Nanostructured Lipid Carriers Gel Research Articles

Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) enriched hydrogels for transdermal delivery of flurbiprofen: formulation, in vitro characterisation, pharmacokinetic and pharmacodynamic studies in animals

Aqueous dispersions of flurbiprofen solid lipid nanoparticles (FLUSLN) and flurbiprofen nanostructured lipid carriers (FLUNLC) by hot homogenisation followed by sonication technique were prepared and then incorporated into the freshly prepared hydrogels for transdermal delivery. They are characterised for particle size, DSC, shape and surface morphology, in vitro drug release, rheological behaviour and in vivo studies. The pharmacokinetics of flurbiprofen in rats following application of SLN gel (A1) and NLC gel (B1) for 24h were evaluated. The Cmax of the NLC gel formulation was 38.67 ± 2.77 μg/ml, which was significantly higher than the SLN gel formulation (Cmax = 21.79 ± 2.96 μg/ml). The bioavailability of flurbiprofen with reference to oral administration was found to increase by 4.4 times when gel formulations were applied. Anti-inflammatory effect in the carrageenan-induced paw edema in rat was significantly higher for NLC gel and SLN gel formulation than the orally administered flurbiprofen. Both the SLN and NLC dispersions and gels enriched with SLN and NLC possessed a sustained drug release over period of 24h.

Formulation and Evaluation of Lidocaine Lipid Nanosystems for Dermal Delivery

The objective of the present investigation was to formulate solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) for improving the dermal delivery of a local anesthetic agent lidocaine (LID). SLN and NLC were characterized for particle size distribution, polydispersity index, entrapment efficiency, X-ray powder diffraction pattern (XRD), thermal behavior by differential scanning colorimeter (DSC) and surface morphology by transmission electron microscopy (TEM). LID-loaded SLN and NLC were formulated into hydrogels for topical application. The in vitro permeation profiles of LID SLN gel, LID NLC gel, and a marketed LID formulation (Xylocaine gel) were evaluated by using guinea pig skin. The in vivo efficacy of LID SLN gel, LID NLC gel, and a marketed LID formulation (Xylocaine gel) gel was evaluated on guinea pig using pinprick test. LID SLN showed a particle size of 78.1 nm with a polydispersity index of 0.556, whereas LID NLC showed a particle size of 72.8 nm with a polydispersity index of 0.463. The entrapment efficiency of LID in both SLN and NLC was 97% and 95.9%, respectively. The TEM studies revealed the almost spherical nature of LID SLN and NLC formulations. The XRD and DSC studies of LID SLN suggested amorphization of drug in the carrier system. The SLN formulation was stable with respect to particle size, polydispersity, and entrapment efficiency for 6 months at 40 degrees C/75% relative humidity (RH). Negligible leakage was observed for the NLC formulation when stored for 1 month at 40 degrees C/75% RH. In vitro permeation studies indicated that LID SLN gel and LID NLC gel significantly sustained the LID release compared to that of Xylocaine gel. The in vivo efficacy results supported the results of the in vitro permeation studies wherein the LID SLN gel and LID NLC gel resulted in fivefold and sixfold increase in duration of anesthesia, respectively, compared to that of Xylocaine gel.

Lipid nanoparticles for transdermal delivery of flurbiprofen: formulation, in vitro, ex vivo and in vivo studies

The aim of the study is to prepare aqueous dispersions of lipid nanoparticles – flurbiprofen solid lipid nanoparticles (FLUSLN) and flurbiprofen nanostructured lipid carriers (FLUNLC) by hot homogenization followed by sonication technique and then incorporated into the freshly prepared hydrogels for transdermal delivery. They are characterized for particle size, for all the formulations, more than 50% of the particles were below 300 nm after 90 days of storage at RT. DSC analyses were performed to characterize the state of drug and lipid modification. Shape and surface morphology were determined by TEM which revealed fairly spherical shape of the formulations. Further they were evaluated for in vitro drug release characteristics, rheological behaviour, pharmacokinetic and pharmacodynamic studies. The pharmacokinetics of flurbiprofen in rats following application of SLN gel (A1) and NLC gel (B1) for 24 h were evaluated. The Cmax of the B1 formulation was 38.67 ± 2.77 μg/ml, which was significantly higher than the A1 formulation (Cmax = 21.79 ± 2.96 μg/ml). The Cmax and AUC of the B1 formulation were 1.8 and 2.5 times higher than the A1 gel formulation respectively. The bioavailability of flurbiprofen with reference to oral administration was found to increase by 4.4 times when gel formulations were applied. Anti-inflammatory effect in the Carrageenan-induced paw edema in rat was significantly higher for B1 and A1 formulation than the orally administered flurbiprofen. Both the SLN and NLC dispersions and gels enriched with SLN and NLC possessed a sustained drug release over period of 24 h but the sustained effect was more pronounced with the SLN and NLC gel

