Development and characterization of floating spheroids of atorvastatin calcium loaded NLC for enhancement of oral bioavailability

Polymeric Excipients in the Technology of Floating Drug Delivery Systems

The combination of targeted transport and improvement of the release profile of the active pharmaceutical ingredient (API) is a current trend in the development of oral medicinal products (MP). A well-known way to implement this concept is to obtain floating gastroretentive delivery systems that provide a long stay of the dosage form (DF) on the surface of the stomach contents. The nomenclature of excipients (Es) of a polymeric nature used in the technology of obtaining floating drug delivery systems (FDDS) is discussed. Based on the data presented in research papers, the most widely used groups of polymers, their properties, and their purpose in various technological approaches to achieving buoyancy have been determined. In addition, ways to modify the release of APIs in these systems and the Es used for this are described. The current trends in the use of polymers in the technology of floating dosage forms (FDF) and generalized conclusions about the prospects of this direction are outlined.

Lipid-Based Nano-Sized Cargos as a Promising Strategy in Bone Complications: A Review

Bone metastasis has been considered the fatal phase of cancers, which remains incurable and to be a challenge due to the non-availability of the ideal treatment strategy. Unlike bone cancer, bone metastasis involves the spreading of the tumor cells to the bones from different origins. Bone metastasis generally originates from breast and prostate cancers. The possibility of bone metastasis is highly attributable to its physiological milieu susceptible to tumor growth. The treatment of bone-related diseases has multiple complications, including bone breakage, reduced quality of life, spinal cord or nerve compression, and pain. However, anticancer active agents have failed to maintain desired therapeutic concentrations at the target site; hence, uptake of the drug takes place at a non-target site responsible for the toxicity at the cellular level. Interestingly, lipid-based drug delivery systems have become the center of interest for researchers, thanks to their biocompatible and bio-mimetic nature. These systems possess a great potential to improve precise bone targeting without affecting healthy tissues. The lipid nano-sized systems are not only limited to delivering active agents but also genes/peptide sequences/siRNA, bisphosphonates, etc. Additionally, lipid coating of inorganic nanomaterials such as calcium phosphate is an effective approach against uncontrollable rapid precipitation resulting in reduced colloidal stability and dispersity. This review summarizes the numerous aspects, including development, design, possible applications, challenges, and future perspective of lipid nano-transporters, namely liposomes, exosomes, solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC), and lipid nanoparticulate gels to treat bone metastasis and induce bone regeneration. Additionally, the economic suitability of these systems has been discussed and different alternatives have been discussed. All in all, through this review we will try to understand how far nanomedicine is from clinical and industrial applications in bone metastasis.

Nanostructured lipid carriers (NLCs) as drug delivery platform: Advances in formulation and delivery strategies

NLCs have provoked the incessant impulsion for the development of safe and valuable drug delivery systems owing to their exceptional physicochemical and then biocompatible characteristics. Throughout the earlier period, a lot of studies recounting NLCs based formulations have been noticeably increased. They are binary system which contains both solid and liquid lipids aiming to produce less ordered lipidic core. Their constituents particularly influence the physicochemical properties and effectiveness of the final product. NLCs can be fabricated by different techniques which are classified according to consumed energy. More utilization NLCs is essential due to overcome barriers surrounded by the technological procedure of lipid-based nanocarriers' formulation and increased information of the core mechanisms of their transport via various routes of administration. They can be used in different applications and by different routes such as oral, cutaneous, ocular and pulmonary. This review article seeks to present an overview on the existing situation of the art of NLCs for future clinics through exposition of their applications which shall foster their lucid use. The reported records evidently demonstrate the promise of NLCs for innovate therapeutic applications in the future.

