Interactions of biopolymers carrageenans with cationic drug doxazosin mesylate characterized by means of differential scanning calorimetry.
When ionic polymers (polyelectrolytes) are used as excipients in pharmaceutical formulations, the properties of oppositely charged drugs may be strongly affected by the charge-charge interactions or complex formation. Usually these effects are considered as a negative event resulting in a drug-excipient incompatibility. Sometimes ionic interactions are preferred to prolong drug release from dosage forms in a controllable manner. Ionic interactions of carrageenans with doxazosin mesylate were confirmed by differential scanning calorimetry (DSC). Evident peak shifts and shape changes of assumed desulfation peak of carrageenans in concordance with disappearance of melting peak of doxazosin mesylate (DM) in DSC curves were obtained. The range of thermal effects is depended on the ratio of doxazosin mesylate and carrageenans. The higher the ratio of DM compared to CARRs the more evident are the interactions.
Pavli
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M
Faculty of Pharmacy, University of Ljubljana, Slovenia.
Vrecer
F
F
Baumgartner
S
S
D000317:Adrenergic alpha-Antagonists / Q000008:administration & dosage / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002351:Carrageenan / Q000737:chemistry*; D003692:Delayed-Action Preparations; D017292:Doxazosin / Q000008:administration & dosage / Q000737:chemistry*; D005079:Excipients; D013816:Thermodynamics
D000317:Adrenergic alpha-Antagonists; D003692:Delayed-Action Preparations; D005079:Excipients; D002351:Carrageenan; D017292:Doxazosin