In vitro dissolution of pH sensitive microparticles for colon-specific drug delivery.
OBJECTIVE
The objective of this work is to prepare oral dosage systems based on enteric materials in order to verify their possible use as Colon-Specific Drug Delivery Systems (CSDDSs).


METHODS
In particular, three different copolymers of methyl-methacrylate (MMA) - acrylic acid (AA) are synthesized with increasing percentage of MMA (from 70% to 73%) and they are used to produce microparticles by the double-emulsion solvent evaporation method. The microparticles, loaded using theophylline as model drug, are then tested for drug release under varying pH to reproduce what happens in the human GI tract.


RESULTS
All the investigated systems have shown an effective pH sensitiveness: they show a good gastro-resistance, releasing the model drug only at higher pH, small intestine or colon, depending on the kind of used copolymer.


CONCLUSIONS
The results confirm the usefulness of both the materials and the methods proposed in this study for colon-specific delivery applications.
Dipartimento di Scienze Farmaceutiche e Biomediche, Università degli Studi di Salerno, Fisciano, Italy.
Anna Angela
AA
Barba
Annalisa
A
Dalmoro
Matteo
M
d'Amore
Gaetano
G
Lamberti
D000179:Acrylates / Q000008:administration & dosage / Q000737:chemistry; D003106:Colon / Q000187:drug effects* / Q000378:metabolism*; D016503:Drug Delivery Systems / Q000379:methods*; D004655:Emulsions / Q000008:administration & dosage / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008863:Microspheres; D019904:Polymethyl Methacrylate / Q000008:administration & dosage / Q000737:chemistry; D012995:Solubility; D012997:Solvents / Q000737:chemistry; D013806:Theophylline / Q000008:administration & dosage* / Q000737:chemistry*
D000179:Acrylates; D004655:Emulsions; D012997:Solvents; D019904:Polymethyl Methacrylate; D013806:Theophylline; C036658:acrylic acid