Structured edible lipid-based particle systems for oral drug-delivery

Oral administration is the most popular and patient-compliant route for drug delivery, though it raises great challenges due to the involvement of the gastro-intestine (GI) system and the drug bioavailability. Drug bioavailability is directly related to its ability to dissolve, transport and/or absorb through the physiological environment. A great number of drugs are characterized with low water solubility due to their hydrophobic nature, thus limiting their oral bioavailability and clinical use. Therefore, new strategies aiming to provide a protective shell through the GI system and improve drug solubility and permeability in the intestine were developed to overcome this limitation. Lipid-based systems have been proposed as good candidates for such a task owing to their hydrophobic nature which allows high drug loading, drug micellization ability during intestinal digestion due to the lipid content, and the vehicle physical protective environment. The use of edible lipids with high biocompatibility paves the bench-to-bedside translation. Four main types of structured lipid-based drug delivery systems differing in the physical state of the lipid phase have been described in the literature, namely emulsions, solid lipid nanoparticles, nanostructured lipid carriers, and oleogel-based particles. The current review provides a comprehensive overview of the different structured edible lipid-based oral delivery systems investigated up to date and emphasizes the contribution of each system component to the delivery performance, and the oral delivery path of lipids.

Comprehensive Study of Atorvastatin Nanostructured Lipid Carriers through Multivariate Conceptualization and Optimization

The aim of the current study is to establish a comprehensive experimental design for the screening and optimization of Atorvastatin-loaded nanostructured lipid carriers (AT-NLCs). Initially, combined D-optimal screening design was applied to find the most significant factors affecting AT-NLCs properties. The studied variables included mixtures of solid and liquid lipids, the solid/liquid lipid ratio, surfactant type and concentration, homogenization speed as well as sonication time. Then, the variables homogenization speed (A), the ratio of solid lipid/liquid lipid (B), and concentration of the surfactant (C) were optimized using a central composite design. Particle size, polydispersity index, zeta potential, and entrapment efficiency were chosen as dependent responses. The optimized AT-NLCs demonstrated a nanometric size (83.80 ± 1.13 nm), Polydispersity Index (0.38 ± 0.02), surface charge (-29.65 ± 0.65 mV), and high drug incorporation (93.1 ± 0.04%). Fourier Transform Infrared Spectroscopy (FTIR) analysis showed no chemical interaction between Atorvastatin and the lipid mixture. Differential Scanning Calorimetry (DSC) analysis of the AT-NLCs suggested the transformation of Atorvastatin crystal into an amorphous state. Administration of the optimized AT-NLCs led to a significant reduction (p < 0.001) in serum levels of rats' total cholesterol, triglycerides, and low-density lipoproteins. This change was histologically validated by reducing the relevant steatosis of the liver.

Systematic Development of Bicalutamide Immediate Release Pellets Using Aeroperl and Non-MCC Extruder Aid

Background:

The Microcrystalline Cellulose is called as a gold standard for the manufacture of pellets. The poor disintegration leads to incomplete drug release that restricts the use of MCC in the immediate-release formulation.

Objective:

The present work aims to explore non-MCC extruder aid for pellet formulation and solubility modulation potential of Aeroperl® 300 Pharma.

Methods:

Bicalutamide (BCL) was selected as a model BCS class-II drug. The solubility of BCL was assessed in different vehicles such as polyethylene glycol, propylene glycol, and Tween by carrying out phase solubility study. The suitable vehicle was selected based on the higher solubility of BCL. The vehicle was further adsorbed on newer adsorbent Aeroperl® 300 Pharma to formulate liquisolid granules. The liquisolid granules were further incorporated into the pellet using mannitol and microcrystalline cellulose as an extruder aid. Box-Behnken design was adopted for the optimization of formulation considering MCC: mannitol ratio, the concentration of HPMC and spheronizer speed as independent factors whereas drug release at 30 min, disintegration time and aspect ratio were selected as dependent variables. The pellets were evaluated for different evaluation parameters.

Results:

Propylene glycol was selected for the formulation of liquisolid technique based on the results of the phase solubility study. Propylene glycol containing BCL was adsorbed on Aeroperl 300 Pharma. The optimized batch was selected exploring the Design-Expert software by considering the limits of different responses. Pellet had excellent flowability. Friability was found to be within the range (<1%). Pellets were found to be spherical and had pores on the surfaces.

Conclusion:

Liquisolid granules containing newer solubilizer Aeroperl was found to be a promising approach for the improvement in the solubility of the drug. The use of mannitol with MCC has a profound effect on disintegration time, without altering flow property and other parameters. No patents were reported on the combination of Bicalutamide, mannitol and Aeroperl. The critical finding of the present work is to use mannitol as an extruder aid to fasten the disintegration leads to complete drug release within a short period of time. Aeroperl and Mannitol, MCC: mannitol ratio, the concentration of HPMC and spheronizer speed were found to be significant and had the potential effect in pellet formulation.

