A Novel Thermo-Sensitive Sol-Gel Reversible Buccal Adhesive Property of Fluconazole in Situ Gel For Oral Thrush

The aim of this study was the formulation and examination of a novel thermo-responsive and bioadhesive in situ gelling drug delivery system, which can be used in the treatment of oral thrush. A bioadhesive polymer was used as a thermo responsive material, because poloxmer 188 and carbopol 934 has thermal gelation properties at certain temperature. The thermal gelation temperature 15% w/w poloxmer 188 and carbopol 934 1% w/w solutions is above body temperature, but by using different ratio of poloxmer and carbopol combination of system, it can be shifted near to body temperature. The optimized formulations were evaluated for gelling capacity, viscosity, gel strength, bioadhesive force, drug release, FTIR and DSC. Keyword: Prolong Release, Fluconazole, Poloxmer 188, Carbopol 934, Thermo-Sensitive, Oral Thrush Introduction: Polymers are the substances of high molecular weight made up of repeating monomer units. These are widely used in pharmaceutical systems as adjutants, suspending and emulsifying agents, adhesives, packaging and coating materials and increasingly, components of controlled and site specific drug delivery systems. The chemical reactivity of polymers depends upon the chemistry of their monomer units, but their properties depend to large extent on the way the monomers are put together. Polymer molecules may be linear or branched, and separate linear or branched chains may be joined by crosslink’s. Polymers in which all the monomeric units are identical are referred to as homopolymers; those formed from more than one monomer type are called copolymers. Various arrangements of monomers, say A and B lead to formation of varieties of copolymers. Copolymers may be described as alternating copolymers, block copolymers, or graft copolymers. Pluronic is one of the most widely used block copolymer and forms heterogels [1]. The use of pluronic block copolymers in experimental medicine and pharmaceutical sciences has a long history. Several excellent articles are available that provide detailed information about pluronic based formulations, particularly gels, w/o and o/w emulsions, nanoparticles coated with block copolymer and solid polymer blends [2, 3] The use of pluronic micelles in drug delivery, including issues of solubilization of water insoluble drugs, preparation of stable micellar formulations and specific applications in cancer, gene therapy and other areas, has been recently reviewed [4]. The concept of pharmaceutical excipients as non-active formulation ingredients has undergone substantial evalution [5]. This is because many excipient considered ‘inert’, in actuality display important and sometimes very useful activities, making them essential constituents of the formulation. As a result, these formulation components are referred to as ‘functional excipients’. Pluronic block copolymers fall into this functional excipient category having demonstrable effects. Poloxamers or pluronic (marketed by BASF Corporation) are the series of commercially available difunctional triblock copolymers of non-ionic nature [6]. They comprise of a central block of relatively hydrophobic polypropylene oxide surrounded on both sides by the blocks of relatively hydrophilic poly ethylene oxide [7, 8]. Due to the PEO/PPO ration of 2:1, when these molecules are immersed into the aqueous solvents, they form micellar structures above critical micellar concentration [9, 10]. They are regarded as PEO-PPO-PEO copolymers. Chemically they are Oxirane, methyl-, polymer with oxirane or α-Hydro-ωISSN:0975-542X Jayaraj Kumar et al / J Biomed Sci and Res., Vol 2 (2), 2010,100-109