Lipid‐Based Nano‐Delivery for Oral Administration of Poorly Water Soluble Drugs (PWSDs): Design, Optimization and in vitro Assessment

Currently, more than 90% of compounds identified are water insoluble and or poorly water soluble, which is a bottle neck in the development of many new drug candidates. These poorly soluble drug molecules are difficult to formulate using conventional approaches and are associated with numerous formulation‐related performance issues. Formulating these compounds using lipid‐based systems is one of the rapidly growing interests and suitable drug delivery strategies. Lipid formulations such as self‐emulsifying/microemulsifying/nanoemulsifying drug delivery systems (SEDDS/SMEDDS/SNEDDS) have been attempted in many researches to improve the bioavailability and dissolution rate for their better dispersion properties. One of the greatest advantages of incorporating the poorly soluble drug into such formulation products is their spontaneous emulsion and or microemulsion/nanoemulsion formation in aqueous media. The performance and ongoing advances in manufacturing technologies have rapidly introduced lipid‐based drug formulations as commercial products into the marketplace with several others in clinical development. The current chapter aims to present the characteristics feature, development and utilization of oral lipid‐based nanoformulations within the drug delivery regime. The content of the chapter also provides an insight into the in vitro evaluation of lipid‐based nanosystems and their limitations

Acausal Modeling of Wind Turbines with Validation and Control Studies

This thesis involves the modeling, validation, and control studies of a Control-Oriented, Reconfigurable, and Acausal Floating Turbine Simulator (CRAFTS), that is currently under development. CRAFTS uses Modelica®, an object-oriented, declarative, multi-domain modeling language for physical system modeling in the Dymola environment. The CRAFTS simulator facilitates rapid dynamic simulation of wind turbines with various model variants and enables control co-design. A major emphasis of this thesis is in the validation of the CRAFTS simulator for a 15-MW land-based wind turbine through several test cases. These test cases were collaboratively developed in conjunction with other participating research entities. CRAFTS has undergone rigorous testing, with a particular emphasis on comparison against the industry standard OpenFAST platform (developed by the National Renewable Energy Lab (NREL)) as well as experimental data. Open loop testing scenarios scrutinize the wind turbine dynamic conditions such as varying rotor speed and pitching angle maneuvers. Diverse combinations of ramp and step commands have been employed to modulate rotor speeds and pitching angles. Validation results indicate very good agreement between CRAFTS and baseline results. CRAFTS was also tested under various types of closed-loop control scenarios, such as different types of wind profiles and various wind velocities. Wind types encompass stepped winds, wind gusts, steady winds, and sinusoidal wind patterns. In closed loop testing, firstly an industry standard controller ROSCO (also developed by NREL) was used. Thereafter, a nonlinear controller developed in our prior research was implemented and investigated. The closed loop performance of the CRAFTS model was compared with OpenFAST. The tests confirmed the validity of the CRAFTS model under closed-loop and also validated the nonlinear controller. The work was a critical element in the development of the CRAFTS simulator. Validation tests provided valuable insight into the accuracy of the underlying physics and often provided valuable feedback that led to model improvements. The work has laid the foundations for more advanced research, especially in the area of multivariable control design for floating offshore wind turbines

Dissolution improvement of solid self-emulsifying drug delivery systems of fenofibrate using an inorganic high surface adsorption material

Solidification of lipid formulations using adsorbents is a recent technique attracting great interest due to its favourable properties including flexibility in dose division, reduction of intra-subject and inter-subject variability, improvement in efficacy/safety profile and enhancement of physical/chemical stability. The current study aims to convert liquid self-emulsifying/nanoemulsifying drug delivery systems (SEDDS/SNEDDS) into solid SEDDS/SNEDDS and to assess how adsorption of the drug onto an inorganic high surface area material, Neusilin® grade US2 (NUS2), affects its in vitro dissolution performance. Lipid formulation classification systems (LFCS) Type III formulations were designed for the model anti-cholesterol drug fenofibrate. NUS2 was used to solidify the SEDDS/SNEDDS. Particle size and SEM analyses of solid SEDDS/SNEDDS powder were carried out to investigate the adsorption efficiency. In vitro dissolution studies were conducted to compare the developed formulations with the marketed product. The results of characterization studies showed that the use of 50 % (m/m) adsorbent resulted in superior flowability and kept the drug stable in amorphous state. Dissolution studies allow the conclusion that the formulation containing a surfactant of higher water solubility (particularly, Type IIIB SNEDDS) has comparably faster and higher release profiles than Type IIIA (SEDDS) and marketed product

