates with the controlled release pattern of the developed systems. Conclusion: The study provides the formulator with a range of gastroretentive controlled release formulations of nimodipine while maintaining the convenience of administration through nasogastric tubing with the potential for enhanced bioavailability.

Lipid-Based Implants: Impact of Formulation Parameters

2014 ◽  
Vol 1060 ◽  
pp. 87-90
Author(s):  
Marisa Nicolai ◽  
Vanessa Amaral ◽  
Cátia Antunes ◽  
Duangratana Shuwisitkul ◽  
Joana Portugal Mota
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Release Rate ◽  
Release Rates ◽  
Drug Release Rate ◽  
Blend Ratio ◽  
Drug Type ◽  
Formulation Parameters ◽  
Blend Ratios ◽  
Aqueous Solubilities

Lipid implants have been attracting attention in recent years. However, to better understand these systems, more fundamental studies are required. The objective of this work was to evaluate the effect of some formulation parameters, namely lipid and drug type, implant shape/surface area and lipid blend ratio, on drug release rate. The developed implants were cylindrical or spherical in shape with an even surface. Caffeine release from glycerol-trimyristate implant was very fast when compared with glycerol-tristerate matrix. The latter allowed a 4 month controlled release in contrast with glycerol-trimyristate matrix (~ 5 days). Caffeine and theophylline presented similar release rates, despite their different aqueous solubilities. In addition, different lipid blend ratios provided different release profiles for caffeine.

scholarly journals Drug release rate in vitro and bioavailability of new controlled release suspension of spherical matrix of ibuprofen.

1989 ◽  
Vol 4 (2) ◽  
pp. 100-104
Author(s):  
Yoshiaki Kawashima ◽  
Taro Iwamoto ◽  
Toshiyuki Niwa ◽  
Hirofumi Takeuchi ◽  
Tomoaki Hino ◽  
...  
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Release Rate ◽  
Drug Release Rate

scholarly journals Polymer Distribution and Mechanism Conversion in Multiple Media of Phase-Separated Controlled-Release Film-Coating

Pharmaceutics ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 80 ◽  
Author(s):  
Lu Chen ◽  
Guobao Yang ◽  
Xiaoyang Chu ◽  
Chunhong Gao ◽  
Yuli Wang ◽  
...  
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Release Rate ◽  
Water Soluble ◽  
Drug Dissolution ◽  
Acetate Buffer ◽  
Drug Solubility ◽  
Drug Release Rate ◽  
The Media ◽  
Multiple Media

Phase-separated films of water-insoluble ethyl cellulose (EC) and water-soluble hydroxypropyl cellulose (HPC) can be utilized to tailor drug release from coated pellets. In the present study, the effects of HPC levels and the pH, type, ionic strength and osmolarity of the media on the release profiles of soluble metoprolol succinates from the EC/HPC-coated pellets were investigated, and the differences in drug-release kinetics in multiple media were further elucidated through the HPC leaching and swelling kinetics of the pellets, morphology (SEM) and water uptake of the free films and the interaction between the coating polymers and the media compositions. Interestingly, the drug release rate from the pellets in different media was not in agreement with the drug solubility which have a positive correlation with the drug dissolution rate based on Noyes–Whitney equation law. In particular, the drug release rate in acetate buffer at pH 4.5 was faster than that in other media despite the solubility of drug was relatively lower, regardless of the HPC levels. It may be attributed to the mutual effect between the EC and acetate buffer, which improved the permeability of the film. In contrast, the release of drug in HCl solution was dependent on the HPC levels. Increasing the levels of HPC increased the effects of hydrogen ions on the polymer of HPC, which resulted in a lower viscosity and strength of the gel, forming the larger size of pores in polymer films, thus increasing the drug diffused from the coating film. Further findings in phosphate buffer showed a reduction in the drug release compared to that in other media, which was only sensitive to the osmolarity rather than the HPC level and pH of the buffer. Additionally, a mathematical theory was used to better explain and understand the experimentally measured different drug release patterns. In summary, the study revealed that the effects of the media overcompensated that of the drug solubility to some extent for controlled-release of the coating polymers, and the drug release mechanism in multiple media depend on EC and HPC rather than on HPC alone, which may have a potential to facilitate the optimization of ideally film-coated formulations.

