Search results for "controlled release."

Quantitative analysis of the effect of controlled-release formulation on nonlinear gastrointestinal absorption of P-glycoprotein substrate talinolol …

2020

Abstract Oral absorption of talinolol, a substrate of P-glycoprotein (P-gp), from a sustained-release (SR) formulation was reportedly decreased compared to that from an immediate-release (IR) formulation. The aim of this study was to predict and understand the effect of controlled-release formulation on the oral absorption of P-gp substrates by developing a physiologically based pharmacokinetic (PBPK) absorption model incorporating multiple kinetic parameters obtained from in vitro studies, using talinolol as a model substrate. Simulation analysis using the developed PBPK absorption model indicated that the clinically observed marked decrease in the plasma concentration of talinolol adminis…

Effects of controlled-release on the pharmacokinetics and absorption characteristics of a compound undergoing intestinal efflux in humans

2006

Abstract Objective The number of active pharmaceutical ingredients (API) undergoing inhibitable and saturable intestinal efflux is considerable. As a consequence, absorption and bioavailability may depend on the intestinal concentration profile of the drug and may vary as a function of dose and release rate of the drug from the dosage form. The impact of controlled versus immediate-release on the absorption of P-glycoprotein substrates is currently unknown. Thus, the main focus of the present study was a comparison of the pharmacokinetics of the P-gp model substrate talinolol following administration of immediate-release (IR) and controlled-release (CR) tablets to healthy human volunteers w…

The adjunctive use of a controlled-release chlorhexidine chip following treatment with a new ultrasonic device in supportive periodontal therapy: a p…

2007

Abstract:  Objective:  The aim of this randomised, split-mouth, controlled clinical trial was to evaluate the effectiveness of a controlled-release chlorhexidine chip (CHX chip) as an adjunctive therapy to scaling and root planing (SRP) with a newly developed ultrasonic device in supportive periodontal therapy (SPT). Materials and methods:  Twenty patients with moderate-to-severe chronic periodontitis, displaying at least four sites with probing depth (PD) ≥5 mm and persistent bleeding on probing (BOP), were recruited for the study. The target sites were randomly treated with either a newly developed piezo-driven ultrasonic device VectorTM- or ultrasonic system (VUS) + CHX chip or VUS alone…

Selective adsorption of oppositely charged PNIPAAM on halloysite surfaces: a route to thermo-responsive nanocarriers.

2018

Halloysite nanotubes were functionalized with stimuli-responsive macromolecules to generate smart nanohybrids. Poly(N-isopropylacrylamide)-co-methacrylic acid (PNIPAAM-co-MA) was selectively adsorbed into halloysite lumen by exploiting electrostatic interactions. Amine-terminated PNIPAAM polymer was also investigated that selectively interacts with the outer surface of the nanotubes. The adsorption site has a profound effect on the thermodynamic behavior and therefore temperature responsive features of the hybrid material. The drug release kinetics was investigated by using diclofenac as a non-steroidal anti-inflammatory drug model. The release kinetics depends on the nanoarchitecture of th…

2021

The controlled release of antibiotics prevents the spread of pathogens and thereby improves healing processes in regenerative medicine. However, high concentrations may interfere with healing processes. It is therefore advantageous to use biodegradable materials for a controlled release. In particular, multilayer materials enable differential release at different surfaces. For this purpose, collagen sheets of different properties can be bonded by photochemical crosslinking. Here, we present the development and application of an easily accessible, additively manufactured sample holder to study the controlled release of vancomycin from modularly assembled collagen laminates in two directions.…

Nanosponges for the protection and release of the natural phenolic antioxidants quercetin, curcumin and phenethyl caffeate

2020

The inclusion of polyphenols into nanoporous materials may significantly improve their application as radical trapping agents for therapeutic purposes. In the present work, nanosponges based on hypercross- linked cyclodextrins and calixarenes (NS1–NS3) were used as carriers of three natural phenolic antioxidants: quercetin (Que), curcumin (Cur) and phenethyl caffeate (Phec). Good w/w loadings, namely 7.3% for the Que–NS1 composite, 17.3% for Cur–NS2 and 12.9% for Phec–NS3, were achieved. The release kinetics and the inhibition rate constants (kinh) of the reaction with alkylperoxyl radicals (ROO.) in 0.1 M phosphate buffer solutions at pH 7.4 were studied and indicated better antioxidant ac…

Algae and Their Extracts in Medical Treatment

2018

Scientific efforts undertaken in recent decades have undoubtedly proven that algae are an inestimable and, what is more, important renewable source of hundreds of chemical compounds characterized by a wide spectrum of biological activity. Polysaccharides, phenolic compounds and their derivatives, pigments, proteins, lipids, and fatty acids are the substances that can be isolated from seaweeds, possessing antimicrobial, antiviral, antifungal, antilipidemic, antitumor, antidiabetic, anticoagulant, antioxidant, and antiallergic properties, which can be successfully utilized for human needs. The majority of attention has been focused on marine polysaccharides and their application in medicine a…

Development of controlled release systems of biocides for the conservation of cultural heritage

2017

Abstract The presence of microorganisms is one of the main causes of monument deterioration. Biocides are usually applied after or before restoration in order to prevent or slow down microbial growth. Frequent applications are necessary leading to increased costs and high risks to humans and the environment. The aim of this study is the design of novel controlled release systems comprising a biocide loaded into a mesoporous silica. Pristine MCM41 as well as MCM41 functionalised with carboxy- (MCM41-COOH) and amino-groups (MCM41-NH2) were used. Biotin T and New Des 50, two commercial formulations, were chosen as biocides. The biocide encapsulation was performed adding the mesoporous silica t…

Antimicrobial beeswax coated polylactide films with silver control release capacity.

2013

Although the application of silver based antimicrobial systems is a widespread technology, its implementation in areas such as food packaging is still challenging. The present paper describes the fabrication of poly(lactic acid) (PLA) coated with beeswax with controlled release properties for sustained antimicrobial performance. Release of silver ions from the polymers was monitored voltammetrically under various conditions (surface contact, immersion in various liquid media and at different pH values) throughout at least 7days. A higher release was noted with decreasing pH while surface release was much slower than the release when immersed in liquid medium. While uncoated films demonstrat…

Formulation of Mesoporous Silica Nanoparticles for Controlled Release of Antimicrobials for Stone Preventive Conservation

2020

The biotic deterioration of artifacts of archaeological and artistic interest mostly relies on the action of microorganisms capable of thriving under the most disparate environmental conditions. Thus, to attenuate biodeterioration phenomena, biocides can be used by the restorers to prevent or slow down the microbial growth. However, several factors such as biocide half-life, its wash-out because of environmental conditions, and its limited time of action make necessary its application repeatedly, leading to negative economic implications. Sound and successful treatments are represented by controlled release systems (CRSs) based on porous materials. Here, we report on the design and developm…