Development and validation of a UPLC method for quantification of antiviral agent, Acyclovir in lipid-based formulations

AbstractPurposeThe objective of the current study is to evaluate the Ultra Performance Liquid Chromatography (UPLC) method for quantification of Acyclovir in lipid-based formulations.MethodA simple, rapid, reliable and precise reversed phase UPLC method has been developed and validated according to the regulatory guidelines, which composed of isocratic mobile phase; 0.25% formic acid (FA) in Milli-Q water with a flow rate of 0.5ml/min, and column BEH C18 (2.1×50mm, 1.7μm). The detection was carried out at 254nm.ResultsThe developed UPLC method was found to be rapid (1.2min run time), selective with well resoluted Acyclovir peak (0.89min) from different lipid matrices and sensitive (Limit of Detection (LOD) was 0.3ppm and Lower Limit of Quantification (LLOQ) was 1ppm). The accuracy and precision were determined and were perfectly matching with the standard FDA limits.ConclusionThe study showed that the proposed UPLC method can be used for the assessment of drug purity, stability, solubility and lipid-formulation release profile with no interference of excipients or related substances of active pharmaceutical ingredient

Optimization of self-nanoemulsifying formulations for weakly basic lipophilic drugs: role of acidification and experimental design

Formulators face great challenges in adopting systematic approaches for designing self-nanoemulsifying formulations (SNEFs) for different drug categories. In this study, we aimed to build-up an advanced SNEF development framework for weakly basic lipophilic drugs, such as cinnarizine (CN). First, the influence of formulation acidification on CN solubility was investigated. Second, formulation self-emulsification in media with different pH was assessed. Experimentally designed phase diagrams were also utilized for advanced optimization of CN-SNEF. Finally, the optimized formulation was examined using cross polarizing light microscopy for the presence of liquid crystals. CN solubility was significantly enhanced upon external and internal acidification. Among the various fatty acids, oleic acid-based formulations showed superior self-emulsification in all the tested media. Surprisingly, formulation turbidity and droplet size significantly decreased upon equilibration with CN. The design was validated using oleic acid/Imwitor308/Cremophor El (25/25/50), which showed excellent self-nanoemulsification, 43-nm droplet size (for CN-equilibrated formulations), and 88 mg/g CN solubility. In contrast to CN-free formulations, CN-loaded SNEF presented lamellar liquid crystals upon 50% aqueous dilution. These findings confirmed that CN-SNEF efficiency was greatly enhanced upon drug incorporation. The adopted strategy offers fast and accurate development of SNEFs and could be extrapolated for other weakly basic lipophilic drugs

Stability assessment of cinnarizine in self-emulsifying drug delivery systems

The current study was designed to evaluate the chemical and physical stability of cinnarizine within self-emulsifying drug delivery systems. According to International Conference of Harmonization guidelines, the selected formulations were enrolled into both accelerated and long-term stability studies up to 6 and 12 months, respectively. The chemical stability of the formulations was assessed periodically based on the intact cinnarizine level. The physical stability was evaluated based on the physical appearance and color change pattern of the formulations. The accelerated stability study revealed significant cinnarizine degradation in all the tested formulations at 3 and 6 months. All the tested formulations experienced sharp discoloration within 6 months of storage. On the other hand, the long-term stability study showed no significant cinnarizine degradation or color change within the formulations containing 100 % saturated medium chain glycerides (as oil component). While, the formulations containing 50 % unsaturated long chain fatty acids showed considerable drug degradation as well as significant discoloration. Accordingly, The formulations containing 100 % saturated medium chain glycerides provide excellent chemical and physical stability pattern and have the potential to provide a stable dosage form of cinnarizine.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Role of Alternative Lipid Excipients in the Design of Self-Nanoemulsifying Formulations for Fenofibrate: Characterization, in vitro Dispersion, Digestion and ex vivo Gut Permeation Studies