Development of SLN and NLC Enriched Hydrogels for Transdermal Delivery of Nitrendipine: In Vitro and In Vivo Characteristics

The purpose of this research was to investigate novel particulate carrier systems such as solid lipid nanoparticles (SLN) and nanostructured lipid carrier (NLC) for transdermal delivery of nitrendipine (NDP). For this investigation, four different gel-forming agents were selected for hydrogel preparation. Aqueous dispersions of lipid nanoparticles made from trimyristin (TM) were prepared by hot homogenization technique followed by sonication and then incorporated into the freshly prepared hydrogels. The particle size was analyzed by photon correlation spectroscopy (PCS) using Malvern zetasizer, which shows that for all the tested formulations, more than 50% of the particles were below 250 nm after 90 days of storage at room temperature. DSC analysis was performed to characterize the state of drug and lipid modification. Shape and surface morphology were determined by scanning electron microscope (SEM) and transmission electron microscope (TEM), which revealed fairly spherical shape of the formulations. The antihypertensive activity of the gels in comparison with that of oral NDP was studied using desoxy corticosterone acetate (DOCA)-induced hypertensive rats. It was observed that both carbopol SLN (A1) and carbopol NLC (B1) gels significantly controlled hypertension from the first hour (p < .05). The developed gels increased the efficacy of NDP for the therapy of hypertension. Both the SLN and NLC dispersions and the gels enriched with SLN and NLC possessed a sustained drug release over a period of 24 h, but the sustained effect was more pronounced with the SLN and the NLC gel formulations. Further, they were evaluated for zeta potential, entrapment efficiency, in vitro release, ex vivo permeation, and skin irritation studies.

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.

Nanostructured lipid carrier (NLC) based gel of celecoxib

Nanostructured lipid carriers (NLC) based topical gel of celecoxib was formulated for the treatment of inflammation and allied conditions. NLC prepared by the microemulsion template technique were characterized by photon correlation spectroscopy for size and scanning electron micrograph (SEM) studies. Drug encapsulation efficiency was determined using Nanosep ® centrifugal device. The nanoparticulate dispersion was suitably gelled and assessed for in vitro release and in vitro skin permeation using rat skin. Efficacy of the NLC gel was established using a pharmacodynamic study, i.e., aerosil-induced rat paw edema model. The skin permeation and rat paw edema pharmacodynamic studies were carried out in comparison with a micellar gel which had the same composition as that of the NLC gel except for the solid lipid and oil. The NLC based gel described in this study showed faster onset and elicited prolonged activity until 24 h.

Evaluation of Indomethacin Percutaneous Absorption from Nanostructured Lipid Carriers (NLC): In Vitro and In Vivo Studies

The aim of this study was the evaluation, in vitro and in vivo, of indomethacin (IND) release through the skin from nanostructured lipid carriers (NLC). NLC were prepared by ultrasonication, and were characterized in order to determine drug content, and particle size; finally the NLC were processed to hydrogels (A and B). The IND release pattern from NLC hydrogels was evaluated in vitro, to determine its percutaneous absorption through excised human skin (stratum corneum and epidermis, SCE), and in vivo. To evaluate the in vivo IND release, two methods were employed: (1) the IND topical anti-inflammatory activity was determined at different timepoints after its cutaneous application; in this case, the UVB-induced erythema on healthy human volunteers, chosen as inflammatory model, was monitored by reflectance visible spectrophotometry; (2) the extent of IND absorption into human skin was performed by the tape-stripping technique. The in vitro percutaneous absorption studies showed lower fluxes of IND through SCE membranes from NLC hydrogels (A and B) in comparison to an aqueous dispersion (C) and a hydro-alcoholic gel (D) both containing free IND. The findings from the former in vivo method showed that the anti-inflammatory effect, following IND topical application, was more prolonged with IND-loaded NLC gel formulation (A) if compared to formulation C and D. The results from tape stripping technique confirmed the trend obtained by the former in vivo method and indicated that IND topical bioavailability in the stratum corneum varied substantially depending upon the formulations (A–D). © 2005 Wiley-Liss, Inc. and the American Pharmacists Association