Development and characterization of spheroidal antidiabetic polyherbal formulation from fresh vegetable juice: A novel approach

Polyherbal Formulations (PHF) were developed by combining fruit juices of Momordica charantia, Cucumis sativus, and Solanum lycopersicum in different ratios and optimized through Oral Glucose Tolerance Test (OGTT) model. PHF-C pretreated rats showed the highest reduction of Serum Glucose Levels (SGL) after 60 min of glucose administration. PHF-C was incorporated into spheroids using fresh juice (FJS) and lyophilized powder (LPS) of selected plants. In OGTT study, LPS showed a significant reduction of SGL. LPS was characterized as almost spherical, having disintegration time 8 min, adequate friability, and good flow properties. In STZ-induced diabetic rats on 7th, 14th, and 21st days, LPS was reduced SGL by 9.01%, 20.9%, 38.9% (250 mg/kg dose); 20.5%, 33.9%, and 50.7% (500 mg/kg dose), respectively. LPS showed a significant improvement in abnormal body weight, biochemical, and oxidative parameters in comparison to PHF-C and metformin. Novel formulation LPS (500 mg/kg) was found more effective (p < .05) in reversing STZ-induced hyperglycemia as compared to PHF-C (1,000 mg/kg) and at par with metformin (500 mg/kg). PRACTICAL APPLICATIONS: Fresh vegetable juice contains large quantities of vitamins and minerals. Cooking and processing of fruits may destroy their nutritional value. However, FJS also has some limitations, including seasonal specificity, patient compliance, less stability, loss of vitamins and fibers, abnormal sugar level, weak immunity, and difficult to carry by patients. Lyophilization is a well-known method to improve the physical state, shelf life, and stability of phytoconstituents. Poor absorption and less bioavailability also impede the acceptance of PHF. To overcome these limitations, a suitable novel drug delivery system is required which has high therapeutic efficacy and enhanced bioavailability. The patented spheroids of herbal extracts which are in use for the treatment of the number of diseases encouraged the present work. Spheroid protects the constituents of herbal drugs from gastric destruction and gut bacteria. The outcome of present research supports the concept of enhanced stability and bioavailability of phytoconstituents present in FJS.

Fabrication of chlorambucil loaded graphene- oxide nanocarrier and its application for improved antitumor activity

The present study aims at designing a biodegradable and biocompatible nanocarrier using gelatin and reduced graphene oxide nanosheets functionalized with folic acid, for release of chlorambucil drug in controlled manner and achieving high loading efficiency. From scanning electron microscopic studies small pore like structure with rough and thick morphology on the plane of graphene oxide is clearly visible indicating high loading of drug. Further, Drug loading and encapsulation efficiency, in vitro release studies of the drug from the nanocarrier at different concentrations of reduced graphene oxide, different pH were studied. The mean particle size, entrapment efficiency (%) of optimized folic acid functionalized gelatin-graphene oxide formulation was observed to be 300 nm and 56% respectively. From the release studies it is clear that, after 24 h the release rate of the drug was found to be higher at acidic conditions compared to neutral conditions. It was found that 62.1% and 82% of the total bound drug was released from the nanocarrier at pH 5.4 and pH 1.2 respectively. Besides, under neutral conditions (pH 7.4), 43.7% of the total bound drug was released from the nanocarrier in the first 24 h. The % cell viability of free drug, drug loaded nanocomposites against human cervical adenocarcinoma cell line was found to be 11.7% and 28% respectively at the dose of 500 μg mL^-1 after 24 h. IC50 values also manifest the significantly lower cytotoxicity of drug loaded nanocarrier (IC50 = 125.9 μg/mL) as compared to free-drug (IC50 = 86 μg/mL). For FAGGO, CLB and CLB-FAGGO the values of mean ± std. deviation were found to be 71.80 ± 6.66; 48.71 ± 23.15; 55.48 ± 19.65 respectively. The unique properties exhibited by biodegradable polymer like gelatin and carbon based materials such as graphene offers an excellent applications in biomedical field.

