Development and In Vitro Evaluation of Polymeric Responsive Release Matrix Type Transdermal Patches of Two Anti-asthmatic Drugs

Abstract

Ketotifen fumarate, a mast cell stabilizer, and salbutamol sulfate, a bronchodilator, are frequently prescribed together for chronic asthma. This study aimed to combine both anti-asthmatic drugs in single polymeric responsive matrix type transdermal patches. Drug release from polymeric device was optimized by varying ratios of hydrophilic (polyvinyl pyrrolidone) and hydrophobic (ethyl cellulose) polymers. Propylene glycol was used as plasticizer and solvent system including mixture of chloroform and methanol. Physicochemical evaluations like thickness, weight variation, folding endurance, tensile strength, content uniformity and % moisture absorbance of developed patches were carried out. Developed patches were also subjected for in vitro release of drugs, and formulation of P6 with equal proportion of polyvinyl pyrrolidone and ethyl cellulose found optimized formulation with respect to release rate of both drugs. 76.49% of ketotifen fumarate and 77.49% of salbutamol sulfate were released from P6, and release of both drugs sustained up to 24 h. In the next step, permeability enhancers like Tween 20, isopropyl myristate, eucalyptus oil and span 20 were added to the formulation P6 and subjected to in vitro permeation study on Franz diffusion cell using rabbit skin. Results of in vitro permeation study revealed that transdermal patches with permeation enhancers permeate the significant amount of drugs in comparison with the formulation without enhancer.