Effect of liquid vehicles on the enhancement of rosmarinic acid and carvacrol release from oregano extract liquisolid compacts

New Perspectives about Relevant Natural Compounds for Current Dentistry Research

Natural compounds have been used since the earliest civilizations and remain, to this day, a safer alternative for treating various dental problems. These present antimicrobial, anti-inflammatory, antioxidant, analgesic, and antimutagenic effects, making them useful in the prophylactic and curative treatment of various oral diseases such as infections, gingivitis, periodontitis, and even cancer. Due to the high incidence of unpleasant adverse reactions to synthetic compounds, natural products tend to gradually replace conventional treatment, as they can be just as potent and cause fewer, milder adverse effects. Researchers use several methods to measure the effectiveness and safety profile of these compounds, and employing standard techniques also contributes to progress across all medical disciplines.

Andrographolide Liquisolid using Porous-Starch as the Adsorbent with Enhanced Oral Bioavailability in Rats

Andrographolide (AGL) is the major component of Andrographispaniculata. The poor water solubility and low dissolution strongly affect its oral absorption. Liquisolid technology has been used to improve its dissolution and oral bioavailability. Liquisolid powders of AGL (AGL-LS-PSG) were obtained by firstly dissolving AGL in the mixture of NMP, PEG 6000 and Soluplus®, and solidified by absorption of the blend in porous starch. Angle of repose, Carr index and Hauser ratio presented good powder fluidity and compressibility characteristics of AGL-LS-PSG. The results of optical microscopic observation, PXRD and DSC analysis indicated that AGL has been completely adsorbed in porous starch granules and existed in an amorphous or molecularly dispersing state. AGL-LS-PSG can obviously increase the drug dissolution rate compared to commercial guttate pills and raw drug. In vivo pharmacokinetic behavior of AGL-LS-PSG was investigated following a single oral administration to rats. The C_max (0.37 ± 0.06 μg mL^-1) and AUC_0-2h (13.55 ± 2.67 μg h mL^-1) of AGL-LS-PSG were evidently increased compared to commercial guttate pills (C_max = 0.30 ± 0.21 μg mL^-1, AUC_0-2h = 9.88 ± 3.57 μg h mL^-1). This study indicated great potential of liquisolid technology in effectively improving the dissolution and bioavailability of AGL.

Determination of the Phenolic Profile, and Evaluation of Biological Activities of Hydroethanolic Extract from Aerial Parts of Origanum compactum from Morocco

Origanum compactum belonging to the family Lamiaceae is widely used in food and pharmaceutical fields due to its biologically active substances. We aimed to investigate the total phenol and flavonoid contents and the phenolic composition, and to evaluate the antioxidant and antibacterial properties of hydroethanolic extract from of Origanum compactum. Total phenol and flavonoid contents were evaluated using gallic acid and quercetin as standards, respectively, and the phenolic profile was characterized using high-performance liquid chromatography coupled to a photodiode array and electrospray ionization mass spectrometry (HPLC-PDA-ESI/MS). The antioxidant activity was determined by two methods: ferric reducing power (FRAP) assay and the phosphomolybdate method. The antibacterial effect was evaluated against four bacteria (Escherichia coli, Salmonella typhimurium, Staphylococcus aureus and Listeria monocytogenes) using the broth microdilution method. The findings show that the total phenolic and flavonoid contents were 107.789 ± 5.39 mg GAE/g dm and 14,977 ± 0.79 mg QE/g dm, respectively. A total of sixteen phenolic compounds belonging to phenolic acids and flavonoids were detected. Furthermore, the extract showed strong antioxidant activity, and displayed a bacteriostatic effect against Escherichia coli and Salmonella typhimuriumn, and a bactericidal effect against Staphylococcus aureus and Listeria monocytogenes. Therefore, this study reveals that Origanum compactum extracts display potential as antibacterial and natural antioxidant agents for fighting against pathogenic bacteria and preventing oxidative stress.

