Properties of rapamycin solid lipid nanoparticles for lymphatic access through the lungs & part I: the effect of size

Nanomedicine ◽  
2020 ◽  
Vol 15 (20) ◽  
pp. 1927-1945
Author(s):  
Emelie Landh ◽  
Lyn M Moir ◽  
Peta Bradbury ◽  
Daniela Traini ◽  
Paul M Young ◽  
...  

Background: Lymphangioleiomyomatosis (LAM) is characterized by growth of smooth muscle-like cells in the lungs that spread to other organs via lymphatic vessels. Current oral rapamycin treatment is limited by low bioavailability of approximately 15%. Aim: The effect of inhaled rapamycin solid lipid nanoparticles (Rapa-SLNs) size on its penetration through the lymphatics. Method: Three Rapa-SLN formulations (200–1000 nm) were produced and assessed for particle characteristics and further for toxicity and performance in vitro. Results: Rapa-SLNs of 200 nm inhibited proliferation in TSC2-negative mouse embryonic fibroblast cells and penetrated the respiratory epithelium and lymphatic endothelium significantly faster compared with free rapamycin and larger Rapa-SLNs. Conclusion: Rapa-SLN approximately 200 nm allows efficient entry of rapamycin into the lymphatic system and is therefore a promising treatment for LAM patients.

Nanomedicine ◽  
2020 ◽  
Vol 15 (20) ◽  
pp. 1947-1963
Author(s):  
Emelie Landh ◽  
Lyn M Moir ◽  
Daniela Traini ◽  
Paul M Young ◽  
Hui X Ong

Aim: Lymphangioleiomyomatosis is characterized by smooth muscle-like cells in the lungs that spread to other organs via lymphatic vessels. Oral rapamycin is restricted by low bioavailability approximately 15%. The aim of the present study is to systematically investigate the effect of inhaled rapamycin solid lipid nanoparticles (Rapa-SLN) surface charge on efficacy and penetration into the lymphatics. Materials & methods: Rapa-SLN formulations with different charge: neutral, positive and negative, were produced and assessed for their physicochemical particle characteristics and efficacy in vitro. Results: Negative Rapa-SLNs were significantly faster at entering the lymphatic endothelium and more potent at inhibiting lymphanigiogenesis compared with neutral and positive Rapa-SLNs. Conclusion: Negative Rapa-SLNs showed efficient lymphatic access and should therefore be investigated further as a treatment for targeting extrapulmonary lymphangioleiomyomatosis.


Author(s):  
Pravin Patil ◽  
Anil Sharma ◽  
Subhash Dadarwal ◽  
Vijay Sharma

The objective of present investigation was to enhance brain penetration of Lamivudine, one of the most widely used drugs for the treatment of AIDS. This was achieved through incorporating the drug into solid lipid nanoparticles (SLN) prepared by using emulsion solvent diffusion technique. The formulations were characterized for surface morphology, size and size distribution, percent drug entrapment and drug release. The optimum rotation speed, resulting into better drug entrapment and percent yield, was in the range of 1000-1250 r/min. In vitro cumulative % drug release from optimized SLN formulation was found 40-50 % in PBS (pH-7.4) and SGF (pH-1.2) respectively for 10 h. After 24 h more than 65 % of the drug was released from all formulations in both mediums meeting the requirement for drug delivery for prolong period of time.


Author(s):  
V K Verma ◽  
Ram A

 Solid lipid nanoparticles (SLNs) of piroxicam where produced by solvent emulsification diffusion method in a solvent saturated system. The SLNs where composed of tripamitin lipid, polyvinyl alcohol (PVAL) stabilizer, and solvent ethyl acetate. All the formulation were subjected to particle size analysis, zeta potential, drug entrapment efficiency, percent drug loading determination and in-vitro release studies. The SLNs formed were nano-size range with maximum entrapment efficiency. Formulation with 435nm in particle size and 85% drug entrapment was subjected to scanning electron microscopy (SEM) and transmission electron microscopy (TEM) for surface morphology, differential scanning calorimetry (DSC) for thermal analysis and short term stability studies. SEM and TEM confirm that the SLNs are nanometric size and circular in shape. The drug release behavior from SLNs suspension exhibited biphasic pattern with an initial burst and prolong release over 24 h. 


