Solubility, viscosity and rheological properties of water-soluble chitosan derivatives

An investigation and comparison of solubility, viscosity and rheological properties under neutral, acidic and alkaline conditions of water-soluble chitosan derivatives, viz. O-carboxymethyl chitosan, N,O-carboxymethyl chitosan, N-[(2-hydroxy-3-trimethylammonium)propyl] chitosanchloride and O-carboxymethyl-N-[(2-hydroxy-3-trimethylammonium)propyl] chitosan chloride, was undertaken

Green Microemulsions for Cosmetics

Green microemulsions are one of interesting product forms and morelikely to develop in cosmetics and cosmeceutical industries. Theoutstanding points of green microemulsions are the use of nanotechnologyin manufacturing and the use of biodegradablecomponents, resulting in products with friendly properties to theenvironment. This review article focuses on definition of microemulsions,the role of surfactants in microemulsions, methods ofdetermining suitable components in microemulsions, biodegradablesurfactants and formulations of green microemulsions for cosmeticusing with skin and hair.Keywords: green microemulsions, surfactants, cosmetic, skin, scalphai

THE ROLES OF CHANNELING AGENTS ON THE DRUG RELEASE FROM WAX MATRIX TABLETS PREPARED BY MELT GRANULATION

The study aimed to investigate the effect of the channeling agents and to explore the mechanisms by which they affect the drug release from wax matrix tablets.  The channeling agents were potato starch and icing sugar. The wax matrix tablet contained 4% w/w of chlorpheniramine maleate, a model drug. The matrix formers were carnauba wax, the mixtures of wax and potato starch or icing sugar with different weight ratio of wax: channeling agent, i.e., 1:1, 1:2, and 2:1. They were prepared by melt granulation and then compression into tablet. The in vitro drug release from the wax matrix tablets was studied using USP II (Paddle) method. Within 8 hours, only 22.26% of the drug released from the neat wax matrix tablet, whereas the drug release was significantly increased from tablets containing a channeling agent. The rate and the extent of the drug released increased linearly with the increasing amounts of potato starch. Unlike icing sugar, it had less effect on enhancing the drug release at concentrations of 33% and 50%, but at 67%, the dramatic increase of the drug release was attained. This discrepancy was attributed to the nature and different mechanisms of the two channeling agents on promoting the drug release. The SEM micrographs as well as the degree of water uptake and tablets erosion clearly demonstrated the roles of these two channeling agents on the drug release. The release profiles of the drug from all matrices followed Higuchi model showing the r2 of 0.97-0.99.Keywords: Carnauba wax; Chlorpheniramine maleate; Higuchi diffusion model;  Icing sugar; Melt granulation; Potato starch;Â

PHARMACOKINETICS AND BIOEQUIVALENCE STUDIES OF WARFARIN SODIUM 5 MILLIGRAMS TABLET IN HEALTY THAI SUBJECTS

Objective:  The present study aimed to evaluate the bioequivalence between the generic warfarin sodium tablet and a reference product when gave as equal labeled doses in healthy Thai subjects under fasting condition.Methods:  A randomized, open-label, single dose, two treatments, two periods, two sequences, crossover design between 5 mg of warfarin administration under fasting condition was conducted in 22 male and female healthy Thai subjects. Each subject was assigned randomly to receive a single oral dose of the test formulation or the reference formulation of 5 mg warfarin tablets. Study periods were separated by a 14-day washout period. Blood samples were collected at 0.0, 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 2.0, 2.5, 3.0, 4.0, 8.0, 12.0, 24.0, 36.0, 48.0 and 72.0 h after drug administration. A simple, sensitive and specific HPLC method was used for quantification of warfarin in plasma. Pharmacokinetic parameters were analyzed including Cmax, Tmax, t1/2 and AUC0-72h.Results:  Twenty subjects, selected randomly from healthy adult Thai subjects were enrolled, age of 22.5 + 3.1 years, weight, 59 + 6 kg. Twenty-one subjects completed both periods of the study. The mean Cmax values were 759.63 and 778.20 ng/ml and the mean AUC0-72h were 20010.89 and 20418.55 ng. h./ml for test and reference formulations, respectively. The mean ratios for log-transformed data were 0.9955 and 0.9971 for Cmax, and AUC0-72h, respectively. The 90% confidence intervals of the ratios of Cmax and AUC0-72h between test and reference tablets were 88.23% – 105.70% and 94.40% – 99.61%.Conclusion:  It can be concluded that test and reference warfarin 5 mg products were bioequivalent in terms of rate and extent of absorption.Â

