Polymer particle erosion controlling drug release. II. Swelling investigations to clarify the release mechanism

Zuleger, Susanne; Fassihi, Reza; Lippold, B.

doi:10.1016/s0378-5173(02)00362-9

Cited by 46 publications

(18 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The axial expansion could be again the result of discharge and relaxation of tablet compression forces imposed during tabletting and is in agreement with earlier studies, 13,22 even though some different findings were reported elsewhere.…”

Section: Core Changessupporting

confidence: 92%

An investigation into the swelling properties, dimensional changes, and gel layer evolution in chitosan tablets undergoing hydration

Efentakis

Stamoylis

2009

Adv Polym Technol

View full text Add to dashboard Cite

ABSTRACT:The purpose of this research is to determine several characteristics of chitosan lactate in tablet form such as dimensional changes, gel evolution, swelling (liquid uptake), and erosion using an image analysis method. The examination of these characteristics will be helpful in the design of oral drug delivery systems with this polymer. It has been demonstrated that image analysis is a valuable technique, allowing the study of quantitative measurements of dimensional and core changes and gel evolution. The dimensional expansion changes of the chitosan lactate tablets were greater in water, and the crushing strength and the stirring effect affected these attributes to a limited extent. The fastest and greatest liquid uptake was observed in water, whereas the greatest erosion was observed in HCl. The thickness of the gel layer increased considerably with time up to the eighth hour, indicating the formation and development of a thick and durable gel, particularly in water. This is an essential characteristic for potential sustained drug release delivery. Consequently, this polymer appears to be a versatile material and a promising vehicle for the

show abstract

Section: Core Changessupporting

confidence: 92%

An investigation into the swelling properties, dimensional changes, and gel layer evolution in chitosan tablets undergoing hydration

Efentakis

Stamoylis

2009

Adv Polym Technol

View full text Add to dashboard Cite

show abstract

“…The calculations were carried out in Excel. Several simplifying assumptions were made and used the calculations: constant BHT concentration in pipe material, constant temperature of 33 o C, measurements commenced after 14 hours into the experiment, which was the time required for the temperature to stabilise at 33 o C, constant flow velocity of 1m/s, time step equalled time required for one circulation cycle of water in the system (150 s), diffusive layer thickness derived from literature and equal to 100μm [23,24]. Calculations were conducted with the method of successive approximations, adjusting the diffusion coefficient values.…”

Section: Determination Of Diffusion Coefficient Value For Bhtmentioning

confidence: 99%

Modelling the concentration of antioxidant BHT migrating from polyethylene pipe to water

Widomski¹,

Kowalska²,

Kowalski³

et al. 2012

WIT Transactions on the Built Environment

View full text Add to dashboard Cite

This paper covers laboratory and modelling studies of antioxidant BHT (butylated hydroxytoluene) migration from HDPE pipe used in water supply systems. Our laboratory experiments were conducted on a measuring stand constructed on a new HDPE pipe. Determination of BHT concentration in pipe samples was performed with high-resolution size-exclusion chromatography (HR-SEC). Concentration of BHT migrating to drinking water in laboratory conditions was determined with a Trace-Ultra/Polaris Q (Thermo USA) GC-MS system. Modelling studies concerning BHT concentration in water body were performed using commercial CDF software Fluent, Ansys Inc. Our calculations were based on experimentally determined input data, such as diffusion coefficient, as well as initial and boundary conditions. The obtained modelling results showed good agreement with the experimental data

show abstract

“…In addition, an increase of mass transfer rate and a decrease of film thickness as the increment of basket rotation speed has been reported (9). Although the erosion based on the low viscosity grade of the material was strongly influenced by agitation, the polymer particle erosion was only moderately affected by the hydrodynamic stress (14). Owing to the coating by layering both sides with strong gelling layer containing HPMC, the influence of hydrodynamic force on drug dissolution from the three-layer tablet was minimized.…”

Section: In Vitro Drug Release From the Prepared Tabletsmentioning

confidence: 95%

Variables Influencing Drug Release from Layered Matrix System Comprising Hydroxypropyl Methylcellulose

Phaechamud

2008

AAPS PharmSciTech

View full text Add to dashboard Cite

Abstract. The purpose of this study was to prepare and evaluate layered matrix tablets of propranolol HCl containing HPMC and phytowax as matrix component using direct compression technique. Layering with this polymeric matrix could prolong the release of drug and shift the release pattern approach to zero order as described from the least square curve fitting. Increasing the amount of coating layer could apparently prolong the drug release. The longer lag time of drug release from one planar apparently when the amount of coating layer was increased. HPMC concentration and compression force did not affect the drug release from this three-layer tablet. The drug release from this three-layer tablet was influenced by hydrodynamic force. An increase in stirring rate was a corresponding increasing in the release rate. From photoimage and SEM, gel mass of HPMC was increased with time during dissolution and covered the core surface, therefore dissolved drug molecules were allowed to diffuse out from the core through the polymer network of gel layer containing the porous structure. This suggested that HPMC and phytowax could be fabricated into the layered matrix tablet exhibiting sustained drug release.

show abstract

Polymer particle erosion controlling drug release. II. Swelling investigations to clarify the release mechanism

Cited by 46 publications

References 25 publications

An investigation into the swelling properties, dimensional changes, and gel layer evolution in chitosan tablets undergoing hydration

An investigation into the swelling properties, dimensional changes, and gel layer evolution in chitosan tablets undergoing hydration

Modelling the concentration of antioxidant BHT migrating from polyethylene pipe to water

Variables Influencing Drug Release from Layered Matrix System Comprising Hydroxypropyl Methylcellulose

Contact Info

Product

Resources

About