Loading...
5 results
Search Results
Now showing 1 - 5 of 5
- Evaluation of the biocompatibility and skin hydration potential of vitamin E-loaded lipid nanosystems formulations: in vitro and human in vivo studiesPublication . Vaz, S.; Silva, R.; Amaral, M.H.; Martins, E.; Lobo, J.M. Sousa; Silva, Ana CatarinaLipid-based nanosystems, such as nanostructured lipid carriers (NLC) and nanoemulsions (NE) have been described as promising alternatives to conventional formulations for increase skin hydration. Besides, these systems have been used as efficient vehicles for lipophilic molecules that improve skin properties (e.g. vitamin E). In this study, we performed comparative investigations between hydrogels formulations containing vitamin E-loaded NLC (HG-NLCVE) and vitamin E-loaded nanoemulsion (HG-NEVE). The experiments started with particle size measurements, which showed no significant differences between nanoparticles/nanodroplets sizes after incorporation in the hydrogel net (386 nm vs. 397 nm for HG-NLCVE and 402 nm vs. 514 nm for HG-NEVE). Afterwards, in vitro biocompatibility studies in human keratinocytes were carried out, being observed that the lipid-based nanosystems were more cytotoxic for the cells before incorporation in the hydrogel. Finally, the formulations hydration potential and sensory attributes for skin application were evaluated by in vitro occlusion tests and in vivo human experiments. The results showed that the HG-NLCVE exhibited the best occlusive properties, whereas the HG-NEVE performed a faster skin hydration effect. Furthermore, the latter was selected as the most attractive for skin application, although the HG-NLCVE was described as more suitable to obtain a long-lasting effect. This study demonstrated the in vitro and in vivo safety and hydration potential of hydrogels containing vitamin E-loaded lipid-based nanosystems. These results establish a basis to assess the cutaneous use of these systems, despite more in vivo experiments, for longer periods and in more volunteers, are required before commercialization.
- Lipid nanoparticles for the delivery of biopharmaceuticalsPublication . Silva, Ana Catarina; Amaral, M.H.; Lobo, J.M. Sousa; Lopes, Carla MartinsBiopharmaceuticals comprise therapeutic protein-based, nucleic acids and cell-based products. According to their therapeutic success, the clinical use of these products has been growing. Therefore, the development of efficient biopharmaceuticals delivery systems, which overcome their limitations for administration, remains an excellent prospect for pharmaceutical technologists. In this area, lipid nanoparticles have been increasingly recognized as one of the most promising delivery systems, due to their exclusive advantages. However, no clinical biopharmaceutical lipid nanoparticle-based products are yet available. This fact could be explained by the lack or failure of in vivo studies, regarding stability and toxicological concerns, and also by the complex regulatory issues that must be accomplished. The present review article focuses on the different classes of biopharmaceuticals, their characteristics and limitations for administration. A state of the art regarding the use of lipid nanoparticles to improve biopharmaceuticals delivery is presented and a critical prospect of the future directions that should be addressed by pharmaceutical technologists is also discussed.
- Characterization and biocompatibility evaluation of cutaneous formulations containing lipid nanoparticlesPublication . Eiras, F.; Amaral, M.H.; Silva, R.; Martins, E.; Lobo, J.M. Sousa; Silva, Ana CatarinaNanostructured lipid carriers (NLC) are well-known systems that show effectiveness to improve skin hydration, being suggested for cosmetic and dermatological use. Nonetheless, NLC dispersions present low viscosity, which is non-attractive for cutaneous application. To circumvent this drawback, the dispersions can be gelled or incorporated in semisolid systems, increasing the final formulation consistency. In this study, we prepared a hydrogel based on NLC containing vitamin E (HG-NLCVE) and evaluated its suitability for cutaneous application. The experiments started with the HG-NLCVE characterization (organoleptic analysis, accelerated stability, particle size, morphology, pH, texture and rheology). Afterwards, in vitro experiments were carried out, evaluating the formulation biocompatibility (MTT and Neutral Red) and irritant potential (Hen's egg test on the chorioallantoic membrane, HET-CAM) for cutaneous application. The results showed that the HG-NLCVE has adequate features for skin application, is biocompatible and non-irritant. From this study, it was predicted the in vivo irritant potential of the developed formulation, avoiding the need to perform a high number of tests on human volunteers. Regarding vitamin E and NLC potential to improve skin hydration, we suggest that the HG-NLCVE could be used in cosmetic (e.g. moisturizers and anti-aging) or dermatologic (e.g. xerosis and other skin disorders) products.
