Protein Delivery by Enteric Copolymer Nanoparticles

Chitosan Nanoparticles as Oral Drug Carriers

The use of nanoparticles as drug delivery systems has increased in importance in the last decades. Despite the disadvantages of difficulty swallowing, gastric irritation, low solubility, and poor bioavailability, oral administration stands out as the most widely used route for therapeutic treatments, though it may not always be the most effective route. The effect of the first hepatic pass is one of the primary challenges that drugs must overcome to carry out their therapeutic effect. For these reasons, controlled-release systems based on nanoparticles synthesized from biodegradable natural polymers have been reported to be very efficient in enhancing oral delivery in multiple studies. Chitosan has been shown to have an extensive variability of properties and roles in the pharmaceutical and health fields; of its most important properties are the ability to encapsulate and transport drugs within the body and enhance the drug interaction with the target cells, which improves the efficacy of the encapsulated drugs. The physicochemical properties of chitosan give it the ability to form nanoparticles through multiple mechanisms, which will be addressed in this article. The present review article focuses on highlighting the applications of chitosan nanoparticles for oral drug delivery.

Development, Characterization, Optimization, and In Vivo Evaluation of Methacrylic Acid-Ethyl Acrylate Copolymer Nanoparticles Loaded with Glibenclamide in Diabetic Rats for Oral Administration

The methacrylic acid–ethyl acrylate copolymer nanoparticles were prepared using the solvent displacement method. The independent variables were the drug/polymer ratio, surfactant concentration, Polioxyl 40 hydrogenated castor oil, the added water volume, time, and stirring speed, while size, PDI, zeta potential, and encapsulation efficiency were the response variables analyzed. A design of screening experiments was carried out to subsequently perform the optimization of the nanoparticle preparation process. The optimal formulation was characterized through the dependent variables size, PDI, zeta potential, encapsulation efficiency and drug release profiles. In vivo tests were performed in Wistar rats previously induced with diabetes by administration of streptozotocin. Once hyperglycemia was determined in rats, a suspension of nanoparticles loaded with glibenclamide was administered to them while the other group was administered with tablets of glibenclamide. The optimal nanoparticle formulation obtained a size of 18.98 +/− 9.14 nm with a PDI of 0.37085 +/− 0.014 and a zeta potential of −13.7125 +/− 1.82 mV; the encapsulation efficiency was of 44.5%. The in vivo model demonstrated a significant effect (p < 0.05) between the group administered with nanoparticles loaded with glibenclamide and the group administered with tablets compared to the group of untreated individuals.

Development and evaluation of ivabradine microspheres for controlled release

The objective of this study was to formulate and evaluate controlled release formulations of ivabradine hydrochloride (HCl)-loaded microspheres consisting of Kollicoat MAE 100 P and ethyl cellulose prepared by the oil-in-oil solvent evaporation method. The drug was encapsulated into microspheres by an in situ method by varying the polymer contents. The resultant microspheres were characterized with respect to drug loading, flow properties, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffractometry (XRD), thermal analysis and release behavior. Chemically stable loaded microspheres were confirmed by FTIR, differential scanning calorimetry (DSC), thermogravimetric analysis and XRD. SEM images showed that the microspheres were spherical with smooth surfaces. FTIR spectra confirmed the presence of the drug in pure form and revealed no interaction between the drug and polymers. XRD and DSC were conducted to determine the nature of the drug in drug-loaded microspheres, and the results revealed that the drug was present in amorphous form. The maximum percentage entrapment efficiency was found to be 82 ± 2·11%, and the percentage yield was 89 ± 3·31%. The maximum in vitro drug release was more than 90% for pH 7·4, which demonstrated that drug-loaded formulations had a pH-dependent drug release. Cumulative drug release data were analyzed by using different kinetic models. The Korsmeyer–Peppas equation was used to determine the value of n which follows non-Fickian diffusion.