Injectable emulsion containing a medicament, a thixotropic agent and membe-forming substance having ion-exchange properties. The membrane-forming substance being a polymerizable monomer which polymerizes by reaction with a polymerizing agent.
The bitter taste of ranitidine may be masked by forming an adsorbate with a synthetic cation exchange resin. The adsorbate is particularly suitable for use in pharmaceutical compositions for oral administration such as chewable or suckable tablets, granules and aqueous or non-aqueous suspensions.
A sustained absorption theophylline-containing pellet for oral administration comprises a core of theophylline or a pharmacological equivalent thereof and an organic acid embedded in a polymeric material in a multi-layer arrangement and an outer membrane which permits release of the theophylline at a controlled rate in an aqueous medium. The pellet has a dissolution rate in vitro in an aqueous medium, which when measured in a basket assembly according to U.S. Pharmacopoeia XX at 37.degree. C. and 75 r.p.m., is not more than 15% of the total theophylline after 2 hours of measurement in a buffer solution at pH 7.5. Not more than 35% of the total theophylline is released after a total of 7 hours of measurement and not more than 65% of the total theophylline is released after a total of 13 hours.
The bitter taste of ranitidine may be masked by forming an adsorbate with a synthetic cation exchange resin. The adsorbate is particularly suitable for use in pharmaceutical compositions for oral administration such as chewable or suckable tablets, granules and aqueous or non-aqueous suspensions.
A sustained absorption theophylline-containing pellet for oral administration comprises a core of theophylline or a pharmacological equivalent thereof and an organic acid embedded in a polymeric material in a multi-layer arrangement and an outer membrane which permits release of the theophylline at a controlled rate in an aqueous medium. The pellet has a dissolution rate in vitro in an aqueous medium, which when measured in a basket assembly according to U.S. Pharmacopoeia XX at 37.degree. C. and 75 r.p.m., is not more than 15% of the total theophylline after 2 hours of measurement in a buffer solution at pH 7.5. Not more than 35% of the total theophylline is released after a total of 7 hours of measurement and not more than 65% of the total theophylline is released after a total of 13 hours.
Delivery of bioactive molecules such as nucleic acid molecules encoding a protein can be significantly enhanced by immobilization of the bioactive molecule in a polymeric material adjacent to the cells where delivery is desired, where the bioactive molecule is encapsulated in a vehicle such as liposomes which facilitates transfer of the bioactive molecules into the targeted tissue. Targeting of the bioactive molecules can also be achieved by selection of an encapsulating medium of an appropriate size whereby the medium serves to deliver the molecules to a particular target. For example, encapsulation of nucleic acid molecules or biologically active proteins within biodegradable, biocompatible polymeric microparticles which are appropriate sized to infiltrate, but remain trapped within, the capillary beds and alveoli of the lungs can be used for targeted delivery to these regions of the body following administration to a patient by infusion or injection.
