Abstract:
The size and location of microsphere uptake/delivery are important determinants of the final biodistribution of oral microsphere systems. Formulations, kits, methods of administering the formulations, and using the kits are described herein. The formulations are oral dosage formulations. In one embodiment, the formulations contain microparticles and/or nanoparticles having a homogenous size range selected to optimize uptake in a specific region of the GI tract and target drug delivery to specific organs. In some embodiments, the dosage formulation contains an enteric coating and/or a magnetic material. In a preferred embodiment, the formulation contains a magnetic material and an active agent to be delivered, optionally the active agent is in the form of micro- or nano-particles. In some embodiments metallomucoadhesive materials and/or magnetic materials are employed as magnetic and/or mucoadhesive sources. Formulations containing magnetic materials can be localized using the kits and methods disclosed herein. In one embodiment, the method includes orally administering the formulation and applying an extracorporeal magnet to a site on the outside surface of the patient's body in an area that closely apposes the location in the gastrointestinal tract to which delivery of the formulation is desired. The extracorporeal magnet is applied for a suitable time period to allow for the drug to be released from the formulation and/or to allow for the formulation to adhere to the site. Both magnetic and mucoadhesive forces may be utilized to site-direct and retain the dosage form in the region of the gastrointestinal (GI) tract most suitable for the desired delivery.
Abstract:
Compositions containing particles of biologically active agents with sizes in the micron and submicron range and methods for making and using such particles are described herein. In the preferred embodiment the biologically active agents are peptides, proteins, nucleic acid molecules, or hydrophilic synthetic molecules. The particles have a size ranging from an average diameter of about 100 nm to about 2000 nm, preferably about 200 nm to 600 nm. Optionally the biologically active agents contain a polymeric coating. The particles are formed by adding a biologically active agent to an aqueous solution, mixing a nonsolvent that is miscible with water with the aqueous solution, and precipitating particles of the biologically active agents out of the nonsolvent: aqueous solution combination. The nonsolvent is typically a C1 to C6 alcohol, preferably a C2 to a C5 alcohol. In the preferred embodiment, the nonsolvent is tert-butyl alcohol.
Abstract:
Methods for inducing a thermoplastic polymer, which can be non-mesogenic, to exhibit liquid crystalline properties have been developed. The method includes the steps of (a) heating the polymer from an initial temperature below its glass transition temperature (Tg) to a temperature greater than its Tg and below its melting temperature (Tm); (b) exposing the polymer to a pressure greater than about 2 metric tons/in2, preferably between about 2 and 10 metric tons/in2, preferably for at least about one minute, while maintaining the temperature greater than its Tg; and (c) cooling the polymer below the Tg while maintaining the elevated pressure. Unlike many prior art transition processes which are reversible, this process provides a liquid crystal state that can be maintained for years at ambient conditions. In a preferred embodiment, the plastics are bioerodible thermoplastic polymers, such as polyanhydrides, some polyesters, polyamides, and polyaromatics. The liquid crystalline polymers can be used in the controlled release or retention of substances encapsulated in the polymers. The polymer can be in a variety of forms including films, film laminants, and microparticles. In a preferred embodiment, the LC polymers are used to encapsulate therapeutic, diagnostic, or prophylactic agents for use in medical or pharmaceutical applications.
Abstract:
A means for obtaining efficient introduction of exogenous genes into a patient, with long term expression of the gene, is disclosed. The gene, under control of an appropriate promoter for expression in a particular cell type, is encapsulated or dispersed with a biocompatible, preferably biodegradable polymeric matrix, where the gene is able to diffuse out of the matrix over an extended period of time, for example, a period of three to twelve months or longer. The matrix is preferably in the form of a microparticle such as a microsphere (where the gene is dispersed throughout a solid polymeric matrix) or microcapsule (gene is stored in the core of a polymeric shell), a film, an implant, or a coating on a device such as a stent. The size and composition of the polymeric device is selected to result in favorable release kinetics in tissue. The size is also selected according to the method of delivery which is to be used, typically injection or administration of a suspension by aerosol into the nasal and/or pulmonary areas. The matrix composition can be selected to not only have favorable degradation rates, but to be formed of a material which is bioadhesive, to further increase the effectiveness of transfer when administered to a mucosal surface.