Author(s):  
Rajkumar Aland ◽  
Ganesan M ◽  
P. Rajeswara Rao ◽  
Bhikshapathi D. V. R. N.

The main objective for this investigation is to develop and optimize the solid lipid nanoparticles formulation of acitretin for the effective drug delivery. Acitretin loaded SLNs were prepared by hot homogenization followed by the ultrasonication using Taguchi’s orthogonal array with eight parameters that could affect the particle size and entrapment efficiency. Based on the results from the analyses of the responses obtained from Taguchi design, three different independent variables including surfactant concentration (%), lipid to drug ratio (w/w) and sonication time (s) were selected for further investigation using central composite design. The  lipid Dynasan-116, surfactant poloxomer-188 and co surfactant egg lecithin resulted in better percent drug loading and evaluated for particle size, zeta potential, drug entrapment efficiency, in vitro drug release and stability. All parameters were found to be in an acceptable range. TEM analysis has demonstrated the presence of individual nanoparticles in spherical shape and the results were compatible with particle size measurements.  In vitro drug release of optimized SLN formulation (F2) was found to be 95.63 ± 1.52%, whereas pure drug release was 30.12 after 60 min and the major mechanism of drug release follows first order kinetics release data for optimized formulation (F2) with non-Fickian (anomalous) with a strong correlation coefficient (R2 = 0.94572) of Korsemeyer-Peppas model. The total drug content of acitretin gel formulation was found to 99.86 ± 0.012% and the diameter of gel formulation was 6.9 ± 0.021 cm and that of marketed gel was found to be 5.7 ± 0.06 cm, indicating better spreadability of SLN based gel formulation. The viscosity of gel formulation at 5 rpm was found to be 6.1 x 103 ± 0.4 x 103 cp. The release rate (flux) of acitretin across the membrane and excised skin differs significantly, which indicates about the barrier properties of skin. The flux value for SLN based gel formulation (182.754 ± 3.126 μg cm−2 h−1) was found to be higher than that for marketed gel (122.345 ± 4.786 μg cm−2 h−1). The higher flux and Kp values of SLN based gel suggest that it might be able to enter the skin easily as compared with marketed gel with an advantage of low interfacial tension of the emulsifier film that ensures an excellent contact to the skin. This topically oriented SLN based gel formulation could be useful in providing site-specific dermal treatment of psoriasis


2013 ◽  
Vol 10 (6) ◽  
pp. 656-666 ◽  
Author(s):  
Sandipan Dasgupta ◽  
Surajit Ghosh ◽  
Subhabrata Ray ◽  
Bhaskar Mazumder

2020 ◽  
Vol 8 (6) ◽  
pp. 495-510
Author(s):  
Manoj Kumar ◽  
Garima Sharma ◽  
Dinesh Singla ◽  
Sukhjeet Singh ◽  
Vandita Kakkar ◽  
...  

Background:: All-trans retinoic acid (ATRA) is widely employed in the treatment of various proliferative and inflammatory diseases. However, its therapeutic efficacy is imperiled due to its poor solubility and stability. Latter was surmounted by its incorporation into a solid matrix of lipidic nanoparticles (SLNs). Methods:: ATRA loaded SLNs (ATRA-SLNs) were prepared using a novel microemulsification technique (USPTO 9907758) and an optimal composition and were characterized in terms of morphology, differential scanning calorimetry (DSC), and powder X-ray diffraction studies (PXRD). In vitro release, oral plasma pharmacokinetics (in rats) and stability studies were also done. Results:: Rod-shaped ATRA-SLNs could successfully incorporate 3.7 mg/mL of ATRA, increasing its solubility (from 4.7 μg/mL) by 787 times, having an average particle size of 131.30 ± 5.0 nm and polydispersibility of 0.283. PXRD, DSC, and FTIR studies confirmed the formation of SLNs. Assay/total drug content and entrapment efficiency of ATRA-SLNs was 92.50 ± 2.10% and 84.60 ± 3.20% (n=6), respectively, which was maintained even on storage for one year under refrigerated conditions as an aqueous dispersion. In vitro release in 0.01 M phosphate buffer (pH 7.4) with 3% tween 80 was extended 12 times from 2h for free ATRA to 24 h for ATRA-SLNs depicting Korsmeyer Peppas release. Oral administration in rats showed 35.03 times enhanced bioavailability for ATRA-SLNs. Conclusion:: Present work reports preparation and evaluation of bioenhanced ATRA-SLNs containing a high concentration of ATRA (>15 times than that reported by others). Latter is attributed to the novel preparation process and intelligent selection of components. Lay Summary: All-trans retinoic acid (ATRA) shows an array of pharmacological activities but its efficacy is limited due to poor solubility, stability and side effects. In present study its solubility and efficacy is improved by 787 and 35.5 times, respectively upon incorporation into solid lipid nanoparticles (ATRA-SLNs). Latter extended its release by 12 times and provided stability for at least a year under refrigeration. A controlled and sustained release will reduce dose related side effects. ATRA-SLNs reported presently can thus be used in treatment /prophylaxis of disorders like cancers, tuberculosis, age related macular degeneration and acne and as an immune-booster.