Characterization and chemical composition of epicuticular wax from banana leaves grown in Northern Thailand

This study aimed to investigate the physicochemical properties and chemical composition of epicuticular wax extracted from leaves of Kluai Namwa, a banana cultivar which is widely grown in Northern Thailand. Its genotype was identified by a botanist. The wax was extracted using solvent extraction. The fatty acid profiles and physicochemical properties of the wax namely melting point, congealing point, crystal structures and polymorphism, hardness, color, and solubility were examined and compared to those of beeswax, carnauba wax and paraffin wax. The results showed that the genotype of Kluai Namwa was Musa acuminata X M. balbisiana (ABB group) cv. Pisang Awak. The highest amount of wax extracted was 274 μg/cm2 surface area. The fatty acid composition and the physicochemical properties of the wax were similar to those of carnauba wax. It could be suggested that the banana wax could be used as a replacement for carnauba wax in various utilizing areas

Determination of galantamine in human plasma by LC-MS/MS using carbamazepine as an internal standard: Method validation and application to a pharmacokinetic study of galantamine hydrobromide prolonged-release capsules in healthy Thai volunteers

A rapid, sensitive and reliable LC-MS/MS method for the determination of galantamine in plasma was developed and validated for the pharmacokinetic study of galantamine hydrobromide 8 mg prolonged-release capsules. The plasma sample was prepared by simple liquid-liquid extraction with dichloromethane. Chromatographic separation was performed on a Hypurity C4 (150 x 4.6 mm, particle size 5.0 µm) using isocratic acetonitrile: 10 mM ammonium formate (90:10) as a mobile phase at a flow rate of 0.8 mL/min. Galantamine was detected by mass spectrometry using the electrospray ion source in the selected reaction monitoring mode. Carbamazepine was used as an internal standard (IS). The extraction recovery was 105.45–111.84% for galantamine and 107.35% for IS. Linearity was found within the calibration range of 0.39–62.5 ng/mL. The intra-day and inter-day accuracy were achieved with the mean concentrations of the quality control samples as 91.92–100.97% and 94.29–102.07%, respectively. The intra-day and inter-day precision were expressed as %CV of 1.34–6.11% and 3.31–5.01%. The long-term stability study showed that galantamine was stabled in plasma for at least 50 days at −30°C. This validated method was proven to be useful for the pharmacokinetic study of galantamine hydrobromide in healthy Thai volunteers. After the oral administration of one tablet in fasting conditions, Tmax and Cmax were found to be 5.61 ± 1.71 hours and 25.96 ± 4.18 ng/mL, respectively, whereas T1/2 was found to be 9.89 ± 1.48 hours

The Bioavailability and Pharmacokinetics of Silymarin SMEDDS Formulation Study in Healthy Thai Volunteers

The present study aimed to determine the pharmacokinetic parameters and bioavailability of silymarin 140 mg SMEDDS formulation. An open-label, single-dose pharmacokinetic study was conducted. Twelve healthy volunteers were included in the study. After the volunteers had fasted overnight for 10 h, a single-dose generic silymarin 140 mg SMEDDS soft capsule was administered. Then 10 ml blood samples were taken at 0.0, 0.25, 0.50, 0.75, 1.0, 1.33, 1.67, 2.0, 2.5, 3.0, 4.0, 6.0, 8.0, 10.0, and 12.0 h. The plasma silybin concentrations were analyzed using validated LC-MS/MS. The pharmacokinetic parameters were analyzed and calculated. The pharmacokinetic parameters were calculated after silymarin had been administered as a single capsule. The mean (range) Cmax was 812.43 (259.47–1505.47) ng/ml at 0.80 (0.25–1.67) h (tmax). The mean (range) AUC0-t and AUC0-inf were 658.80 (268.29–1045.01) ng.h/ml and 676.98 (274.10–1050.96) ng.h/ml, respectively. The mean ke and t1/2 were 0.5386 h-1 and 1.91 h, respectively. The silymarin SMEDDS formulation soft capsule showed rapid absorption and high oral bioavailability