Background: The choice of lipid excipients and their origin are crucial determinant factors in the design of self-nanoemulsifying drug delivery system (SNEDDS).Aim: To investigate the aspects of alternative excipients which can influence the development of efficient SNEDDS and determine the fate of fenofibrate in aqueous media.Methods: SNEDDS of two groups (a and b) were developed using Cremercoor MCT/Capmul MCM and Kollisolv MCT/Imwitor 742 blended oils and water soluble surfactants (to improve lipid polarity) for the model anti-cholesterol drug fenofibrate. Visual assessment was employed and droplet size measurement was taken into initial consideration for optimized SNEDDS. Further SNEDDS optimizations were done on the basis of maximum drug loading by equilibrium solubility studies and maximum solubilized drug upon aqueous dispersion by dynamic dispersion studies. In vitro lipolysis was examined under simulated Fed and Fasted conditions. Intestinal permeability study of the optimal SNEDDS formulation was compared with the raw fenofibrate dispersion using non- everted “intestinal sac technique.”Results: Initial characterization and solubility studies showed that mixed glycerides of Kollisolv MCT/Imwitor 742 (group b) containing formulations generated highly efficient SNEDDS as they are stable and produced lower nanodroplets with higher drug loading (group b) as compared to mixed glycerides of Cremercoor MCT/Capmul MCM (group a). In vitro dispersion and digestion studies confirmed that SNEDDS of group b (polar mixed glycerides) can retain high amount of drug (99% drug in solution for more than 24 h time) in dispersion media and have high recovery after digestion. The results from the permeability assessment confirmed that fenofibrate had 4.3-fold increase with F3b SNEDDS compared with the control.Conclusion: SNEDDS formulations containing alternative excipients (Kollisolv MCT/Imwitor 742 blend) could be a potential oral pharmaceutical product in taking anti-hyperlipidaemic agent fenofibrate to the systemic circulation as solubilized form

pH-Responsive Liposomes of Dioleoyl Phosphatidylethanolamine and Cholesteryl Hemisuccinate for the Enhanced Anticancer Efficacy of Cisplatin

The current study aimed to develop pH-responsive cisplatin-loaded liposomes (CDDP@PLs) via the thin film hydration method. Formulations with varied ratios of dioleoyl phosphatidylethanolamine (DOPE) to cholesteryl hemisuccinate (CHEMS) were investigated to obtain the optimal particle size, zeta potential, entrapment efficiency, in vitro release profile, and stability. The particle size of the CDDP@PLs was in the range of 153.2 ± 3.08-206.4 ± 2.26 nm, zeta potential was -17.8 ± 1.26 to -24.6 ± 1.72, and PDI displayed an acceptable size distribution. Transmission electron microscopy revealed a spherical shape with ~200 nm size. Fourier transform infrared spectroscopic analysis showed the physicochemical stability of CDDP@PLs, and differential scanning calorimetry analysis showed the loss of the crystalline nature of cisplatin in liposomes. In vitro release study of CDDP@PLs at pH 7.4 depicted the lower release rate of cisplatin (less than 40%), and at a pH of 6.5, an almost 65% release rate was achieved compared to the release rate at pH 5.5 (more than 80%) showing the tumor-specific drug release. The cytotoxicity study showed the improved cytotoxicity of CDDP@PLs compared to cisplatin solution in MDA-MB-231 and SK-OV-3 cell lines, and fluorescence microscopy also showed enhanced cellular internalization. The acute toxicity study showed the safety and biocompatibility of the developed carrier system for the potential delivery of chemotherapeutic agents. These studies suggest that CDDP@PLs could be utilized as an efficient delivery system for the enhancement of therapeutic efficacy and to minimize the side effects of chemotherapy by releasing cisplatin at the tumor site