Technology of Processing Plant Extracts Using an Aluminometasilicate Porous Carrier into a Solid Dosage Form

A method of preparing tablets called liquisolid technique is currently emerging. In these formulations, an important role is played by porous carriers, which are the basic building blocks of liquisolid systems (LSSs). The most common are microcrystalline cellulose (MCC), magnesium aluminometasilicates, silica aerogels, mesoporous silicates, clays, etc. In this study, magnesium aluminometasilicate is used to prepare modified LSS formulations with plant extracts as model drugs dissolved in water (W) or ethanol (E). The modification involves drying tablets in a microwave (MW) and hot air dryer (HA) for a specified period. Powder blends and tablets were evaluated for physical properties, and their antioxidant activity (AA) was measured in a modified dissolution by ferric reducing antioxidant power assay (FRAP). PLS and ANOVA were used to compare tablets properties depending on the composition and technology. The experiment is based on a previous one, in which the plant extracts were processed into tablets using a similar method. Therefore, extending the study to include more plants and the robust statistical evaluation and comparison of the products was a procedure to justify the suitability of the presented method for a wide range of liquid plant extracts. As a result, we obtained tablets with excellent physical properties, including a short disintegration and dissolution, which is problematic in tableted extracts.

Liquisolid systems as a novel approach in formulation and manufacturing of solid dosage forms: Challenges and perspectives

Liquisolid systems are a novel, promising platform for the production of solid dosage forms with a high liquid content, i.e. dispersion of the drug in a suitable, hydrophilic, non-volatile liquid vehicle or liquid drug. This technology requires conventional, but highly porous excipients (carrier and coating material in the appropriate ratio) able to absorb/adsorb liquid medication, resulting in both good flowability and acceptable compression properties. This approach has shown great potential to improve the dissolution rate and bioavailability of poorly soluble drugs, and has been recognized as a good alternative to common, more complex and expensive techniques. A variety of applications of this simple technique have been investigated recently, including the preparation of: modified release tablets, orally disintegrating tablets, solid dosage forms with liquid herbal extracts, etc. This emerging technology has numerous advantages, and the most important are: simplicity, cost-effectiveness, applicability in large scale production and environmental friendliness. However, it is accompanied by certain challenges as well, such as limited applicability in the case of highly dosed drugs. This article aims to give a comprehensive overview of recent progress regarding the potential applications of this technology, as well as to give an insight into the new liquisolid-based techniques intending to further support its commercial applicability.

Application of a liquisolid technique to cannabis sativa extract compacts: Effect of liquid vehicles on the dissolution enhancement and stability of cannabinoids

This work describes the application of liquisolid technique to enhance cannabinoid dissolution from Cannabis sativa L. (CS) compacts. Effects of five vehicles, namely, volatile (ethanol) and nonvolatile (caprylocaproyl macrogolglycerides, polyethylene glycol 400, oleoyl macrogolglycerides and polysorbate 20) liquids, on tablet properties, dissolution and stability were investigated. The viscid oleoresin CS extract was mixed with vehicles before being transformed into free-flowing powder by the use of microcrystalline cellulose and colloidal silica as carrier and coating materials. Liquid vehicles had a nonsignificant effect on liquid load factor of CS extract. CS liquisolid compacts had acceptable tableting properties in terms of weight variation, friability, hardness, content uniformity and disintegration time. Different vehicles affected the hardness, disintegration, and wettability of CS compacts and thus the dissolution behaviors of cannabinoids to different extents. Dissolutions of cannabinoids from CS compacts were rate-limited by the disintegration process. Liquisolid formulations using nonvolatile liquids with low polarity or high hydrophilic-lipophilic balance yielded more than 90% cannabinoid dissolution. Stability studies revealed nonsignificant changes in tablet characteristics, cannabinoid content and dissolutions of CS compacts when stored at 5 ± 3 °C for 3 months. This work presents a general concept of how to successfully formulate CS extract with cannabinoid dissolution enhancement characteristics.

