Production of Isotonic, Sterile, and Kinetically Stable Lipid-Core Nanocapsules for Injectable Administration.

Lipid-core nanocapsules (LNC) were designed and prepared as a colloidal system for drug targeting to improve the stability of drugs and allow their controlled release. For parenteral administration, it is necessary to ensure formulation sterility. However, sterilization of nanotechnological devices using an appropriate technique that keeps the supramolecular structure intact remains a challenge. This work aimed to evaluate the effect of autoclaving on the physicochemical characteristics of LNC. Formulations were prepared by the self-assembling method, followed by isotonization and sterilization at varying times and temperatures. The isotonicity was confirmed by determining the freezing temperature, which was -0.51°C. The formulation was broadly characterized, and the diameter of the particles was determined utilizing complementary methods. To evaluate the chemical stability of poly(ε-caprolactone), its molecular weight was determined by size exclusion chromatography. The physicochemical characteristics (average diameter, viscosity, and physical stability) of the formulation were similar before and after adding glycerol and conducting the sterilization at the highest temperature (134°C) and the shorter exposure time (10 min). After autoclaving, the sterility test was performed and showed no detectable microbial growth. Multiple light scattering demonstrated that the formulations were kinetically stable, and the mean diameter was constant for 6 months, corroborating this result. The polymer was chemically stable in the sterilized formulation. Isotonic and sterile LNC aqueous suspensions were produced using glycerol and autoclaving. Briefly, the results open an opportunity to produce an isotonic and sterile LNC aqueous dispersion applicable as nanomedicine for intravenous administration in clinical trials.

Development of Novel Chitosan Microcapsules for Pulmonary Delivery of Dapsone: Characterization, Aerosol Performance, and In Vivo Toxicity Evaluation.

Pneumocystis carinii pneumonia (PCP) is a major opportunistic infection that affects patients with human immunodeficiency virus. Although orally administered dapsone leads to high hepatic metabolism, decreasing the therapeutic index and causing severe side effects, this drug is an effective alternative for the treatment of PCP. In this context, microencapsulation for pulmonary administration can offer an alternative to increase the bioavailability of dapsone, reducing its adverse effects. The aim of this work was to develop novel dapsone-loaded chitosan microcapsules intended for deep-lung aerosolized drug delivery. The geometric particle size (D 4,3) was approximately 7 µm, the calculated aerodynamic diameter (d aero) was approximately 4.5 µm, and the mass median aerodynamic diameter from an Andersen cascade impactor was 4.7 µm. The in vitro dissolution profile showed an efficient dapsone encapsulation, demonstrating the sustained release of the drug. The in vitro deposition (measured by the Andersen cascade impactor) showed an adequate distribution and a high fine particles fraction (FPF = 50%). Scanning electron microscopy of the pulmonary tissues demonstrated an adequate deposition of these particles in the deepest part of the lung. An in vivo toxicity experiment showed the low toxicity of the drug-loaded microcapsules, indicating a protective effect of the microencapsulation process when the particles are microencapsulated. In conclusion, the pulmonary administration of the novel dapsone-loaded microcapsules could be a promising alternative for PCP treatment.

Intranasal administration of budesonide-loaded nanocapsule microagglomerates as an innovative strategy for asthma treatment.

The co-existence with rhinitis limits the control of asthma. Compared with oral H1 receptor antagonists, intranasal corticosteroids have been demonstrated to provide greater relief of all symptoms of rhinitis and are recommended as first-line treatment for allergic rhinitis. Intrinsic limitations of nasal delivery, such as the presence of the protective mucous layer, the relentless mucociliary clearance, and the consequent reduced residence time of the formulation in the nasal cavity, limit budesonide efficacy to the treatment of local nasal symptoms. To overcome these limitations and to enable the treatment of asthma via nasal administration, we developed a budesonide-loaded lipid-core nanocapsule (BudNC) microagglomerate powder by spray-drying using a one-step innovative approach. BudNC was obtained, as a white powder, using L-leucine as adjuvant with 75 ± 6% yield. The powder showed a bimodal size distribution curve by laser diffraction with a principal peak just above 3 µm and a second one around 0.45 µm and a drug content determined by HPLC of 8.7 mg of budesonide per gram. In vivo after nasal administration, BudNC showed an improved efficacy in terms of reduction of immune cell influx; production of eotaxin-1, the main inflammatory chemokine; and arrest of airways remodeling when compared with a commercial budesonide product in both short- and long-term asthma models. In addition, data showed that the results in the long-term asthma model were more compelling than the results obtained in the short-term model. Graphical abstract.

Nanoencapsulation of olanzapine increases its efficacy in antipsychotic treatment and reduces adverse effects.

Olanzapine is an atypical antipsychotic drug, whose chronic use has been associated with the development of potential adverse effects such as weight gain and cardio-metabolic disorders like hypercholesterolemia and diabetes. To circumvent these side effects, the controlled release of olanzapine is a promising approach to improve adhesion of schizophrenic patients to the treatment. An innovative strategy to prolong drug release consists of loading the drug into biodegradable polymeric lipid-core nanocapsules. In this study, particle size, polydispersity, pH, zeta potential and drug loading of olanzapine-loaded lipid-core nanocapsules were analyzed. Weight gain, biochemical parameters and antipsychotic activity were evaluated in male Wistar rats. The lipid-core nanocapsules had a mean diameter of 156 +/- 13 nm, a polydispersity index lower than 0.1, a pH value of 6.12 +/- 0.14, zeta potential of -17 +/- 2.40 mV and encapsulation efficiency close to 100%. The animals treated with olanzapine-loaded lipid-core nanocapsules showed significantly lower weight gain (63.4 +/- 19.6 g) and total cholesterol levels (66.2 +/- 3.5 g x dl(-1)), compared to those administered with free olanzapine (112.6 +/- 10.3 g and 90.4 +/- 2.4 g x dl(-1)), respectively. Additionally, a more prolonged antipsychotic action was observed in the stereotyped behavior animal model induced by D,L-amphetamine, which affords to conclude that nanoencapsulation is a promising alternative to treat schizophrenic patients.