The main aim of this study is to develop ocular drug delivery system for Natamycin; a polyene antibiotic is highly useful for the treatment of conjunctivitis and keratitis. The ocuserts were prepared using different polymers such as eudragit L-100, eudragit S-100, eudragit RL-100, hydroxy propyl methyl cellulose phthalate and cellulose acetate phthalate at various proportion and combinations using PEG-400 as plasticizer. The prepared ocuserts were evaluated for their physicochemical parameters like drug content, weight uniformity, folding endurance, thickness, % moisture absorption and water vapour transmission rate. The in vitro drug release from the formulations was studied using commercial semi permeable membrane and the in vitro release kinetic datas were treated according to the diffusion models proposed by Higuchi and Peppas in order to access the mechanism of drug release from the formulations, which were following zero order kinetics. All the formulations showed no change in the physical appearance and the FTIR studies indicated no possibility of interaction between drug and polymer. The expected zero order release for one day was observed in the formulation D1 (3% Eudragit RL100 and 1% Eudragit L100)

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For a given non-adjacent pair {x, y} in a graph G, we denote by G xy the graph obtained by deleting x and y and adding a new vertex xy adjacent to precisely those vertices of G − x − y which were adjacent to at least one of x or y in G. We say that G xy is obtained by contracting on {x, y}. In this paper we introduce γ-stable graphs and we have established that γ-stable trees have a unique structure.

Ever since the discovery of domination numbers by Claude Berge in the year 1958, graph domination has become an important domain in graph theory that has strengthened itself as a theory and has extended its contributions to various applications. Tree characterization is an important problem in graph domination. This survey focuses on presenting a collection of results on characterizing trees using domination number.