Entrapment and release characteristics of 2-methoxynaphthalene from cylindrical microstructures formed from phospholipids.

Many natural products that exhibit biocidal activity have poor solubility in water. In order to explore the prolonged delivery of these compounds from microtubules we have utilized 2-methoxynaphthalene as a model to elucidate release characteristics of hydrophobic compounds entrapped in microtubules by spectrophotometric absorbance at 255 nm. Entrapment of this compound in microcylinders was accomplished by addition of 2-methoxynaphthalene to a water-soluble epoxy, or entrapment of the neat compound. Variation of the release rate is possible for 2-methoxynaphthalene based on the mode of entrapment and by variations in the methods used to immobilize the compound within the microcylinders. Unlike conventional microencapsulation techniques which require inclusion of the active agent at the time of formation, the use of microcylinders allows for the inclusion of a variety of active agents and the tailoring of release characteristics after their formation. We report the results of in vitro release rates of 2-methoxynaphthalene from a static diffusion system designed to explore release of hydrophobic compounds into an aqueous environment.