Evaluation of Self-Nanoemulsifying Drug Delivery Systems (SNEDDS) for Poorly Water-Soluble Talinolol: Preparation, in vitro and in vivo Assessment

ObjectiveThe aim of this study was to investigate the in vitro and in vivo performance of self-nanoemulsifying drug delivery systems (SNEDDSs) of talinolol (TAL), a poorly water-soluble drug.MethodsSelf-nanoemulsifying drug delivery systems of TAL were prepared using various oils, non-ionic surfactants and/or water-soluble co-solvents and assessed visually/by droplet size measurement. Equilibrium solubility of TAL in the anhydrous and diluted SNEDDS was conducted to achieve the maximum drug loading. The in vitro dissolution experiments and human red blood cells (RBCs) toxicity test, ex vivo gut permeation studies, and bioavailability of SNEDDS in rats were studied to compare the representative formulations with marketed product Cordanum® 50 mg and raw drug.ResultsThe results from the characterization and solubility studies showed that SNEDDS formulations were stable with lower droplet sizes and higher TAL solubility. From the dissolution studies, it was found that the developed SNEDDS provided significantly higher rate of TAL release (>97% in 2.0 h) compared to raw TAL and marketed product Cordanum®. The RBC lysis test suggested negligible toxicity of the formulation to the cells. The ex vivo permeability assessment and in vivo pharmacokinetics study of a selected SNEDDS formulation (F6) showed about four-fold increase in permeability and 1.58-fold enhanced oral bioavailability of TAL in comparison to pure drug, respectively.ConclusionTalinolol loaded SNEDDS formulations could be a potential oral pharmaceutical product with high drug-loading capacity, improved drug dissolution, increased gut permeation, reduced/no human RBC toxicity, and enhanced oral bioavailability

Levocarnitine Improves AlCl3-Induced Spatial Working Memory Impairment in Swiss albino Mice

Background: Aluminum, a neurotoxic substance, causes oxidative stress induced-neurodegenerative diseases. Several lines of evidence suggest that levocarnitine has an antioxidant effect and also plays an important role in beta-oxidation of fatty acids. However, the role of levocarnitine in aluminum-induced neurotoxicity has not been well documented. Here we aimed to investigate the effect of levocarnitine on aluminum chloride (AlCl3)-induced oxidative stress and memory dysfunction.Methods: Male Swiss albino mice (n = 30) were treated with either control (saline) or AlCl3 or AlCl3 plus levocarnitine or levocarnitine or astaxanthin plus AlCl3 or astaxanthin alone. The spatial working memory was determined by radial arm maze (RAM). In addition, we measured the lipid peroxidation (MDA), glutathione (GSH), advanced oxidation of protein products (AOPP), nitric oxide (NO) and activity of superoxide dismutase (SOD) in the various brain regions including prefrontal cortex (PFC), striatum (ST), parietal cortex (PC), hippocampus (HIP) hypothalamus (HT) and cerebellum (CB). We used astaxanthin as a standard antioxidant to compare the antioxidant activity of levocarnitine.Results: The RAM data showed that AlCl3 treatment (50 mg/kg) for 2 weeks resulted in a significant deficit in spatial learning in mice. Moreover, aluminum exposure significantly (p < 0.05) increased the level of oxidative stress markers such as MDA, GSH, AOPP and NO in the various brain regions compared to the controls. In addition, combined administration of levocarnitine and AlCl3 significantly (p < 0.05) lowered the MDA, AOPP, GSH and NO levels in mice.Conclusion: Our results demonstrate that levocarnitine could serve as a potential therapeutic agent in the treatment of oxidative stress associated diseases as well as in memory impairment