Abstract
The rate at which phenobarbital and phenobarbital sodium, suspended in liquid paraffin, are released to buffers pH=3.o, 7.4 and 10.0 has been studied. The release rate of phenobarbital depends on its solubility and hence on the pH, whereas the initial release rate of phenobarbital sodium is governed by sedimentation and hence is independent of the pH. However, when phenobarbital sodium is released to buffer pH=3.0, it crystallizes in the interfacial layer after an initial release time. The release process in the release apparatus used cannot be described by a theory based on forced convection [i.e. the(e)scrd-theory], but has to be regarded as a natural convection process.
Similar content being viewed by others
References
Crommelin, D.J.A., andC.J. De Blaey (1980a)Int. J. Pharm. 5, 305–316;Ibidem (1980b)6, 29–42.
Fokkens, J.G., and C.J.De Blaey (1982) In preparation.
Grijseels, H., D.J.A. Crommelin andC.J. De Blaey (1981)Pharm. Weekblad Sci. Ed. 3, 129–144.
Higuchi, W.I., E.L. Parrott, D.E. Wurster andT. Higuchi (1958)J. Am. Pharm. Assoc. Sci. Ed. 47, 376–383.
Higuchi, W.I., E. Nelson andJ.G. Wagner (1964)J. Pharm. Sci. 53, 333–335.
The Extra Pharmacopoeia (1973) 26th Edition. The Pharmaceutical Press, London, XXI.
Merck Index (1976) Ninth edition. Merck & Co. Inc., Rayway, NJ, USA, 939–940.
Mooney, K.G., M.A. Mintun, K.J. Himmelstein andV.J. Stella (1981)J. Pharm. Sci. 70, 13–32.
Nogami, H., T. Nagai andT. Yotsuyanagi (1969)Chem. Pharm. Bull. 17, 499–509.
Schoonen, A.J.M., F. Moolenaar andT. Huizinga (1979)Int. J. Pharm. 4, 141–152.
Schoonen, A.J.M., F. Moolenaar, K.A. Reuvers andT. Huizinga (1980)Int. J. Pharm. 7, 29–43.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Fokkens, J.G., De Blaey, C.J. Drug release from non-aqueous suspensions. Pharmaceutisch Weekblad Scientific Edition 4, 117–121 (1982). https://doi.org/10.1007/BF01959028
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01959028