An update on polymer-lipid hybrid systems for improving oral drug delivery

INTRODUCTION

A promising approach that has recently emerged to overcome the complex biobarriers and interrelated challenges associated with oral drug absorption is to combine the benefits of polymeric and lipid-based nanocarriers within one hybrid system. This multifaceted formulation strategy has given rise to a plethora of polymer-lipid hybrid (PLH) systems with varying nanostructures and biological activities, all of which have demonstrated the ability to improve the biopharmaceutical performance of a wide range of challenging therapeutics.

AREAS COVERED

The multitude of polymers that can be combined with lipids to exert a synergistic effect for oral drug delivery have been identified, reviewed and critically evaluated. Specific focus is attributed to preclinical studies performed within the past 5 years that have elucidated the role and mechanism of the polymer phase in altering the oral absorption of encapsulated therapeutics.

EXPERT OPINION

The potential of PLH systems has been clearly identified; however, improved understanding of the structure-activity relationship between PLH systems and oral absorption is fundamental for translating this promising delivery approach into a clinically relevant formulation. Advancing research within this field to identify optimal polymer, lipid combinations and engineering conditions for specific therapeutics are therefore encouraged.

In vitro and in vivo evaluation of cyclodextrin-based nanosponges for enhancing oral bioavailability of atorvastatin calcium

The aim of this study was to explore the feasibility of complexing the poorly water-soluble drug atorvastatin calcium (AC) with β-cyclodextrin (β-CD) based nanosponges (NS), which offer advantages of improving dissolution rate and eventually oral bioavailability. Blank NS were fabricated at first by reacting β-CD with the cross-linker carbonyldiimidazole at different molar ratios (1:2, 1:4, and 1:8), then NS of highest solubilization extent for AC were complexed with AC. AC loaded NS (AC-NS) were characterized for various physicochemical properties. Pharmacokinetic, pharmacodynamics and histological finding of AC-NS were performed in rats. The prepared AC-NS showed particles size ranged from 408.7 ± 12.9 to 423 ± 15.9 nm while zeta potential values varied from -21.7 ± 0.90 to -22.7 ± 0.85 mV. The loading capacity varied from 17.9 ± 1.21 to 34.1 ± 1.16%. DSC, FT-IR, and PXRD studies confirmed the complexation of AC with NS and amorphous state of the drug in the complex. AC-NS displayed a biphasic release pattern with increase in the dissolution rate of AC as compared to plain AC. Oral administration of AC-NS (1:4 w/w, drug: NS) to rats led to 2.13-folds increase in the bioavailability as compared to AC suspension. Pharmacodynamics studies in rats with fatty liver revealed significant reduction (p < .05) in total cholesterol, triglyceride, LDL-C and increased level of beneficial HDL-C along with improvement in the associated liver steatosis as confirmed through photomicrographs of liver sections. In this study, we confirmed that complexation of AC with NS would be a viable approach for improving oral bioavailability and in vivo performance of AC.

The studies of PLGA nanoparticles loading atorvastatin calcium for oral administration in vitro and in vivo

A biodegradable poly(lactic-co-glycolic acid) loading atorvastatin calcium (AC) nanoparticles (AC-PLGA-NPs) were prepared by probe ultrasonication and evaporation method aiming at improving the oral bioavailability of AC. The effects of experimental parameters, including stabilizer species, stabilizer concentration and pH of aqueous phase, on particle size were also evaluated. The resultant nanoparticles were in spherical shape with an average diameter of 174.7 nm and a narrow particle size distribution. And the drug loading and encapsulation efficiency were about 8% and 71%, respectively. The particle size and polydispersion were almost unchanged in 10 days. The release curves of AC-PLGA-NPs in vitro displaying sustained release characteristics indicated that its release mechanisms were matrix erosion and diffusion. The pharmacokinetic study in vivo revealed that the C_max and AUC_0-∞ of AC-PLGA-NPs in rats were nearly 3.7-fold and 4.7-fold higher than that of pure atorvastatin calcium suspension. Our results demonstrated that the delivery of AC-PLGA-NPs could be a promising approach for the oral delivery of AC for enhanced bioavailability.