Polymer-in-situ Forming Implant Systems Services

CD Formulation provides professional development services for polymer-in-situ forming implant sytems. Our services include formulation development, physical and chemical analysis, in vitro drug delivery, etc. We provide a full range of integrated services and exclusive solutions for our customers.

In-situ Forming Polymer Formulations

In-situ forming polymeric formulations are drug delivery systems that are solvated prior to in vivo administration, but once administered, gelation occurs in situ to form a gel. Gel formation is dependent on factors such as temperature regulation, pH changes, presence of ions and UV irradiation, and the drug is released from the gel in a continuous and controlled manner. The various polymers used to formulate in situ gels include gellan gum, alginate, xylan, pectin, chitosan, poly (DL-lactic acid), poly (DL-lactic acid-co-polyethylene glycol) and polycaprolactone. The choice of solvent for these formulations, such as water, dimethyl sulfoxide, N-methylpyrrolidone, triacetyl and 2-pyrrolidone, depends on the solubility of the polymers used.

Polymer-in-situ Forming Implant Systems Development

CD Formulation can customize polymer-in-situ gel formulations to meet customer needs and can provide formulation development and formulation optimization services.

• Characterization of in situ gel systems

• Viscosity and rheology testing

Viscosity and rheological properties of in situ formed drug delivery systems can be tested using a rheometer.

• Sol-gel transition temperature and gelling time testing

For in situ gel forming systems containing thermally reversible polymers, the sol-gel transition temperature can be defined as the temperature at which the phase transition of the sol meniscus is first noted when the sample tube is maintained at a specific temperature and heated at a specific rate. Gelation time is defined as the time at which gelation is first detected.

• Gel strength test

This parameter can be evaluated with a rheometer. Depending on the gelling mechanism of the gelling agent used, a specified number of gels are prepared in a beaker. The beaker containing the gel is raised at a certain rate so that the probe is slowly pushed into the gel. The change in loading on the probe can be measured as a function of the depth of probe immersion below the surface of the gel.

• In vitro drug release studies

For in situ gel formulations administered by oral, ocular or rectal routes, drug release studies are performed by using a plastic dialysis cell. The cell consists of two cell halves, a donor area and an acceptor area. The sol-gel form of the formulation is placed in the donor compartment. The assembled cells are then shaken horizontally in an incubator. The total volume of the recipient solution can be removed and replaced with fresh medium over a period of time. This receptor solution is analyzed for drug release using analytical techniques. For injectable in situ gels, the formulation is placed in vials containing receptor media and placed in a shaker water bath at a defined temperature and oscillation rate. Samples were periodically withdrawn and analyzed.

• FTIR spectroscopy and thermal analysis

Infrared spectroscopy is tested during gelation by using the potassium bromide pellet method. Thermogravimetric analysis allows the analysis of polymer systems formed in situ to quantify the percentage of water in the hydrogel.

Our services are constantly being updated, so if you want a service that is not on our list, you can contact us and our experts will customize a solution for your project.