Fabrication and evaluation of Eudragit® polymeric films for transdermal delivery of piroxicam

The aims of this work were to develop and characterize the prolonged release piroxicam transdermal patch as a prototype to substitute oral formulations, to reduce side effects and improve patient compliance. The patches were composed of film formers (Eudragit^®) as a matrix backbone, with PVC as a backing membrane and PEG200 used as a plasticizer. Results from X-ray diffraction patterns and Fourier transform-infrared spectroscopy indicated that loading piroxicam into films changed the drug crystallinity from needle to an amorphous or dissolved form. Piroxicam films were prepared using Eudragit^® RL100 and Eudragit^® RS100 as film formers at various ratios from 1:0 to 1:3. Films prepared solely by Eudragit^® RL100 showed the toughest and softest film, while other formulations containing Eudragit^® RS100 were hard and brittle. Drug release kinetic data from the films fitted with the Higuchi model, and the piroxicam release mechanism was diffusion controlled. Among all formulation tested, Eudragit^® RL100 films showed the highest drug release rate and the highest drug permeation flux across human epidermal membrane. Increasing drug loading led to an increase in drug release rate. Eudragit^® can be used as a film former for the fabrication of piroxicam films.     

Cetyl palmitate-based NLC for topical delivery of Coenzyme Q(10) - development, physicochemical characterization and in vitro release studies.

In the present study, nanostructured lipid carriers (NLC) composed of cetyl palmitate with various amounts of caprylic/capric triacylglycerols (as liquid lipid) were prepared and Coenzyme Q(10) (Q(10)) has been incorporated in such carriers due to its high lipophilic character. A nanoemulsion composed solely of liquid lipid was prepared for comparison studies. By photon correlation spectroscopy a mean particle size in the range of 180-240nm with a narrow polydispersity index (PI) lower than 0.2 was obtained for all developed formulations. The entrapment efficiency was 100% in all cases. The increase of oil loading did not affect the mean particle size of NLC formulations. NLC and nanoemulsion, stabilized by the same emulsifier, showed zeta potential values in the range -40/-50mV providing a good physical stability of the formulations. Scanning electron microscopy studies revealed NLC of disc-like shape. With respect to lipid polymorphism, a decrease in the ordered structure of NLC was observed with the increase of both oil and Q(10) loadings, allowing therefore high accommodation for Q(10) within the NLC. Using static Franz diffusion cells, the in vitro release studies demonstrated that Q(10)-loaded NLC possessed a biphasic release pattern, in comparison to Q(10)-loaded nanoemulsions comprising similar composition of which a nearly constant release was observed. The NLC release patterns were defined by an initial fast release in comparison to the release of NE followed by a prolonged release, which was dependent on the oil content.     

Vaccine potential of recombinant saposin-like protein 2 against Fasciolosis gigantica in mice

Saposin-like protein 2 (SAP-2) is a protein that adult of Fasciola spp. use to lyse plasma membrane of red blood cells, so that their contents can be digested by proteases for the parasites’ nutrients. Thus SAP-2 is a plausible target for vaccination against these parasites. Recombinant Fasciola gigantica saposin-like protein 2 (rFgSAP-2) was expressed in Escherichia coli BL21 (DE3). A vaccination was performed in ICR mice (n = 10) by subcutaneous injection with 50 μg of rFgSAP-2 combined with Freund's adjuvant. At 2 weeks after the second boost, mice were infected with 30 F. gigantica metacercariae by oral route. The percentages of protection of rFgSAP-2 vaccine against F. gigantica were estimated to be 76.4–78.5% when compared with non vaccinated-infected and adjuvant-infected controls, respectively. The antibodies in immune sera of vaccinated mice were shown by immuno-blotting to react with native FgSAP-2 in the extract of 2- and 4-week-old juvenile parasites. By determining the levels of IgG1 and IgG2a in the immune sera, which are indicative of Th2 and Th1 immune responses, it was found that both Th1 and Th2 humoral immune response were significantly increased in rFgSAP-2 immunized group compared with the control groups, with higher levels of Th2 (IgG1) than Th1 (IgG2a). The levels of serum aspartate aminotransferase (AST) and alanine transaminase (ALT) in rFgSAP-2-immunized group showed no significant difference from those of the non-immunized and infected group, indicating that early juvenile parasites induced liver parenchyma damage, even though the numbers of worm recoveries were significantly different. This study indicates that rFgSAP-2 has a high potential as a vaccine candidate against F. gigantica in mice, and this potential will be tested in larger economic animals.     

Niosomal delivery of pumpkin seed oil: development,characterisation, and physical stability

Pumpkin seed oil (PSO) provides many health benefits including antioxidant, cardiovascular health boost, treatment of benign prostatic hyperplasia (BPH), and reduction of hair loss. The main objective of this study was to design a suitable formulation of niosomes encapsulated PSO for topical delivery. Formulation of PSO-loaded niosomes was optimised by altering the types of surfactant and the amount of PSO:surfactant:cholesterol. The developed PSO-loaded niosomes were spherical shape with the size range of 138–366?nm. The niosomes formulated with Tween 20 provided the smallest particle size. An increase in the ratio of PSO:surfactant:cholesterol from 2:2:1 to 2:4:1 led to reduction of the particle size of the niosomes. The PSO-loaded niosomes formulation F1 (PSO:Tween 20:cholesterol = 2:2:1) provided the highest percent entrapment efficacy at 75.99?±?14.65%. The in vitro release study suggested that the release mechanism was followed Korsmeyer–Peppas. The physical stability study indicated good stability over 3?months of storage at 30?°C.     

