Abstract
To achieve constant drug release and to avoid the use of organic solvents, potassium chloride tablets were coated with aqueous latexes containing dispersed pore-formers with pH-dependent solubility characteristics. The pore-forming agent, dibasic calcium phosphate, was insoluble in the latex but soluble at low pH. Upon contact with simulated gastric fluids, it leached out rapidly to form a rate-controlling, microporous membrane. The release of potassium chloride was linear with time up to 75–80% drug released. It increased with increasing level of pore-former and decreasing membrane thickness but was independent of the degree of agitation and the pH of the dissolution medium after leaching of the pigments. Upon storage at different relative humidities, moisture uptake of the film coat and variations in the release profiles over time were minimal.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
REFERENCES
F. Theeuwes. Elementary osmotic pump. J. Pharm. Sci. 64(12):1987–1991 (1975).
G. Kallstränd and B. Ekman. Membrane-coated tablets: A system for the controlled release of drugs. J. Pharm. Sci. 72(7):772–775 (1983).
G. N. Zentner, G. S. Rork, and K. J. Himmelstein. Osmotic flow through controlled porosity films: An approach to delivery of water soluble compounds. J. Control. Release 2:217–229 (1985).
A. G. Hansson, A. Giardino, J. R. Cardinal, and W. Curatolo. Perforated coated tablets for controlled release of drugs at a constant rate. J. Pharm. Sci. 77(4):322–324 (1988).
W.-Y. Kuu and S. H. Yalkowsky. Multiple-hole approach to zero-order release. J. Pharm. Sci. 74(9):926–933 (1985).
J. W. McGinity (ed.). Aqueous Polymeric Coatings for Pharmaceutical Applications, Marcel Dekker, New York, 1989.
The American Society for Testing and Materials. Standard Test Methods for Phosphorus in Water (Designation D515-82, Method C), pp. 7–8.
H. Nyqvist. Saturated salt solutions for maintaining specified relative humidities. Int. J. Pharm. Tech. Prod. Mfr. 4(2):47–48 (1983).
American Pharmaceutical Association. Handbook of Pharmaceutical Excipients, Washington, D.C., 1986, pp. 30–33.
C. R. Steuernagel, Latex emulsions for controlled drug delivery. In J. W. McGinity (ed.), Aqueous Polymeric Coatings for Pharmaceutical Applications, Marcel Dekker, New York, 1989, pp. 1–61.
H. Kast. Aspects of film formation with emulsion copolymers. Macromol. Chem. Suppl. 10/11:447–461 (1985).
J. W. Vanderhoff. The transport of water through latex films. J. Polymer Sci. Symp. 41:155–174 (1973).
E. J. Schaller. Critical pigment volume concentration of emulsion based paints. J. Paint Technol. 40(525):433–438 (1968).
K. O. Lehmann, Chemistry and application properties of polymethacrylate coating systems. In J. W. McGinity (ed.), Aqueous Polymeric Coatings for Pharmaceutical Applications, Marcel Dekker, New York, 1989, pp. 153–245.
R. W. Baker and H. K. Lonsdale. Controlled release: Mechanisms and rates. In A. C. Tanquary and R. E. Lacey (eds.), Controlled Release of Biologically Active Agents, Plenum Press, New York, 1974, pp. 15–71.
F. Marson. Antifouling paints. II. A more detailed examination of the effect of pigment volume concentration. J. Appl. Chem. Biotechnol. 24:515–527 (1974).
F. Marson. Antifouling paints. I. Theoretical approach to leaching of soluble pigments from insoluble paint vehicles. J. Appl. Chem. Biotechnol. 19:93–99 (1969).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Bodmeier, R., Paeratakul, O. Constant Potassium Chloride Release from Microporous Membrane-Coated Tablets Prepared with Aqueous Colloidal Polymer Dispersions. Pharm Res 8, 355–359 (1991). https://doi.org/10.1023/A:1015897616351
Issue Date:
DOI: https://doi.org/10.1023/A:1015897616351