2019 ◽  
Vol 9 (1) ◽  
pp. 76-85 ◽  
Author(s):  
R. Nithya ◽  
K. Siram ◽  
R. Hariprasad ◽  
H. Rahman

Background: Paclitaxel (PTX) is a potent anticancer drug which is highly effective against several cancers. Solid lipid nanoparticles (SLNs) loaded with anticancer drugs can enhance its toxicity against tumor cells at low concentrations. Objective: To develop and characterize SLNs of PTX (PSLN) to enhance its toxicity against cancerous cells. Method: The solubility of PTX was screened in various lipids. Solid lipid nanoparticles of PTX (PSLN) were developed by hot homogenization method using Cutina HR and Gelucire 44/14 as lipid carriers and Solutol HS 15 as a surfactant. PSLNs were characterized for size, morphology, zeta potential, entrapment efficiency, physical state of the drug and in vitro release profile in 7.4 pH phosphate buffer saline (PBS). The ability of PTX to enhance toxicity towards cancerous cells was tested by performing cytoxicity assay in MCF7 cell line. Results: Solubility studies of PTX in lipids indicated better solubility when Cutina HR and Gelucire 44/14 were used. PSLNs were found to possess a neutral zeta potential with a size range of 155.4 ± 10.7 nm to 641.9 ± 4.2 nm. In vitro release studies showed a sustained release profile for PSLN over a period of 48 hours. SLNs loaded with PTX were found to be more toxic in killing MCF7 cells at a lower concentration than the free PTX.


2021 ◽  
Vol 14 (8) ◽  
pp. 711
Author(s):  
Cláudia Pina Costa ◽  
Sandra Barreiro ◽  
João Nuno Moreira ◽  
Renata Silva ◽  
Hugo Almeida ◽  
...  

The nasal route has been used for many years for the local treatment of nasal diseases. More recently, this route has been gaining momentum, due to the possibility of targeting the central nervous system (CNS) from the nasal cavity, avoiding the blood−brain barrier (BBB). In this area, the use of lipid nanoparticles, such as nanostructured lipid carriers (NLC) and solid lipid nanoparticles (SLN), in nasal formulations has shown promising outcomes on a wide array of indications such as brain diseases, including epilepsy, multiple sclerosis, Alzheimer’s disease, Parkinson’s disease and gliomas. Herein, the state of the art of the most recent literature available on in vitro studies with nasal formulations of lipid nanoparticles is discussed. Specific in vitro cell culture models are needed to assess the cytotoxicity of nasal formulations and to explore the underlying mechanism(s) of drug transport and absorption across the nasal mucosa. In addition, different studies with 3D nasal casts are reported, showing their ability to predict the drug deposition in the nasal cavity and evaluating the factors that interfere in this process, such as nasal cavity area, type of administration device and angle of application, inspiratory flow, presence of mucoadhesive agents, among others. Notwithstanding, they do not preclude the use of confirmatory in vivo studies, a significant impact on the 3R (replacement, reduction and refinement) principle within the scope of animal experiments is expected. The use of 3D nasal casts to test nasal formulations of lipid nanoparticles is still totally unexplored, to the authors best knowledge, thus constituting a wide open field of research.


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