Controlled release from polyurethane films: Drug release mechanisms

Abstract

In this study, polyurethane‐films loaded with diclofenac were used to analyze the drug release kinetics and mechanisms. For this purpose, the experimental procedures were developed under static and dynamic conditions with different initial drug loads of 10, 20, and 30%. In the dynamic condition, to better simulate the biological flow, drug release measurements were investigated at flow rates of 7.5 and 23.5 ml/s. These values indicate the flow rate of the internal carotid artery (ICA) for a normal state of a body and for a person during the exercise, respectively. The experimental data were analyzed and adjusted by Higuchi, Korsmeyer–Peppas, First‐order, zero‐order, and Peppas–Sahlin models in order to understand the mechanisms contributed. Finally, drug release mechanisms were specified by investigating the model correlation coefficients. Experimental results showed that increasing the flow rate and initial drug loads enhance drug liberation. In addition, the rate of release is more influenced by the drug dosage in the static state. The analysis revealed that diffusion, burst, and osmotic pressure are the principal mechanisms contributed. Moreover, Fickian type was the dominant mechanism at all duration of release. However, it was discovered using Peppas–Sahlin model that the contribution of the diffusion mechanism decreases with increasing flow rate and initial dosage. Furthermore, the tests at different drug dosages showed that the number of stages in medication release profile is independent of the flow rate and the medicine percentage. One can conclude that the drug release kinetic in static state is more influenced by drug dosage compared with dynamic state.

Viscoelastic Behavior of Drug-Loaded Polyurethane

“…Figure 2 shows the drug release from the polyurethane samples at the static and continuous flow, with 10 and 20% of drug loading. The release profile for each case consists of two stages, respectively, burst release and extended release [ 30 ].…”

Investigation of the Release Mechanism and Mould Resistance of Citral-Loaded Bamboo Strips

“…The release mechanism model of P/Cn can reveal the relationship between the release kinetics and the release architecture variables in essence [ 23 ]. Consequently, the release curves of P/Cn8 at 25 °C and 36 °C were plotted.…”

“…When the carrier comes into contact with the water medium, various phenomena such as degradation, dissolution, and swelling can occur [ 22 ]. Under the action of diffusion, convection, explosion, ion exchange, osmotic pressure, and other mechanisms, different release curves are produced [ 23 ]. In addition, the release parameters are related to the properties of fungicides, such as the solubility, particle size, and hydrophilicity [ 15 ].…”

Development of a Model Based on Physical Mechanisms for the Explanation of Drug Release: Application to Diclofenac Release from Polyurethane Films

“…In this study, we used the experimental results of diclofenac epolamine (DE) release. DE is an anti-inflammatory and a model of the hydrophilic drug (water solubility of 5.55 mg/mL [ 42 ]), used in this regard, from the non-degradable polyurethane samples. The samples were prepared with the synthesis of hardener consisting of isocyanate type 4,4-diphenylmethylene diisocyanate (MDI) and resin composed of polyol, dye, and catalyst.…”