Influence of hydrophilic character of plasticizer and polymer on certain film properties

Okor, R. S.

doi:10.1016/0378-5173(82)90172-7

Cited by 24 publications

(3 citation statements)

References 5 publications

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“…Other workers using plasticizers in the formulation of films have also reported greater drug release brought about by the water-soluble plasticizers. Such observations have been attributed to the gradual dissolution of the plasticizer into the dissolution medium, resulting in a more permeable matrix with a higher rate of drug release (Okor 1982). Another reason was the presence of less aggregated microspheres with a greater unit area for drug release.…”

Section: Resultsmentioning

confidence: 97%

Effects of poly(vinylpyrrolidone) and ethylcellulose on alginate microspheres prepared by emulsification

Chan

Heng

1998

Journal of Microencapsulation

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Calcium alginate microspheres were prepared by an emulsification process. The effects of two co-polymers, namely poly(vinylpyrrolidone) and ethylcellulose, on the properties of the microspheres were studied. Microspheres prepared with and without poly(vinylpyrrolidone) were spherical and discrete. The microspheres containing poly(vinylpyrrolidone) exhibited a better flow property but the drug content was lower and the drug release rate higher. The method of incorporating poly(vinylpyrrolidone) was found to (significantly) affect the size distribution and drug content of the microspheres. Ethylcellulose produced marked aggregation of the microspheres which also showed a lower drug content, but a slower drug release. The retardation in drug release was attributed to the formation of aggregated microspheres with a less permeable matrix. The addition of triethyl citrate, which is a water-soluble plasticizer, was found to increase the rate of drug release while the use of a higher viscosity grade of ethylcellulose produced the opposite effect. Ethylcellulose improved the flowability of the microspheres to a greater extent than poly(vinylpyrrolidone).

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Section: Resultsmentioning

confidence: 97%

Effects of poly(vinylpyrrolidone) and ethylcellulose on alginate microspheres prepared by emulsification

Chan

Heng

1998

Journal of Microencapsulation

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“…Hydrogel membranes plasticized with glycerol displayed increased percentage of swelling due to polymer glycerol linkage and the increased total hydrophilic nature. [ 31 ] The extent of swelling was lower in cross-linked hydrogel membranes due to the reduction in water absorption as the glutaraldehyde-treated hydrogel membranes absorbed less water than hydrogel membranes without glutaraldehyde (S 1 F 4 , S 1 F 8 , S 1 F 12 ) [ Table 3 ]. In addition, the extent of swelling was less profound in cross-linked hydrogel membranes due to decreased polymer chain mobility.…”

Section: Resultsmentioning

confidence: 99%

Preparation and characterization of gatifloxacin-loaded sodium alginate hydrogel membranes supplemented with hydroxypropyl methylcellulose and hydroxypropyl cellulose polymers for wound dressing

Prabu

Majdalawieh

Abu‐Yousef

et al. 2016

Int J Pharma Investig

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Introduction:The aim of this study is to evaluate gatifloxacin-loaded sodium alginate hydrogel membranes, supplemented with glycerol (a plasticizer), glutaraldehyde (a cross-linking agent), and hydroxypropyl methylcellulose (HPMC) or hydroxypropyl cellulose (HPC) polymers, as potential wound dressing materials based on their physicochemical properties and the sustain-release phenomenon.Materials and Methods:The physicochemical properties of the prepared hydrogel membranes were evaluated by several methods including Fourier transform infrared and differential scanning calorimetry. Different techniques were used to assess the swelling behavior, tensile strength and elongation, % moisture absorption, % moisture loss, water vapor transmission rate (WVTR), and microbial penetration for the hydrogel membranes. In vitro gatifloxacin release from the hydrogel membranes was examined using the United States Pharmacopeia XXIII dissolution apparatus. Four kinetics models (zero-order, first-order, Higuchi equation, and Korsmeyer-Peppas equation) were applied to study drug release kinetics.Results:The addition of glycerol, glutaraldehyde, HPMC, and HPC polymers resulted in a considerable increase in the tensile strength and flexibility/elasticity of the hydrogel membranes. WVTR results suggest that hydrated hydrogel membranes can facilitate water vapor transfer. None of the hydrogel membranes supported microbial growth. HPMC-treated and HPC-treated hydrogel membranes allow slow, but sustained, release of gatifloxacin for 48 h. Drug release kinetics revealed that both diffusion and dissolution play an important role in gatifloxacin release.Conclusions:Given their physicochemical properties and gatifloxacin release pattern, HPMC-treated and HPC-treated hydrogel membranes exhibit effective and sustained drug release. Furthermore, HPMC-treated and HPC-treated hydrogel membranes possess physiochemical properties that make them effective and safe wound dressing materials.

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“…Thus, one of the objectives of the present study was to investigate the distribution of the permeability coefficients among the single microcapsules of varying core sizes or weights. Since it is well known that the molecular structure of a polymer can influence film flexibility [5,6] and porosity [7,8] the influence of the nature of the coating material on the permeability characteristics of the applied films was also investigated.…”

Section: Solute Permeability Of Certain Polymericmentioning

confidence: 99%

Solute Permeability of Certain Polymeric Films Applied on Aspirin Crystals to Form Microcapsules

Eichie

Okor

Gröning

2006

Journal of Macromolecular Science, Part B

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A study was carried out to investigate the solute permeability of various polymer films applied on aspirin crystal to form microcapsules. The coating materials were an acrylate methacrylate (AMA), poly 3-hydroxybutyrate-hydroxyvalerate (Biopol w ) and poly (lactic-glycolic) acid (PLGA). Organic solutions of the polymers were applied on the aspirin crystals (core) by a spray coating technique in a Wurster column. The microcapsule surfaces were investigated using scanning electron microscopy (SEM), while permeability studies were carried out on single microcapsules serving as micro dialysis cells. The amount of drug (m) permeating through the applied films in time (t) was analysed on the basis of Fickian diffusion. The SEM revealed numerous surface pores of size range 2.4 to 24 mm for the AMA films, while the PLGA and Biopol films, on the other hand, exhibited very few surface pores of size range 2.2 to 18 mm. However, the AMA films were more spongy than the PLGA and Biopol. The AMA films displayed a retarded release while the PLGA or Biopol films displayed a burst release, attributable to the differences in the film's porous structure. The Permeability coefficient (P) depended on the core weight of the single microcapsules, decreasing with increase in core weight. Thus, for an ensemble of the microcapsules the permeability coefficients of the films of the component microcapsules will have a distribution of P values even though the coating material is the same. This finding is important in the simulation of drug release from coated multiparticulate systems.

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Influence of hydrophilic character of plasticizer and polymer on certain film properties

Cited by 24 publications

References 5 publications

Effects of poly(vinylpyrrolidone) and ethylcellulose on alginate microspheres prepared by emulsification

Effects of poly(vinylpyrrolidone) and ethylcellulose on alginate microspheres prepared by emulsification

Preparation and characterization of gatifloxacin-loaded sodium alginate hydrogel membranes supplemented with hydroxypropyl methylcellulose and hydroxypropyl cellulose polymers for wound dressing

Solute Permeability of Certain Polymeric Films Applied on Aspirin Crystals to Form Microcapsules

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