Abstract: Reversibly gel-forming compositions for sustained delivery of bio-affecting substances are disclosed. The compositions exhibit significant changes in viscosity in response to changes in pH. The compositions contain relatively low concentrations of a stable combination of at least one pH-responsive gelling polymer and at least one other thermally nonresponsive polymer. The compositions are preferably formulated to include one or more therapeutic or diagnostic agents for administration as a liquid that will gel in situ or for topical application as a pre-formed gel.

Abstract: Sustained release pharmaceutical compound delivery compositions and methods for their production are disclosed wherein ion exchange resin particles are loaded with releasably bound pharmaceutical compounds and incorporated in an aqueous reversibly gelling polymeric solution. The pores of the ion exchange resin are sufficiently small to lock in the pharmaceutical compound without exposure to the large polymer molecules. The pharmaceutical compound remains bound within the pores of the ion exchange resin particles until after administration to a target tissue site where small ions migrate into the pores and initiate an exchange reaction.

Abstract: Pharmaceutical compositions are disclosed which effectively treat the symptoms of hypersensitivity diseases without irritation. The pharmaceutical compositions are complexes of at least one leukotriene receptor antagonist and at least one antihistamine. The complexes can be formulated in low viscosity solutions for administering to an individual as an aerosol or drops or through intravenous, subcutaneous, or intramuscular injection. Alternatively, the complexes can be formulated in high viscosity creams for topical delivery to the skin or ocular environment.

Abstract: Reversibly gelling aqueous compositions are disclosed which undergo significant changes in viscosity in response to substantially simultaneous changes in both temperature and pH. The compositions are formed of relatively low concentrations of a stable combination of at least one pH-sensitive reversibly gelling polymer and at least one temperature-sensitive reversibly gelling polymer. The compositions can be formulated to exhibit a sol-gel transition over a wide range of conditions and viscosities and may be modified to incorporate a pharmaceutical compound for utilization as droppable or injectable drug delivery systems which will gel following administration to a physiological system for the sustained delivery of such pharmaceutical compounds.

Abstract: The instant invention is directed to an osmotic pump comprising:(A) at least one active agent surrounded by(B) a rate controlling water insoluble wall, having a fluid permeability of 6.96.times.10.sup.-18 to 6.96.times.10.sup.-14 cm.sup.3 sec/g and a reflection coefficient of less than 1, prepared from:(i) a polymer permeable to water but impermeable to solute and(ii) 0.1 to 60% by weight, based on the total weight of (i) and (ii), of at least one pH insensitive pore forming additive dispersed throughout said wall.

Abstract: The instant invention is directed to a multiparticulate osmotic pump, for the controlled release of a pharmaceutically active agent to an environment of use, said pump comprising:(I) a carrier medium which does not maintain its integrity in the environment of use;(II) a multiple of tiny osmotic pump elements each consisting essentially of:(A) a core comprises at least one pharmacologically active agent soluble in an external fluid, or a mixture of an agent having a limited solubility in the external fluid with an osmotically effective solute that is soluble in the fluid, which exhibit an osmotic pressure gradient across the wall against the external fluid surrounded by(B) a rate controlling water insoluble wall, having a fluid permeability of 6.96.times.10.sup.-18 to 6.96.times.10.sup.14 cm.sup.3 sec/g and a reflection coefficient of less than 0.5, prepared from:(i) a polymer permeable to water but impermeable to solute and(ii) 0.

Abstract: The invention relates to the use of carboxylic acids incorporated as a catalyst in poly(orthoester)s and other acid labile polymers such that upon exposure to aqueous environments the acid catalyzes the erosion of the polymer matrix. The rate of release of a drug substance incorporated into or surrounded by the poly(orthoester) or other acid labile polymer can be controlled in that the drug is released as the polymer is eroded in response to the catalytic action of the acid incorporated therein.

Abstract: The invention relates to the use of an acid anhydride incorporated as a latentiated catalyst in poly(ortho ester) and other polymers such that upon exposure to aqueous environments the acid anhydride generates the corresponding acid which catalyzes the matrix erosion. The releasing rate of a loaded drug substance incorporated into or surrounded by the poly(ortho ester) or other polymers can be controlled in that the drug is released as the poly(ortho ester)s or other polymer is eroded by action of the acid anhydride incorporated therein.

Abstract: An osmotic drug (or other beneficial substance) delivery system comprises a compartment with one or more chambers in series formed by an external shell and chamber-dividing walls of a microporous material and successive overlayers of semipermeable membranes completely covering the outer shell of all but one chamber and substantially covering the outer shell of that one chamber, each successive overlayer completely covering all but one more chamber and substantially covering that one more chamber.

Abstract: Solvent regeneration of activated carbon on which a chemical species is sorbed is enhanced by the selective use of a regenerant solution containing a solvent for said chemical species and a predetermined concentration of the chemical species in solution. The stream of spent regenerant coming from the carbon is thereby made more concentrated in solute and easier to treat for separation of the solute and solvent.