Exploring the potential of natural polymers from plants as tablet binder and accessing their release profiles: A comparative analysis.

A tablet is a compact dosage form that includes both the active pharmaceutical ingredient (API) and various excipients, where a binder acts as an excipient, imparting cohesive quality in the powdered material. The present study aimed to extract polysaccharides from plant samples; Plantago ovata seeds, Plantago ovata husk, Lallemantia royleana, Ocimum basilicum and Acacia nilotica and to investigate their efficacy as tablet excipients. The wet granulation method was adopted for tablet formulation. Three different formulations (3%, 5% and 7%) were prepared by varying the binder concentration (hemicellulose extracted from plant samples). The tablets were evaluated by pre-compression tests; Angle of repose, bulk density, tapped density, Carr's Index, Hausner's ratio and post-compression tests; weight variation test, friability test, disintegration test, thickness test and dissolution test. Results were compared with binder commercially used in paracetamol drug. All 5% and 7% formulations showed friability and hardness values within range. Results of all the formulations of disintegration time are within range except 7% Plantago ovata seeds and 7% Plantago ovata husk. All the extracted hemicellulose showed good binding potential but, in all respects, the best formulation was 7% Lallemantia royleana, which has the potential to replace the synthetic binders in the pharmaceutical industry.

Preparation, characterization and biological evaluation of silver nanoparticles and drug loaded composites for wound dressings formed from Lallemantia royleana seeds' mucilage.

After an injury, the wounds need to be covered with a dressing. Lack of absorptive potential and sticking of dressing with the wound causes pain and slows the healing process. The aim of this study was to develop wound dressings having more absorptive potential and less sticking with the wound. The hemicelluloses from Lallemantia royleana seeds possess desirable properties for a wound dressing. The hemicellulose was blended with chitosan/chitin and glutaraldehyde to enhance the absorptive properties of the hemicellulose through cross-linking. Two types of formulations incorporating silver nanoparticles and ciprofloxacin were prepared. The composites were characterized by elemental analysis, Fourier-transform infrared spectroscopy and scanning electron microscopy, and evaluated for their antibacterial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). The dressings were subjected to in vivo studies on Albino rats. The dressings were found to be porous and the silver nanoparticles and drug particles were found to be uniformly distributed in the polymeric matrix. The composite containing ciprofloxacin released the drug in a sustained manner for 14-16 days. From extrapolation of the data, it was discovered that the formulation would release around 80% of ciprofloxacin in about two weeks. Silver-ciprofloxacin nano-composites exhibited comparable activity (zone of inhibition 19-30 mm) against E. coli to that of ciprofloxacin (standard, 21-35 mm) and relatively lower activity in case of S. aureus (zone of inhabitation 11-17 mm). The dressings did not stick to the wound site and the site remained wet during the healing process. Thus the use of hemicellulose from L. royleana seeds proved to be beneficial for preparing wound dressings with improved properties because of having high swelling index, porosity and spongy texture.

Grevillea robusta Delayed the Progression of Experimentally Induced Hepatic Fibrosis and Cirrhosis in Wistar Rats by Attenuating the Expression of Smooth Muscle Actin, Collagen, and TGF-ß.

The chronic damage to the liver causes fibrosis, especially when different proteins are accumulated in the liver, which is the basic characteristic of chronic liver damage. The excessive accumulation of the matrix protein such as collagen causes liver fibrosis. Liver fibrosis leads to cirrhosis, liver failure, and portal vein hypertension. Plants having antioxidants, free radical scavenging activities, and anti-inflammatory constituents are believed to be hepatoprotective in nature. Grevillea robusta (GR) is native to the subtropical environment. Its in vitro antioxidant, cytotoxic, and free radical scavenging activities are known, while the effect on liver fibrosis and cirrhosis remains elusive. The aim of this study was to evaluate the hepatoprotective and antifibrotic effects of Grevillea robusta plant. GR leaf extract (GREE) was prepared from the hydroethanolic extract (70%). Polyphenol and flavonoid contents and the in vitro antioxidant activity of the extract were determined. In vivo hepatitis was induced in Wistar rats by continual IP injections of CCl4. GREE was administered by oral gavage at a dose of 100, 300, and 500 mg/kg of body weight once daily for 4 weeks. Variations in rat's body weight, liver-to-body weight ratio, serum alanine aminotransferases, gamma-glutamyltransferase, liver histology, and cellular markers of liver fibrosis were evaluated. Serum levels of alanine aminotransferase (ALT) (p < 0.05) and gamma-glutamyltransferase (γ-GT) (p < 0.001) were decreased in the treatment group compared with the disease control group. RBC count was increased (p < 0.001) in the treatment group compared with the disease control group. The expression of alpha-SMA was downregulated to 40% (p < 0.05) and that of collagen was decreased by 9% (p < 0.05) compared with the disease control group. Extracellular matrix deposition and necrotic areas were also decreased as compared to the disease control group. It can be concluded that GR possesses hepatoprotective action by virtue of antioxidant constituents and delays the progression of liver cirrhosis by suppressing the activation of extracellular matrix-producing cells in the liver.

