Application of intrinsic viscosity and interaction constant as a formulation tool for film coating. III. Mechanical studies on free ethyl cellulose films, cast from organic solvents

Arwidsson, Hans; Johansson, Björn

doi:10.1016/0378-5173(91)90347-q

Cited by 9 publications

(3 citation statements)

References 9 publications

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“…Even though data on the modulus of elasticity are in good agreement with data presented elsewhere, 18,19 it should be noted that the mechanical properties are highly dependent on the rate of testing, the temperature, humidity, size, and shape of specimen. Data presented in Figure 2 are, however, comparable within the group, because they were obtained from experiments using the same conditions.…”

Section: Resultssupporting

confidence: 57%

Effect of hydroxyl group content in ethyl cellulose on permeability in free films and coated membranes

Hjärtstam¹,

Hjertberg²

1999

J. Appl. Polym. Sci.

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ABSTRACT:The change in the water permeability, glass transition temperatures, and mechanical properties of ethyl cellulose with different degrees of substitution are presented. Studies of the hydroxyl group content on the polymer chains indicate that the mechanical properties of a free film decrease as the hydroxyl group content increases. This is thought to be due to the lower solubility of ethyl cellulose with a lower degree of substitution, as determined by the interaction constant in ethanol and the ability of the film with a high hydroxyl group content to hold more water. Furthermore, an increase in hydroxyl group content increases water permeability. Finally, a study of spray-coated pellets has been performed and reveals a similar effect. The higher the hydroxyl group content, the higher the release rate and, at the same time, the decrease in Vickers hardness.

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Section: Resultssupporting

confidence: 57%

Effect of hydroxyl group content in ethyl cellulose on permeability in free films and coated membranes

Hjärtstam¹,

Hjertberg²

1999

J. Appl. Polym. Sci.

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“…The resulting films were hard, brittle and did not disperse in water. It has been reported that the properties of films cast from organic solvents may change by varying the composition of solvent mixtures even though the composition of the dried films is the same [52-56]. Using this approach, we found, surprisingly, that addition of EtOH (final concentrations 50 to 65%) to the casting solvents ethyl acetate, CH 3 COOH and acetone, respectively, resulted in films with dramatically altered properties.…”

Section: Resultsmentioning

confidence: 78%

Water dispersible microbicidal cellulose acetate phthalate film

Neurath

Strick

2003

BMC Infect Dis

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Background: Cellulose acetate phthalate (CAP) has been used for several decades in the pharmaceutical industry for enteric film coating of oral tablets and capsules. Micronized CAP, available commercially as "Aquateric" and containing additional ingredients required for micronization, used for tablet coating from water dispersions, was shown to adsorb and inactivate the human immunodeficiency virus (HIV-1), herpesviruses (HSV) and other sexually transmitted disease (STD) pathogens. Earlier studies indicate that a gel formulation of micronized CAP has a potential as a topical microbicide for prevention of STDs including the acquired immunodeficiency syndrome (AIDS). The objective of endeavors described here was to develop a water dispersible CAP film amenable to inexpensive industrial mass production.

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“…9 Arwidsson et al 10 studied the mechanical properties on free EC films cast from organic solvents. They noted that if water was involved in the film-formation process, the film became porous and spongy, thereby reducing its mechanical strength.…”

Section: Introductionmentioning

confidence: 99%

Studies of the water permeability and mechanical properties of a film made of an Ethyl Cellulose-Ethanol-Water ternary mixture

Hjärtstam

Hjertberg

1999

J. Appl. Polym. Sci.

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ABSTRACT:A water permeability study of ethyl cellulose (EC) film made from an EC-ethanol-water ternary mixture is presented. EC films were prepared by pouring the solution onto a polycarbonate plate and by spraying. The results reveal that the permeability of water, estimated by diffusion experiments, increases as the amount of the nonsolvent increases in the liquid-liquid demixing process. In addition, a relative decrease in the evaporation rate of ethanol compared to that of water following an increase in casting temperature or a higher EC concentration produces a membrane with lower permeability. A mechanical evaluation of the films is also presented. Addition of water to the solvent leads to decreases in the modulus of elasticity, stress, and elongation, due to changes in the morphology of the film. The surface of the film was visualized by SEM photomicrography.

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Application of intrinsic viscosity and interaction constant as a formulation tool for film coating. III. Mechanical studies on free ethyl cellulose films, cast from organic solvents

Cited by 9 publications

References 9 publications

Effect of hydroxyl group content in ethyl cellulose on permeability in free films and coated membranes

Effect of hydroxyl group content in ethyl cellulose on permeability in free films and coated membranes

Water dispersible microbicidal cellulose acetate phthalate film

Studies of the water permeability and mechanical properties of a film made of an Ethyl Cellulose-Ethanol-Water ternary mixture

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