Formulation, characterization and optimization of hepatitis B surface antigen (HBsAg)-loaded chitosan microspheres for oral delivery.

CONTEXT: Approximately 400 million persons worldwide have chronic hepatitis B. This is due to problems associated with vaccine delivery, stability and cost. Hence the present challenge in vaccinology is to develop safer, cheaper and easy-to-deliver forms of vaccines. A novel needle-free oral vaccine will be an ideal tool to fight this silent killer disease. OBJECTIVE: The aim of this work was to prepare and evaluate chitosan-loaded HBsAg microspheres for oral delivery. MATERIALS AND METHODS: Chitosan microspheres were prepared by emulsion solvent evaporation technique. To overcome the enzymatic and permeation barrier, protease inhibitors and permeation enhancers were also added. Studies were conducted to find the effect of stabilizer concentration, stirring speed, cross-linking agent and polymer concentration on microsphere size and entrapment efficiency. Formulations were characterized for their particle size, entrapment efficiency. They were also evaluated for the in vitro drug release, in vivo performances and the effect of different storage conditions. RESULTS: HBsAg-loaded chitosan microspheres with bacitracin as protease inhibitor showed better protective levels of immunity after oral administration comparing with aprotinin as protease inhibitor. Stability at room temperature up to a period of four months reduces incomplete vaccine coverage and logistic requirements. CONCLUSION: The study signifies the potential of the formulated chitosan microspheres for effective oral administration of HBsAg.

A HPTLC densitometric method for the determination of aloeverose in Aloe vera gel.

Aloe vera gel is a familiar ingredient in a range of widely available and advertisement healthcare and cosmetic products. As to date there are no documented reports on the standardization of A. vera gel and the following study is an attempt in this direction. A. vera gel was evaluated for its aloeverose content for the first time. Aloeverose, was separated on a thin-layer of silica gel by isocratic gradient elution technique was determined by using HPTLC-photodensitometry. The proposed method is simple and sensitive and can be used for the routine assay of aloeverose in phytomedicines containing A. vera gel.

Curcuma zedoaria Rosc. (white turmeric): a review of its chemical, pharmacological and ethnomedicinal properties.

OBJECTIVES: Curcuma zedoaria Rosc is a perennial herb found in tropical countries, such as India, Japan and Thailand. Various parts of this plant are used in Ayurveda and other folk medicines for the treatment of different ailments such as diarrhoea, cancer, flatulence and dyspepsia. This study is an attempt to compile an up-to-date and comprehensive review of C. zedoaria that covers its traditional and folk medicinal uses, phytochemistry and pharmacology. KEY FINDINGS: Research carried out using different in-vitro and in-vivo techniques of biological evaluation supports most of the claims. SUMMARY: This review presents the botany, chemistry, traditional uses and pharmacological data of the plant.

Preparation and evaluation of fast-disintegrating effervescent tablets of glibenclamide.

Fast-dissolving effervescent tablets (FETs) were prepared by the modification of nonreactive liquid-based wet granulation technique. Effervescent systems are not stable in the presence of trace amount of moisture, and elimination or inactivation of free water is the key to stability apart from manufacturing in controlled humidity environment. Our main objective of the project was to develop FETs of glibenclamide based on highly plastic granules that can be compressed at low pressure to form fast-melting pharmaceutical tablets. In this study, we have screened various acid and carbonate sources for the effervescent system. Citric acid was coated with plastic materials such as polyethylene glycol (PEG), which provide a physical barrier to the reaction. The inherent hygroscopic nature of PEG could decrease the affinity for moisture of effervescent mixtures and can provide a stabilizing effect. Sodium bicarbonate was blended with sugar alcohol like mannitol, which would give a protective coating. PEG 1000 melts at body temperature (approximately 37 degrees C) and thereby does not delay the reaction between the acid source and base. The present formulation using citric acid-sodium bicarbonate and citric acid-sodium glycine carbonate tablet with PEG and mannitol was found to have better reaction properties and reaction stability than does the standard citric acid-sodium bicarbonate tablet. FETs of glibenclamide might aid in dissolution due to increase in microenvironmental pH around the granules and saliva. Sensory study on disintegration time and mouth feel attributes ranked the present formulation based on grittiness, chalkiness, and overall preference as best.

In vitro antioxidant studies on the benzyl tetra isoquinoline alkaloid berberine.

Berberine is a benzyl tetra isoquinoline alkaloid which is widely used as an antimicrobial and an antidiarrhoeal. As berberine containing plants are virtually used in all forms of traditional medicine, our study aimed to examine the antioxidant activity of berberine using 2,2-diphenyl 1-picrylhydrazyl (DPPH) radical scavenging, nitric oxide scavenging, lipid peroxidation, superoxide scavenging, iron chelating activity and 2,2-azino bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) radical scavenging methods. The IC(50) values for all the models were calculated by regression analysis. In all the models tested, berberine showed its ability to scavenge the free radicals in a concentration dependent manner. The present study thereby justifies the therapeutic potential of berberine.

Alcoholic stem extract of Coscinium fenestratum regulates carbohydrate metabolism and improves antioxidant status in streptozotocin-nicotinamide induced diabetic rats.

Alcoholic extract of the stems of Coscinium fenestratum, a medicinal plant indigenous to India and Sri Lanka used in ayurveda and siddha medicine for treating diabetes, was studied for its carbohydrate metabolism effect and antioxidant status in streptozotocin-nicotinamide induced type 2 diabetic rats. Oral administration of C. fenestratum stem extract in graded doses caused a significant increase in enzymatic antioxidants such as catalase, superoxide dismutase, glutathione synthetase, peroxidase, and glutathione peroxidase and in the nonenzymatic antioxidants ascorbic acid, ceruloplasmin and tocopherol. Effects of alcoholic extract on glycolytic enzymes such as glucose-6-phosphate dehydrogenase, lactate dehydrogenase and hexokinase showed a significant increase in their levels, whereas a significant decrease was observed in the levels of gluconeogenic enzyme, glucose-6-phosphatase and alanine aminotransferase in treated diabetic rats. Serum creatinine and urea levels also declined significantly. This investigation demonstrates significant antidiabetic activity of C. fenestratum.