The influence of polymeric subcoats and pellet formulation on the release of chlorpheniramine maleate from enteric coated pellets.
The influences of aqueous polymeric subcoats and pellet composition on the release properties of a highly water-soluble drug, chlorpheniramine maleate (CPM), from enteric coated pellets were investigated. Three different aqueous polymeric subcoats, Eudragit RD 100, Eudragit RS 30D, and Opadry AMB, were applied to 10% w/w CPM-loaded pellets that were then enteric coated with Eudragit L 30D-55. Observed drug release from the coated pellets in acidic media correlated with water vapor transmission rates derived for the subcoat films. The influence of pellet composition on retarding the release of CPM from enteric coated pellets in 0.1 N HCl was investigated. The rate of drug release was greatest for pellets prepared with lactose, microcrystalline cellulose, or dibasic calcium phosphate compared with pellets formulated with citric acid and microcrystalline cellulose. Citric acid reduced the pellet micro-environmental pH, decreasing the amount of drug leakage in 0.1 N HCL during the first 2 hr of dissolution. Polymer flocculation was observed when CPM was added to the Eudragit L 30D-55 dispersion. An adsorption isotherm was generated for mixtures of CPM and the polymer and the data were found to fit the Freundlich model for adsorption. Adsorption of CPM to the polymer decreased with the addition of citric acid to the drug-polymer mixtures.
Division of Pharmaceutics, College of Pharmacy, The University of Texas at Austin, Austin, Texas, USA. diane.bruce@quintiles.com
L Diane
LD
Bruce
John J
JJ
Koleng
James W
JW
McGinity
D000180:Acrylic Resins / Q000737:chemistry; D000327:Adsorption; D002744:Chlorpheniramine / Q000008:administration & dosage / Q000737:chemistry*; D005583:Fourier Analysis; D006634:Histamine H1 Antagonists / Q000008:administration & dosage / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008689:Methacrylates / Q000737:chemistry; D010968:Plasticizers; D011108:Polymers / Q000737:chemistry; D011142:Polyvinyl Alcohol / Q000737:chemistry; D016062:Porosity; D012995:Solubility; D013608:Tablets, Enteric-Coated / Q000737:chemistry; D013678:Technology, Pharmaceutical; D014961:X-Ray Diffraction
D000180:Acrylic Resins; C477852:Eudragit L 30 D-55; D006634:Histamine H1 Antagonists; D008689:Methacrylates; D010968:Plasticizers; D011108:Polymers; D013608:Tablets, Enteric-Coated; C050528:Eudragit RS; D002744:Chlorpheniramine; D011142:Polyvinyl Alcohol