title: Evaluation of carboxymethyl guar films for the formulation of transdermal therapeutic systems.
abstract: Carboxymethyl guar (CMGS), an anionic semisynthetic guar gum derivative was evaluated for its suitability of use in transdermal drug-delivery systems. Terbutaline sulfate (TS) was used as a model drug. The diffusion of terbutaline sulfate from CMGS solution was relatively slower at pH 5 than at pH 10. It is most likely that the interaction between CMGS and terbutaline sulfate at pH 5 is physical, involving static interaction. The ability of such interactions in modifying the release kinetics of drug from the CMGS transdermal films was studied. The release was exponential from pH 5 formulations whereas the release rate followed zero or Higuchian order from pH 10 formulations. However, the diffusion kinetics of both pH 5 and pH 10 formulations followed zero order across human cadaver epidermis. Such an interaction was also found to alter the pharmacokinetic parameters of the drug. The steady-state concentration of TS was relatively consistent and the bioavailability was approximately 50% higher in pH 5 formulations than pH 10. The elimination rate constant/half-life was significantly different between pH 5 and pH 10 formulations.
authors.affiliation: Al-Ameen College of Pharmacy, Hosur road, Bangalore 560 027, Karnataka, India. snarasimha.murthy@roswellpark.org
authors.forename: S
authors.initials: S
authors.lastname: Narasimha Murthy
authors.forename: Shobha Rani R
authors.initials: SR
authors.lastname: Hiremath
authors.forename: K L K
authors.initials: KL
authors.lastname: Paranjothy
mesh_terms: D000277:Adjuvants, Pharmaceutic / Q000737:chemistry*; D000279:Administration, Cutaneous; D000328:Adult; D000818:Animals; D016503:Drug Delivery Systems; D005260:Female; D005685:Galactans / Q000737:chemistry*; D006207:Half-Life; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008297:Male; D008351:Mannans / Q000737:chemistry*; D053149:Plant Gums; D011817:Rabbits; D013696:Temperature; D013718:Tensile Strength; D013726:Terbutaline / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D014867:Water / Q000737:chemistry
chemical_list: D000277:Adjuvants, Pharmaceutic; D005685:Galactans; D008351:Mannans; D053149:Plant Gums; C469704:carboxymethyl guar gum; D014867:Water; D013726:Terbutaline