An Overview of Chemistry, Kinetics, Toxicity and Therapeutic Potential of Boldine in Neurological Disorders.

Boldine is an alkaloid obtained from the medicinal herb Peumus boldus (Mol.) (Chilean boldo tree; boldo) and belongs to the family Monimiaceae. It exhibits a wide range of pharmacological effects such as antioxidant, anticancer, hepatoprotective, neuroprotective, and anti-diabetic properties. There is a dearth of information regarding its pharmacokinetics and toxicity in addition to its potential pharmacological activity. Boldine belongs to the aporphine alkaloid class and possesses lipophilic properties which enable its efficient absorption and distribution throughout the body, including the central nervous system. It exhibits potent free radical scavenging activity, thereby reducing oxidative stress and preventing neuronal damage. Through a variety of neuroprotective mechanisms, including suppression of AChE and BuChE activity, blocking of connexin-43 hemichannels, pannexin 1 channel, reduction of NF-κß mediated interleukin release, and glutamate excitotoxicity which successfully reduces neuronal damage. These results point to its probable application in reducing neuroinflammation and oxidative stress in epilepsy, Alzheimer's disease (AD), and Parkinson's disease (PD). Moreover, its effects on serotonergic, dopaminergic, opioid, and cholinergic receptors were further investigated in order to determine its applicability for neurobehavioral dysfunctions. The article investigates the pharmacokinetics of boldine and reveals that it has a low oral bioavailability and a short half-life, requiring regular dosage to maintain therapeutic levels. The review studies boldine's potential therapeutic uses and mode of action while summarizing its neuroprotective benefits.  Given the favorable results for boldine as a potential neurotherapeutic drug in laboratory animals, more research is required. However, in order to optimise its therapeutic potential, it must be more bioavailable with fewer detrimental side effects.

Novel solvent-free gelucire extract of Plumbago zeylanica using non-everted rat intestinal sac method for improved therapeutic efficacy of plumbagin.

INTRODUCTION: Various shortcomings of the available methods of extraction of plumbagin from Plumbago zeylanica using non-edible organic solvents coupled with the poor aqueous solubility and low bioavailability called for extracting plumbagin in a water soluble form via a single step technique using hydrophilic lipid Gelucire 44/14. METHODS: Gelucire extract of P. zeylanica (GPZ) was prepared and evaluated for extraction efficiency, High-performance thin layer chromatography (HPTLC) and thermal analysis. In vitro intestinal absorption and bioavailability of plumbagin from GPZ in comparison with that of aqueous (APZ), ethanolic extract (EPZ) and standard plumbagin studied using non-everted rat intestinal sac model. RESULTS: The GPZ showed significantly higher extraction efficiency (3.24±0.12% w/w) compared to ethanolic (EPZ) and aqueous (APZ) extraction, 2.48±0.16% w/w and 0.07±0.02% w/w respectively. GPZ displayed significantly higher Q(30min) (cumulative percentage absorption of plumbagin in 30 min) and lower t(40%) (time required for 40% w/w drug absorption). The flux and apparent permeability coefficient in duodenum and ileum were 2, 3 and 6 fold higher than EPZ, standard plumbagin and APZ respectively. DISCUSSION: Improved therapeutic efficacy of plumbagin may be due to the micellar solubilization and consequent enhanced partitioning of plumbagin through intestinal by Gelucire which was reflected in the in vivo anti-inflammatory study conducted in rats. CONCLUSION: Thus extraction using Gelucire can be proclaimed as an efficient, economic and solvent-free technique for extraction of plumbagin and can be utilized for various clinically important water insoluble phytoconstituents in order to improve their biopharmaceutical properties.

Novel/conceptual floating pulsatile system using high internal phase emulsion based porous material intended for chronotherapy.

