Studies on Protective Coating IX

Film Coating Theory and Practice

“…Stress-strain data may he used in comparing film samples as a function of formulation factors, e.g., polymer combinations used, plasticizer, solverit system or surfactant employed, the effect of dispersed solids; or thc data aftcr correlation to coat mechanical stability properties on a given substrate may provide a direct indication of coat friability resistance, impact strength, abrasion resistance, and other properties, Munden et al (45) and Utsumi (46) have recently rcported the modulus of elasticity, tensile strength, and per cent elongation of plasticized and unplasticizcd free films. Kabre (47) reports that the plasticizer is the most important formulation factor affecting mechanical properties of films, and he compared a series of plasticizcrs for their effect on the mechanical properties of a cellulosic polymer systcm.…”

Free Films I: Apparatus and Preliminary Evaluation

“…The screening and testing of polymers as potential film coatings were the subjects of a number of investigations (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17). In these studies, films were evaluated on the basis of their performance on film-coated tablets or as free unsupported films.…”

Effects of Solids-Loading on Moisture Permeability Coefficients of Free Films

“…Virtually nothing has been published that quantitatively indicates the effects of conspergents (dispersed nonpolymeric nonfilm-forming additives) upon the properties of pharmaceutical polymer films. Only very recently have pharmaceutical scientists begun to examine the structural, mechanical, and physiochemical properties of films related to film application, performance, and use (1,2). EXPERIMENTAL Materials-A hydroxypropyl methylcellulose' and a low molecular weight ethylcellulose* were the two polymers used.…”

“…The thickness of each film disk was measured in the center and around the periphery with a micrometers, reading to 1 X in., and the weighings were carried out on an analytical balance. All thickness and weight measurements were made after residual solvent had been removed from the samples by storing the films as previously described for 1 week.…”