Microspheres & Microneedles In Vitro Release Testing

The release behavior is jointly determined according to the clinical indication requirements and the properties of the prepared materials. Select appropriate materials and processes to prepare drug-loaded microspheres and microneedles with different structures, so that the active ingredients can be released according to the expected pharmacokinetic model. For biodegradable materials, swelling and erosion mechanisms are also major factors controlling drug release. The composition, pH value, ionic strength, osmotic pressure and temperature of the release medium will all affect the release rate.

The measurement of microsphere and microneedle in vitro release test provided by CD Formulation is to test and evaluate the release amount and release rate of the drug within a certain period of time after administration, and to investigate the release behavior of the drug carrier.

How to Perform In Vitro Release Testing of Microspheres & Microneedles

The degree and speed of drug release in vitro can effectively reflect various physical and chemical parameters such as drug solubility, particle size, and rheological properties of dosage forms and their comprehensive effects. With the help of this research, the influence of different prescriptions and processes on the drug loading of microspheres and microneedles can be identified, which is an important project in the process of drug development, quality control, and stability research. CD Formulation can provide the following in vitro release tests of microspheres and microneedles to evaluate the drug loading and drug release capabilities of the carrier.

In vitro release test of microspheres

For drug-loaded microspheres with a long release period, an accelerated release test method can be established to predict and simulate the conventional release behavior. The establishment of accelerated release conditions should follow the principle of correlation, so that the accelerated release curve can be fitted to the conventional release curve as much as possible to obtain an accurate correlation.

The in vitro release methods of microsphere preparations mainly include:

Direct drug release method, which is the most commonly used method at present, includes shaking table method and constant temperature water bath static method. The microsphere preparation is placed in a container containing a medium to keep it closed at a constant temperature, and samples are taken for a certain period of time and fresh medium is added.

Flow cell method, the system consists of a constant flow pump, a temperature-controlled flow cell, a storage bottle, a filtration system, a sampling system, and a sample collection system.

Dialysis membrane diffusion method, this method refers to putting the microspheres into the dialysis tubing and putting them into the medium for determination.

In vitro release test of microneedles

Wrap the microneedle sheet with polytetrafluoroethylene and tin foil, and the needle body of the microneedle is partially exposed. Add phosphate buffer, put the wrapped microneedle sheet into a 24-well plate with the needle tip facing down, cover it, put it in a constant temperature shaker for in vitro release experiments, and take samples at different time points. After each sampling, pour out the release solution remaining in the 24-well plate, wash the 24-well plate with new PBS buffer, add the release solution, and continue the subsequent in vitro release experiment.

In addition to providing you with in vitro release testing services for microspheres and microneedles, CD Formulation can also provide you with analysis and evaluation of release capabilities and provide solutions. If you are interested in this kind of service, please contact us in time, and we will customize exclusive experimental plans and solutions for you.