The experiments were conducted in triplicate. Surface contact angle measurements The wettability of breath figure films was measured using the sessile drop method with a standard goniometer (Rame-Hart model 250) and analyzed using the DROPimage Advanced software for contact angle determination. selleck Y-27632 A 3 ��L distilled water droplet was placed on the polymer film surface and the contact angle ���ȡ� measured. The measurement was done for a minimum of five samples of a specific polymer film, and the average value reported. Typical standard deviations are of the order of 0.3. In vitro release characteristics Ibuprofen and Salicylic acid were used as model drugs to characterize the release profiles of breath figure polymer films. The equivalent non-porous smooth films were used as controls.
In vitro release studies were performed by incubating 1.5 cm side square drug incorporated films in 15 ml of PBS medium at 37��C and stirred gently using a magnetic stirrer. At specific time intervals, 0.650 ml aliquots of the solution was withdrawn and centrifuged to remove any possible debris from the degrading polymer. Then, the aliquot was returned to the vial after measuring the absorbance to quantify drug release. The pH of the medium was monitored during the course of the experiment to verify that the solution is buffered adequately during polymer degradation. Ibuprofen and salicylic acid release were quantified through the absorbance at 221 and 296 nm, respectively. Standard calibration plots of ibuprofen and salicylic acid absorbance were constructed to correlate absorbance with drug release levels.
All experiments were conducted in triplicate. Conclusions Morphological characteristics of breath figure films of degradable PLGA and PEG/PLGA materials were analyzed through scanning electron microscopy as they were allowed to degrade in vitro. The degradation pattern shows a flattening of surface structure where the walls of the surface breath figure pores are first degraded away, followed by the gradual degradation of the underlying layers. Pinprick pores extending to the base of the film are subsequently formed which evolve into larger pore structures that eventually break up the film. The morphology of the film has a significant effect on release characteristics with breath figure morphologies in general exhibiting faster release than their nonporous analogs.
Additionally the incorporation of poly (ethylene glycol) into the films enhances release rates, which we attribute to improvement of water ingress into the film. Drug release from such thin films Dacomitinib appears to follow diffusion pathways rather than a constant release rate based on degradation of the material through dissolution of surface layers. The use of breath figure morphologies in biodegradable polymer films adds an additional level of control to drug release. Coating medical devices (stents, surgical meshes, etc.