An Investigation into the Influence of Process Parameters and Formulation Variables on Compaction Properties of Liquisolid Systems

Liquisolid technology, as a promising approach for bioavailability enhancement, has received increasing attention in recent years. However, literature reports addressing the challenges for its industrial application, particularly those related to compaction behavior of liquisolid systems, are scarce. The aim of this study was to investigate the influence of process parameters and formulation variables on the flowability, wetting, and compaction properties of the liquisolid systems prepared in a fluid bed processor. The experiments with microcrystalline cellulose, as a carrier, were performed according to 2³ full factorial design. The effects of liquid content, spray air pressure, and liquid feed rate on the properties of liquisolid systems were investigated. Liquisolid admixtures with microcrystalline cellulose were compared with those prepared with novel carriers, Fujicalin^® and Neusilin^® US2. "Out-die" Heckel, modified Walker, and Kuentz-Leuenberger models were used to analyze the compressibility of liquisolid admixtures. The results obtained showed that an increase in liquid content (in the range of 10 to 15%) led to a decrease in flowability of liquisolid admixtures with microcrystalline cellulose, as well as more pronounced influence of spraying conditions. On the other hand, higher liquid content led to higher compressibility. Fujicalin^® and Neusilin^® US2 liquisolid admixtures were found to have superior flowability and compressibility in comparison with those with microcrystalline cellulose, despite the considerably higher liquid load (50-55% liquid content in Neusilin^® US2 compacts). Acceptable compactibility of the investigated liquisolid systems was observed. The fluid bed processor was shown to be suitable equipment for production of liquisolid systems, but with careful adjustment of process parameters.

Cardioprotective Efficacy of Silymarin Liquisolid in Isoproterenol Prompted Myocardial Infarction in Rats

Myocardial infarction (MI) is the principal cause of death in many countries. Silymarin (SM) is a herbal antioxidant and can be efficiently used in preventing cardiovascular diseases (CVDs). The study is aimed to enhance the absorption rate and biological activity of SM by using liquisolids besides investigating the cardioprotective activity of SM and its selected liquisolid formula against isoproterenol prompted cardiotoxicity in rats. Eight formulae were prepared according to (2³) full-factorial design. The effect of viscosity increasing agent type and concentration, as well as the carrier/coat ratio on the dissolution rate and angle of repose were studied. All formulae were tested for content uniformity, micromeritic properties, dissolution performance besides the evaluation of its physicochemical properties, and scanning electron microscopy (SEM). Based on the factorial design outcomes, the highest desirability was obtained from F3 with excipient ratio value (R) of 20%, dissolution rate at Q_5 min of 26.9%, and angle of repose of 19. Oral administration of F3 liquisolid and SM revealed a significant protective efficacy against the modification of cardiac plasma markers, brain natriuretic peptide (BNP), interleukin-10 (IL-10), vascular endothelial growth factor (VEGF), and transforming growth factor (TGF)-β1 besides cardiac superoxide dismutase (SOD), malondialdehyde (MDA), and total protein kinase-1 (Akt-1) levels. Additionally, they minimized cardiac inducible nitric oxide synthase (iNOS), microRNA-34a (miR-34a), and p38 mitogen-activated protein kinase (p38-MAPK) levels. In conclusion, F3 liquisolid compact possessed an overall pronounced results over pure SM reckoned to its enhanced solubility and efficacy.

Application of liquisolid technology for promoting the renoprotective efficacy of walnut extracts in chronic renal failure rat model

Chronic renal failure (CRF) is among the major health problems that could lead to increased morbidity and mortality among population. 'Nutraceuticals' is an emerging field for natural agents from plant foods that could reduce the progression of such disease. Many newly developed drugs are having bioavailability problems owing to their water insolubility. Liquisolid technique is one of the promising technological approaches to increase solubility and hence, drug absorption. The aim of the present research is to prepare and evaluate the renoprotective effect of the walnut extracts liquisolid formulations in CRF rat model. Saturation solubility study claimed PEG 400 and Tween 20 as good solubilizers for walnut extracts, thus chosen for preparation. The angle of slide was determined for the carrier; microcrystalline cellulose and coating material; silicon dioxide and liquid load factor was evaluated. Eight liquisolid systems were prepared employing 25% and 50% of liquid medication. Their flow and compressibility parameters showed good properties. Dissolution study was more in favor of formulations prepared using PEG 400. Of these, formulation F8 comprising carrier/coat ratio (10:1) and 50% liquid medication, showing superior dissolution properties was selected to perform stability and in-vivo evaluations. Two CRF induced rat groups received F8 at two oral doses (50 and 100 mg/kg). Biochemical and nutritional parameters were compared with both normal and CRF control rats. Results showed improvement of renal function, oxidative stress, antioxidant and inflammatory biomarkers as well as increased appetite and body weight gain on administration of both doses of walnut liquisolid formulation, F8.