Physicochemical characterization and in vitro release studies of ascorbyl palmitate-loaded semi-solid nanostructured lipid carriers (NLC gels)

The aim of this study was to characterize the physicochemical properties and to study in vitro release of ascorbyl palmitate from semi-solid lipid nanoparticles based on nanostructured lipid carriers (NLC gels) systems with the desired viscosity for dermal delivery. NLC gels were obtained by a one-step production procedure employing a high pressure homogenization technique using different solid lipid matrices. Ascorbyl palmitate (AP) was selected as a lipophilic active ingredient due to its range of cosmetic applications. After the production, particles within the size range 170-250 nm having polydispersity index lower than 0.3 were obtained from all formulations. After the AP incorporation into the NLC gels, the zeta potential increased to values higher than |30 mV|. Almost 100% encapsulation efficiency was observed. The obtained SEM and AFM data revealed non-spherical shaped nanoparticles. From DSC and X-ray diffraction studies, it was shown that the lipid recrystallized in the solid state possessing a less ordered structure as compared to the bulk material. The release study of active-loaded NLC gel formulations using Franz diffusion cells revealed that the type of lipid matrix affects both the rate and the release pattern. The viscoelastic measurements revealed a more elastic than viscous behaviour of NLC formulations indicating a typical gel-like structure.     

Molecular cloning,characterization and functional analysis of a novel juvenile-specific cathepsin L of Fasciola gigantica

Cathepsin L proteases are a major class of endopeptidases expressed at a high level in Fasciola parasites. Several isoforms of cathepsin L were detected and they may perform different functions during the parasite development. In this study, a complete cDNA encoding a cathepsin L protease was cloned from a newly excysted juvenile (NEJ) cDNA library of Fasciola gigantica and named FgCatL1H. It encoded a 326 amino acid preproenzyme which shared 62.8–83.1% and 39.5–42.9% identity to Fasciola spp. and mammalian cathepsins L, respectively. All functionally important residues previously described for cathepsin L were conserved in FgCatL1H. Phylogenetic analysis demonstrated that FgCatL1H belonged to a distinct group, clade 4, with respect to adult and other juvenile Fasciola cathepsin L genes. FgCatL1H expression was detected by RT-PCR, using gene specific primers, in metacercariae and NEJ, and the expression gradually decreased in advanced developmental stages. A recombinant proFgCatL1H (rproFgCatL1H) was expressed in the yeast Pichia pastoris, affinity purified, and found to migrate in SDS-PAGE at approximately 47.6 and 38.3 kDa in glycosylated and deglycosylated forms, respectively. The molecular mass of the activated mature rFgCatL1H in glycosylated form was approximately 40.7 kDa. Immunoblotting and immunohistochemistry using rabbit antibodies against rproFgCatL1H showed that FgCatL1H was predominantly expressed in epithelial cells of the digestive tract of metacercariae, NEJs and juveniles of F. gigantica. FgCatL1H could cleave the synthetic fluorogenic substrate Z-Phe-Arg-MCA preferentially over Z-Gly-Pro-Arg-MCA at an optimum pH of 6.5. It also showed hydrolytic activity against native substrates, including type I collagen, laminin, and immunoglobulin G (IgG) in vitro, suggesting possible roles in host tissue migration and immune evasion. Therefore, the FgCatL1H is a possible target for vaccine and chemotherapy for controlling F. gigantica infection.     

Mobile health technology and home hospice care: promise and pitfalls

With the increasing use of mobile devices (e.g., smart phones, tablets) in our everyday lives, people have the ability to communicate and share information faster than ever before. This has led to the development of promising applications aimed at improving health and healthcare delivery for those with limited access. Hospice care, which is commonly provided at home, may particularly benefit from the use of this technology platform. This commentary outlines several potential benefits and pitfalls of incorporating mobile health (mHealth) applications into existing home hospice care while highlighting some of the relevant telemedicine work being done in the palliative and End-of-Life care fields.     

Development of ascorbyl palmitate nanocrystals applying the nanosuspension technology

Ascorbyl palmitate (AP) is an antioxidant used in both cosmetics and food industry. Owing to its poor solubility and instability caused by oxidation having been observed in several colloidal systems, the aim of this study was to investigate the feasibility of applying the nanosuspension technology by high-pressure homogenization (HPH) (DissoCubes) technology) to enhance the chemical stability of AP, followed by lyophilization. Sodium dodecyl sulfate (SDS) and Tween 80 were chosen as emulsifying agents to stabilize the developed AP nanosuspensions. After 3 months of storage at three different temperatures (4 degrees C, 25 degrees C and 40 degrees C), the photon correlation spectroscopy (PCS) analysis of AP nanosuspensions revealed that the mean particle size of those stabilized with SDS significantly increased compared to those stabilized with Tween 80. The results observed from both atomic force microscopy (AFM) and scanning electron microscopy (SEM) revealed AP nanocrystals of cubic-like shape. The percentage of AP remaining in nanosuspensions stabilized with Tween 80 was higher than 90% after 3 months storage at 4 degrees C, 25 degrees C and 40 degrees C. To increase the chemical stability of AP nanosuspensions, a drug powder was prepared by lyophilization. The effect of the presence of cryoprotectant trehalose on the physical stability was evaluated at different concentrations. After redispersing the lyophilized product, the mean size of AP nanosuspensions without trehalose was significantly higher compared with the system with trehalose. After 3 months of storage at 25 degrees C the mean size of lyophilized AP nanosuspensions remained constant. X-ray diffraction revealed the crystalline character of AP nanocrystals after HPH and lyophilization.