- Pessaries containing Nanostructured Lipid Carriers (NLC) for prolonged vaginal delivery of progesteronePublication . Correia, A.; Costa, C.P.; Silva, V.; Silva, R.; Lobo, J.M. Sousa; Silva, Ana CatarinaProgesterone (PRG) plays a crucial role in the female reproductive system, being the vaginal route the most adequate for its administration, as this drug has an extensive hepatic first pass effect. Nonetheless, vaginal PRG dosage forms originate immediate drug release and requires repeated administrations, which is unpleasant. Thereby, it is necessary to develop alternative delivery systems for prolonged vaginal release of PRG. The objective of this work was the development of pessaries for the prolonged vaginal delivery of PRG. Studies began with the preparation of an aqueous dispersion of PRG-loaded NLC (NLC_PRG), followed by the evaluation of its biocompatibility in human immortalized keratinocytes (HaCat cells), using three different methods (neutral red uptake, resazurin reduction and sulforhodamine B assays). Finally, the NLC_PRG was incorporated into pessaries, which were further characterized according to the European Pharmacopoeia to assess their suitability to prolong PRG release through the vaginal route. The results showed that, after preparation, 90% of the NLC_PRG had sizes equal or lower than 315.60 ± 0.01 nm, and an EE of 96.42 ± 0.00%. All the assays used to assess the biocompatibility of NLC_PRG showed the absence of cytotoxicity towards HaCaT cells for concentrations up to 10 μg/mL. In all cytotoxicity assays, a cytotoxic effect was only observed for concentrations equal or higher than 25 μg/mL, which provides high confidence in the obtained results. The outcomes of this study suggest the suitability of using pessaries containing PRG-loaded NLC for sustained drug release, which is an innovative therapeutic strategy and constitutes a promising alternative for the vaginal use of PRG. However, further ex vivo and in vivo studies are needed to fully clarify the pharmacokinetic and toxicological profile before reaching the clinical use.
- Intranasal lipid nanoparticles for the treatment of neurodegenerative diseasesPublication . Cunha, S.; Almeida, H.; Amaral, M.H.; Lobo, J.M. Sousa; Silva, Ana CatarinaBackground: treatments for neurodegenerative diseases are challenging, due to the absence of fully effective medicines. One of the major problems associated to these is the occurrence of non-targeting events, which leads to adverse effects and requires frequent dose administration. Methods: Researches have been performed to develop new drug delivery systems administrated by alternative routes. For example, the direct nose-to-brain delivery of drugs by means of lipid nanoparticles, such as solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC), has been showing promising results. Results: Among the advantages of intranasal administration is the avoidance of passing the blood-brain barrier (BBB) to reach the central nervous system (CNS), allowing the direct delivery of drugs to the brain by a noninvasive way, minimizing systemic exposure and prolonging residence time. This review article discusses the advantages of using SLN and NLC for direct nose-to-brain drug delivery. A brief reference to other lipid-based carriers (liposomes, nanoemulsions and microemulsions) is also provided. Conclusion: The benefits of using SLN and NLC for improve nasal drug delivery have been demonstrated by in vitro, ex vivo and in vivo experiments. However, more in vivo animal studies are needed for advance to human clinical trials and reach clinics.