Abstract:
A process for preparing nanoparticles and microparticles is provided. The process involves forming a mixture of a polymer and a solvent, wherein the solvent is present in a continuous phase and introducing the mixture into an effective amount of a nonsolvent to cause the spontaneous formation of microparticles.
Abstract:
Methods and compositions are provided for enhancing the bioadhesive properties of polymers used in drug delivery devices. The bioadhesive properties of a polymer are enhanced by incorporating a metal compound into the polymer to enhance the ability of the polymer to adhere to a tissue surface such as a mucosal membrane. Metal compounds which enhance the bioadhesive properties of a polymer include water-insoluble metal compounds such as water-insoluble metal oxides, including oxides of calcium, iron, copper and zinc. The metal compounds can be incorporated within a wide range of polymers including proteins, polysaccharides and synthetic biocompatible polymers. In one embodiment, metal oxides can be incorporated within polymers used to form or coat drug delivery devices, such as microspheres, which contain a drug or diagnostic agent. The metal oxides can be provided in the form of a fine dispersion of particles on the surface of a polymer that coats or forms the devices, which enhances the ability of the devices to bind to mucosal membranes. The polymers, for example in the form of microspheres, have improved ability to adhere to mucosal membranes, and thus can be used to deliver a drug or diagnostic agent via any of a range of mucosal membrane surfaces including those of the gastrointestinal, respiratory, excretory and reproductive tracts.
Abstract:
The present invention is a method to produce novel composites based on microcapsules or microspheres embedded in contiuous polymeric matrices. Both non-bioerodible and erodible polymers can be used. Material can be incorporated into the microcapsules or microspheres for subsequent release. In one embodiment of the present invention, spheres are homogeneously dispersed in a polymer matrix and then forced to release their contents by exposure to temperature, light or ultrasound. Alternatively, polymers which degrade as a function of time or hydrolysis can be used for controlled releases. The polymer composites have completely different properties from either a continuous polymer matrix or microcapsules or microspheres and are therefore useful for a wide variety of applications. When carbon tetrachloride is the incorporated material, the film is useful as a flame retarding device. When foaming agents are used, especially UV or heat sensitive materials, gas can be evolved inside each capsulThe Government has rights in this invention pursuant to Grant Number 5-R01-GM26698 awarded by the Department of Health and Human Services.
Abstract:
A single step method for preparation of multi-layer polymeric delivery systems. Any two or three different degradable or non-degradable polymers which are not soluble in each other at a particular concentration, as dictated by their phase diagram, can be used. The multi-layer microcapsules produced by the method are distinguished by extremely uniform dimensioned layers of polymer and actual incorporation of the substance to be delivered into the polymer layers.In the preferred embodiment of the method, two polymers are dissolved in a volatile organic solvent, the substance to be encapsulated is dispersed or dissolved in the polymer solution, the mixture is suspended in an aqueous solution and stirred, and the solvent is slowly evaporated, creating microspheres with an inner core formed by one polymer and an outer layer formed by the second polymer. In another embodiment one polymer may be formed within a layer of the other polymer by increasing the rate of evaporation of the volatile solvent.
Abstract:
An effective method for prolonging localization of therapeutics within the rat gastrointestinal tract of at least about 12 hours is provided. Attractive forces between an orally administered magnetic dose and an external magnet were monitored and internal dose motion in real time using biplanar videofluoroscopy was visualized. Tissue elasticity was quantified as a measure of tissue health by combining data streams. The methods address safety, efficacy, and monitoring capacity of magnetically localized doses and show a platform for testing the benefits of localized drug delivery.
Abstract:
Formulations of a neuroprotective agent for parenteral administration are described herein. The formulation is in the form of a concentrated (supersaturated) solution or a concentrated suspension of microparticles. The suspension medium or the solution solvent carrier may also contain dissolved neuroprotective agent. For the supersaturated solutions, the agent is dissolved at high concentrations of at least about 1% by weight, 5% by weight, 10% by weight, 15% by weight, or 20% by weight in a solvent suitable for parenteral administration. For the concentrated suspension, the microparticles have an effective particle size from about 100 nm to about 5 microns, preferably from about 50 nm to about 3 microns, more preferably from about 10 nm to about 2 microns. The formulations described herein can be used to treat a variety of neurological diseases/disorders and/or neurological injury or trauma.