ABSTRACT
To develop an industrially practical thermosensitive injectable hydrogel that is easy to administer, gels quickly in the body and allows sustained release of the drug, poloxamer-based hydrogels containing piroxicam as a model drug were prepared with poloxamer, sodium hydroxide and sodium chloride using the cold method. Their rheological characterization, dissolution and pharmacokinetics after intramuscular administration to rabbits were evaluated. Among the ingredients tested, sodium hydroxide and piroxicam decreased the viscosity and retarded the gelation time of the injectable gel. However, sodium chloride did the opposite. The thermosensitive injectable gel composed of 2.5% piroxicam, 15% P 407, 17% P 188, 0.01% sodium hydroxide and 1.6% sodium chloride was instantly applied to practical industrial product, since it was easy to administer intramuscularly and gelled quickly in the body. The drug was dissolved out of the hydrogels by Fickian diffusion through the extramicellar aqueous channels of the gel matrix. Sodium chloride barely affected the dissolution mechanism or dissolution rate of the drug from the injectable gels. Furthermore, it maintained the plasma concentrations of drug for 4 days and gave a 150-fold higher AUC compared to piroxicam solution. Thus, it would be practically useful for delivering piroxicam in a pattern that allows sustained release for a long time, leading to better bioavailability.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Drug Carriers , Hydrogels , Piroxicam/administration & dosage , Poloxamer/chemistry , Rheology , Technology, Pharmaceutical/methods , Animals , Anti-Inflammatory Agents, Non-Steroidal/blood , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Anti-Inflammatory Agents, Non-Steroidal/pharmacokinetics , Area Under Curve , Biological Availability , Chemistry, Pharmaceutical , Delayed-Action Preparations , Diffusion , Drug Compounding , Female , Injections, Intramuscular , Piroxicam/blood , Piroxicam/chemistry , Piroxicam/pharmacokinetics , Rabbits , Sodium Chloride/chemistry , Sodium Hydroxide/chemistry , Solubility , Temperature , ViscosityABSTRACT
To develop a 13C-urea-containing capsule for more economic and sensitive diagnosis of Helicobacter pylori infection, the 13C-urea-containing capsules were prepared with various additives such as polyethylene glycol, microcrystalline cellulose, sodium lauryl sulfate and citric acid. Their dissolution test and 13C-urea Breath Test in human volunteers were then performed. Polyethylene glycol increased the initial dissolution rates of urea and difference delta 13C values from 13C-urea, while microcrystalline cellulose and sodium lauryl sulfate decreased them. Irrespective of addition of citric acid, the compositions with polyethylene glycol showed higher values from 13C-urea compared to a commercial 76 mg 13C-urea-containing capsule due to higher initial dissolution rate. The capsules with 38 mg 13C-urea and 1.9 mg polyethylene glycol, which showed higher Helicobacter pylori-positive value of about 8 per thousand at 10 min, improved the sensitivity of 13C-urea in human volunteers. Thus, the 13C-urea-containing capsule with polyethylene glycol would be a more economical and sensitive preparation for diagnosis of Helicobacter pylori infection.
