Relationship between drug dissolution and leaching of plasticizer for pellets coated with an aqueous Eudragit® S100:L100 dispersion

Bando, Hiroto; McGinity, James W.

doi:10.1016/j.ijpharm.2006.05.043

Cited by 25 publications

(8 citation statements)

References 11 publications

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“…The increasing concentration of plasticizers in coating solution generally shows decreased drug release profiles. 35,41) In the present study, similar results were obtained and presented in Fig. 6.…”

Section: Effect Of Coating Agents (Eudragit ® Rl/rs) and Coating Levesupporting

confidence: 90%

Preparation and Evaluation of Sustained-Release Doxazosin Mesylate Pellets

Kim

et al. 2013

CHEMICAL & PHARMACEUTICAL BULLETIN

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Doxazosin mesylate (DXM) sustained release pellets were prepared by an extrusion-spheronization and fluid-bed coating technique. The core pellets containing DXM were prepared by extrusion-spheronization technique, and coated by a fluid-bed coater to control the release of DXM. The factors affecting to properties of pellets, such as diluent content, type and coating level of coating agents and plasticizers were studied in the present study. Polymethacrylate derivatives (Eudragit ® RS PO and RL PO) were used for coating agents, and polyethylene glycol 6000 (PEG 6000), triethyl citrate (TEC) and castor oil were as plasticizers. To evaluate the properties of prepared pellets, the size of prepared pellets was investigated by sieve analysis technique and the morphology of pellets was evaluated by scanning electron microscopy. Through the dissolution test, factors that have an effect on the dissolution of the drug were evaluated. As the content ratio of microcrystalline cellulose (MCC) had increased, the dissolution was proportionally sustained. Eudragit ® RS PO had more marked sustaining effect on the dissolution rate than Eudragit ® RL PO, and the effect was more pronounced with the increased coating level. PEG 6000 was an appropriate plasticizer for DXM pellets, and increasing the content of PEG 6000, was also slightly decreasing the dissolution rate.Key words sustained release; pellet; extrusion-spheronization; fluid-bed coating; doxazosin mesylate Doxazosin mesylate (DXM) is a selective inhibitor of α 1 -adrenergic receptors and has been demonstrated to be effective for the treatment of hypertension and benign prostatic hyperplasia.1-3) DXM lowers the blood pressure of hypertensive patients by blocking postjunctional α 1 -adrenergic receptors, and then systemic vascular resistance decreases. 4)Taking a DXM can cause first-dose side effects like hypotension because of the rapid increase of drug concentration in the blood.5) Therefore the usual therapy of DXM is initially starting with a low dose (1 mg/d) and gradually increased up to the daily maximum recommended dose (16 mg/d).2) In order to overcome the adverse effects of DXM and to improve inconvenience of the regimen, various studies for controlled-release dosage forms of DXM have been conducted. [6][7][8] Application of the controlled release system to DXM could have benefits such as reducing the adverse effects by minimizing the fluctuation of drug concentration in the plasma. DXM could cause a significant reduction in blood pressure after administration of the first dose, so a formulation of sustained release of DXM could avoid this first dose effect. Among several systems for controlled release of the model drug, multi-unit dosage forms such as pellets or beads coated with polymers used as a release retardant has several advantages. The single unit dosage form like tablets has been widely used because of its simple and cost-effective manufacturing operations and ease of administration. 9,10) In comparison with a single unit dosage form, the multi-unit dosag...

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Section: Effect Of Coating Agents (Eudragit ® Rl/rs) and Coating Levesupporting

confidence: 90%

Preparation and Evaluation of Sustained-Release Doxazosin Mesylate Pellets

Kim

et al. 2013

CHEMICAL & PHARMACEUTICAL BULLETIN

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“…511 films (Table 4) showed the lowest dissolution values in both gastric and enteric media, probably due to the low proportion of pectin, which has high solubility and high liquid uptake ability (Guimarães et al, 2008;Maior et al, 2008). Dissolution properties were not affected by polymer concentration, but in simulated enteric medium, 511P film presented higher dissolution than 511 W (about 1.5 times), behavior that may be attributed to the hydrophilic nature of propylene glycol, which leads to increased mobility of the polymer chains (Bando & Mcginity, 2006). Besides, the hydrophilic plasticizers, when in contact with the dissolution medium, tend to be leached from polymeric films, decreasing their mechanical strength and facilitating pore formation, which are enhancers of the dissolution rate (Lecomte, Siepmann, Walther, Macrae, & Bodmeier, 2004).…”

Section: "In Vitro" Dissolution Of Free Filmsmentioning

confidence: 96%

Films from resistant starch-pectin dispersions intended for colonic drug delivery

Meneguin

Cury

Evangelista

2014

Carbohydrate Polymers

104

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Free films were obtained by the solvent casting method from retrograded starch-pectin dispersions at different polymer proportions and concentrations with and without plasticizer. Film forming dispersions were characterized according to their hardness, birefringence and rheological properties. The polymer dispersions showed a predominantly viscous behavior (G″>G') and the absence of plasticizers lead to building of stronger structures, while the occurrence of Maltese crosses in the retrograded dispersions indicates the occurrence of a crystalline organization. Analyses of the films included mechanical properties, thickness, superficial and cross sectional morphology, water vapor permeability, liquid uptake ability, X-ray diffractometry, in vitro dissolution and enzymatic digestion. The high resistant starch content (65.8-96.8%) assured the resistance of materials against enzymatic digestion by pancreatin. Changes in the X-ray diffraction patterns indicated a more organized and crystalline structure of free films in relation to isolated polymers. Increasing of pectin proportion and pH values favored the dissolution and liquid uptake of films. Films prepared with lower polymer concentration presented better barrier function (WVP and mechanical properties).

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“…The cumulative amounts of miglitol released from CR1, CR2 and CR3 formulations were greater than 33% although Eudragit L 100-55 polymer is insoluble at pH 1-2. This could be because, it has been reported that Eudragit films can form cavities at this pH due to leaching of the plasticizer from the polymer film (Bando and McGinity, 2006). The drug may have potentially been released through these cavities formed in the polymeric film.…”

Section: Discussionmentioning

confidence: 99%