Synthesis of gold and silver nanoparticles by use of arabinoglucan from Lallemantia royleana.

Highly stable gold and silver nanoparticles were synthesized by use of an arabinoglucan from Lallemantia royleana seeds without additional use of reducing or stabilizing agents. The mechanism involved the reduction potential of the hemicellulose as verified by cyclic voltammetry. The arabinoglucan used was substantially free from ferulic acid and phenolic content, suggesting the inherent reducing potential of arabinoglucan for gold and silver ions. The synthesized nanoparticles exhibited surface plasmon resonance maxima at 515 nm (gold) and 397 nm (silver) corresponding to sizes of 10 nm and 8 nm, respectively. The zeta potential values were -24.1 mV (gold) and -22.3 mV (silver). The silver nanoparticles showed potential for application in surface-enhanced Raman spectroscopy. Gold nanoparticles were found to be non-toxic, whereas silver nanoparticles exhibited dose-dependent biological activities and found to be cytotoxic against brine shrimps and HeLa cell lines and the tumours caused by A. tumefaciens.

A structural study of Acacia nilotica and Acacia modesta gums.

Superficially similar carbohydrate polymers from similar sources can have dramatically different characteristics. This work seeks to examine the molecular properties responsible for these differences. Protons responsible for cross-polarization in the anomeric region of Acacia nilotica (AN) were replaced easily by deuterium, but not for Acacia modesta (AM). Time constants describing the mobility and cross-polarization transfer were both found to be lower for AM. Variable contact time experiments showed poorer fits and more heterogeneity for AN. Solution state HSQC experiments showed a lower number of environments in the anomeric region for AM. The relaxation time T2 of AM solutions had a lower value consistent with a higher viscosity. The Tg' of solutions were -14.5°C AN and -18.5°C AM. These results form a largely self-consistent picture of molecular differences between AN and AM, suggesting a more compact but heterogeneous structure for AN and more branching in the case of AM.

Thermal analysis of some natural polysaccharide materials by isoconversional method.

Isoconversional thermal analysis of some important polysaccharides from functional foods is reported. Various thermal parameters including apparent activation energy (Ea), pre-exponential factor (A) were worked out, and the fitness of data to different models describing the degradation kinetics of polysaccharides was studied. The polysaccharides from Mimosa pudica (MP), Plantago ovata (PO), Argyreia speciosa (AS), Acacia nilotica (AN), P. ovata husk (HK) and Acacia modesta (AM) exhibited multistep degradation while those from Astragalus gummifer (AG), Salvia aegyptiaca (SA) and Ocimum basicilicum (OB) degraded mainly in single step. Generally, the degradation was exothermal. The average Ea values as determined by Flynn-Wall-Ozawa method were found to be in the range 132-187 kJ mol(-1). The mean comprehensive index of thermal stability (ITS) fell in the range 0.33-0.43. All the materials under investigation except those from SA and AS appear to be as stable as some of the important commercial materials used as pharmaceutical ingredients. Model-fitting analysis revealed that the major degradation step follows first-order kinetics.

Kinetics and mechanism of thermal degradation of pentose- and hexose-based carbohydrate polymers.

This work aims at study of thermal degradation kinetics and mechanism of pentose- and hexose-based carbohydrate polymers isolated from Plantago ovata (PO), Salvia aegyptiaca (SA) and Ocimum basilicum (OB). The analysis was performed by isoconversional method. The materials exhibited mainly two-stage degradation. The weight loss at ambient-115°C characterized by low activation energy corresponds to loss of moisture. The kinetic triplets consisting of E, A and g(α) model of the materials were determined. The major degradation stage represents a loss of high boiling volatile components. This stage is exothermic in nature. Above 340°C complete degradation takes place leaving a residue of 10-15%. The master plots of g(α) function clearly differentiated the degradation mechanism of hexose-based OB and SA polymers and pentose-based PO polymer. The pentose-based carbohydrate polymer showed D(4) type and the hexose-based polymers showed A(4) type degradation mechanism.