DESIGN, DEVELOPMENT AND EVALUATION OF MUCOADHESIVE PATCHES OF LOSARTAN FOR BUCCAL DELIVERY
Navpreet Kaur*, Nirmala, S.L Harikumar
ABSTRACT The buccal region offers an attractive route of administration for systemic drug delivery. Losartan is an angiotensin II receptor antagonist readily absorbed from the GIT, following oral administration. It has low bioavailability as it undergoes extensive first pass metabolism and low elimination half life. The present study was aimed at studying controlled release behavior of the drug using hydrophilic and hydrophobic polymers. The mucoadhesive polymers used in the formulation were ethylcellulose (hydrophobic), hydroxypropyl methyl cellulose and polyvinyl pyrrolidone (hydrophilic). These polymers were used to evaluate the effect of hydrophilic and hydrophobic polymers on the release pattern of the drug. Various mucoadhesive buccal films were prepared by employing EC alone, HPMC alone, PVP alone and in combination of all polymers in different ratios by solvent casting method using ethanol, and water as solvents, propylene glycol as plasticizer. The prepared mucoadhesive buccal films were evaluated for their physicochemical parameters such as weight uniformity, thickness uniformity, folding endurance, drug content, surface pH, swelling index, in vitro release studies, ex vivo mucoadhesion time, ex vivo permeation studies and stability studies. Patches exhibited controlled release for a period of 10 hrs. The mechanism of drug release was found to be Fickian diffusion and followed the zero-order kinetics. The mucoadhesive buccal patches of Ethylcellulose-Hyroxypropyl methyl cellulose in ratio of 1:4 (EH4) was concluded to be optimized. The optimized patches showed comparable swelling index, significantly higher mucoadhesive strength, higher in-vitro drug release, more mucoadhesion time and more cumulative percentage of drug permeated than mucoadhesive buccal patches of ethylcellulose-polyvinyl pyrrolidone in ratio of 1:4 (EP4). From the above results, it can be concluded that blends of hydrophobic and hydrophilic polymers is better than single polymer to obtain sustained drug release and can be used to formulate mucoadhesive buccal patches of losartan to bypass first pass metabolism and hence bioavailability of losartan.
Keywords: Losartan, mucoadhesive, buccal delivery, hydrophilic and hydrophobic polymers.
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