scholarly journals Development and Optimization of Controlled Release Formulation and Process of Levetiracetam with Hot Melt Coating Technology

2021 ◽  
pp. 80-102
Author(s):  
Nilam Patel ◽  
Rupal Jani
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Release Rate ◽  
Water Soluble ◽  
Coating Process ◽  
Drug Release Rate ◽  
Release Formulation ◽  
Coating Technology ◽  
Controlled Release Formulation ◽  
Hot Melt

Conventional coating processes are based on aqueous or organic solvent system, resulting in the lengthy and tedious processes where use and removal of solvents consumes lots of energy and resources. Also, solvent disposal is a critical issue considering environmental hazard.Hot melt coating process avoids use of solvent and is short and energy-efficient process. Here, Hot-melt coating process (HMCP) is being developed to formulate lipid based oral controlled release formulation system to deliver highly water soluble Biopharmaceutical Classification System (BCS) class-I drug Levetiracetam. Pellets containing Active ingredient in the core portion were prepared by extrusion spheronization process with use of appropriate filler and binder. These core pellets were then coated using hot-melt coating technology with different levels of lipid and a hydrophilic component. Formulation and Process parameters were optimized to achieve targeted drug release profile and other target product profile with particular focus onHMCP. Quality by design (QbD) with DOE approach was used for designing and development of the formulation, by putting risk assessment Failure Mode and Effect analysis (FMEA, Fish-bone diagram), screening (by Plackett Burman), and optimization by Central Composite Design (CCC) studies. Appropriate ‘design space’ was proposed based on the optimization studies. The results demonstrated that the level of Low melting coating component and a hydrophilic component influenced the drug release rate from the formulation, and the rate of release could be optimized by varying the amount of these components in the formulation. Processing parameters like Temperature of the coating solution and atomization air, Atomization air pressure and Spray rate also affects the drug release rate and other parameters like coating efficiency and mean particle size. For optimized formulation, dissolution data model fitting was also carried out which adequately fits to Higuchi model suggesting that the drug release occurred predominantly by diffusion.

scholarly journals Hot Melt Coating: Development and Optimization of Controlled Release Formulation and Process of Oxcarbazepine

2021 ◽  
pp. 30-51
Author(s):  
Nilam Patel ◽  
Rupal Jani
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Release Rate ◽  
Model Fitting ◽  
Processing Parameters ◽  
Drug Release Profile ◽  
Drug Release Rate ◽  
Release Formulation ◽  
Controlled Release Formulation ◽  
Hot Melt

Hot-melt coating process (HMCP) is being developed to formulate lipid based oral controlled release formulation system for anti-epileptic drug Oxcarbazepine. Pellets containing Active ingredient in the core portion were prepared by extrusion spheronization process with use of appropriate filler and binder. These core pellets were then coated using hot-melt coating technology with different levels of solid lipid material and a hydrophilic component. Formulation and Process parameters were optimized to achieve targeted drug release profile and other target product profile with particular focus on HMCP. Quality by design (QbD) with DOE approach was used for designing and development of the formulation, by putting risk assessment (FMEA, Fish-bone diagram), screening (by Plackett Burman), and optimization (by CCC) studies. Appropriate ‘design space’ was proposed based on the optimization studies. The results demonstrated that the level of Low melting coating component and a hydrophilic component influenced the drug release rate from the formulation, and the rate of release could be optimized by varying the amount of these components in the formulation. Processing parameters like Temperature of the coating solution and atomization air, Atomization air pressure and Spray rate also affects the drug release rate and other parameters like coating efficiency and mean particle size. For optimized formulation, dissolution data model fitting was also carried out which adequately fits to Higuchi model suggesting that the drug release occurred predominantly by diffusion.

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