The aim of the present study was to design a novel/conceptual delivery system using ibuprofen, anticipated for chronotherapy in arthritis with porous material to overcome the formulation limits (multiple steps, polymers, excipients) and to optimize drug loading for a desired release profile suitable for in vitro investigations. The objective of this delivery system lies in the availability of maximum drug amount for absorption in the wee hours as recommended. Drug loading using 3(2) factorial design on porous carrier, synthesized by high internal phase emulsion technique using styrene and divinylbenzene, was done via solvent evaporation using methanol and dichloromethane. The system was evaluated in vitro for drug loading, encapsulation efficiency, and surface characterization by scanning electron, atomic force microscopy, and customized drug release study. This study examined critical parameters such as solvent volume, drug amount, and solvent polarity on investigations related to drug adsorption and release mostly favoring low-polarity solvent dichloromethane. Overall release in all batches ranged 0.98-52% in acidic medium and 71-94% in basic medium. These results exhibit uniqueness in achieving the least drug release of 0.98%, an ideal one, without using any release modifiers, making it distinct from other approaches/technologies for time and controlled release and for chronotherapy.

Modulation and optimization of drug release from uncoated low density porous carrier based delivery system.

The purpose of this research work was to explore an application of uncoated porous drug carrier prepared by single-step drug adsorption for a delivery system based on integration of floating and pulsatile principles intended for chronotherapy. This objective was achieved by utilizing 3(2) factorial design, solvent volume (X(1)) and drug amount (X(2)) as selected variables, for drug adsorption using solvents, methanol, and dichloromethane (DCM), of varying polarity. Nitrogen adsorption (N(2)), scanning electron microscopy of cross-sections, and atomic force microscopy were done to study adsorption patterns and their effect on release pattern. Drug release study was customized by performing for 6 h in acidic environment to mimic gastroretention followed by basic environment akin to transit phase. Correlation between porous data from mercury and N(2) adsorption was probably studied for the first time. Observed regression analysis values for pore volume, surface area, and drug release indicated the influence of selected variables. Total release range in acidic medium was 12.77-24.57% for methanol, 8.79-15.26% for DCM, and final release of 69.45-92.23% for methanol, and 60.16-99.99% for DCM influenced by varying internal geometries was observed. Present form of drug delivery system devoid of any additives/excipients influencing drug release shows distinct behavior from other approaches/technologies in chronotherapy by (a) observing desired low drug release (8%) in acidic medium, (b) overcoming the limitations of process variables caused by multiple formulation steps and different characteristic polymers, (c) reducing time consumption due to single step process, and (d) extending as controlled/extended release.

Effect of core and surface cross-linking on the entrapment of metronidazole in pectin beads.

The purpose of this study was to improve the entrapment efficiency of the water-soluble drug metronidazole using internal cross-linking agents. Calcium pectinate beads containing metronidazole were prepared by dropping a drug-pectin solution in 1% and 5% (m/V) calcium chloride for surface cross-linked beads. For the core cross-linked beads calcium carbonate was dispersed in the drug-pectin solution. The beads were characterized by particle size, swelling ratio, SEM, DSC, and in vitro drug release. It was found that the beads obtained by core cross-linking produced more drug entrapped beads than the surface cross-linked beads. Beads obtained using 1% (m/V) calcium chloride showed more drug entrapment than these obtained using 5% calcium chloride. The core cross-linking of pectin beads reduced drug loss by about 10-20%. The water lodging capacity of beads depended upon gel strength which is a function of the internal gelling agent and pectin concentration. Complete drug release was observed within 30-60 min in the acidic dissolution medium. This work has showed that the core cross-linking agent increases the water-soluble drug entrapment in calcium pectinate beads.

Development of hollow/porous calcium pectinate beads for floating-pulsatile drug delivery.

The purpose of this work was to develop hollow calcium pectinate beads for floating-pulsatile release of diclofenac sodium intended for chronopharmacotherapy. Floating pulsatile concept was applied to increase the gastric residence of the dosage form having lag phase followed by a burst release. To overcome limitations of various approaches for imparting buoyancy, hollow/porous beads were prepared by simple process of acid-base reaction during ionotropic crosslinking. The floating beads obtained were porous (34% porosity), hollow with bulk density<1 and had Ft50% of 14-24 h. In vivo studies by gamma scintigraphy determined on rabbits showed gastroretention of beads up to 5 h. The floating beads provided expected two-phase release pattern with initial lag time during floating in acidic medium followed by rapid pulse release in phosphate buffer. This approach suggested the use of hollow calcium pectinate microparticles as promising floating-pulsatile drug delivery system for site- and time-specific release of drugs acting as per chronotherapy of diseases.