Microwave-assisted extraction and content determination of astilbin in Lysiphyllum strychnifolium stems

Abstract Lysiphyllum strychnifolium (Craib) A. Schmitz. (in Thai name, Ya nang daeng) has been traditionally used to treat fever, alcohol intoxication, cancer, allergies, and blood toxins. It can be used as a health-promoting herbal tea and contains hydroalcoholic extracts. The purpose of the present study was to develop a microwave-assisted extraction method for astilbin in L. strychnifolium stems. HPLC was used to determine astilbin content. Three extraction conditions were optimized: types of solvent, microwave power levels, and the number of extraction cycles. Water:methanol (40:60) was the best solvent for astilbin extraction from L. strychnifolium stems using 450 watts and six microwave-assisted extraction cycles. This technique offers important advantages over conventional methods, such as shorter extraction times, substantial energy savings, and a reduced environmental burden.

Design and optimization of process parameters of polyvinyl alcohol-graft-lactic acid films for transdermal drug delivery.

The objective was to apply a simplex lattice design to determine the properties of polyvinyl alcohol-graft-lactic acid (PVA-g-LA) with different values for two independent variables: curing time (X1) and LA ratio (X2). Each independent variable was varied among three levels: -1, 0, and +1. Three coded levels were 120 min, 150 min, and 180 min for X1 and 2.5 g, 5 g, and 7.5 g for X2. Dependent variables of swelling behavior in various swelling media and thermal analysis parameters were monitored. The optimal formulation was selected based on the desirability value. The prediction was accurate, showing a low value of percent error. The morphology of the selected formulation with the highest desirability value showed a compact and dense film. Propranolol hydrochloride used as a model drug, was loaded into PVA-g-LA film. The propranolol hydrochloride content was 4.19 ± 1.05 mg/cm2. The cumulative release and permeation of drug were 61.94 ± 8.03% and 59.96 ± 6.61%, respectively. Thus, response surface methodology can be used as a tool to predict or optimize the process parameters for PVA-g-LA transdermal films in an accurate manner. PVA-g-LA could control the release and permeation of drug from the film layer.

Transdermal patches of lidocaine/aspirin ionic liquid drug-loaded gelatin/polyvinyl alcohol composite film prepared by freeze-thawed procedure.

The objectives of this study are to prepare a 5 wt% lidocaine/aspirin ionic liquid drug-loaded gelatin/polyvinyl alcohol composite film using a freeze-thaw procedure and to evaluate their physicochemical characteristics, in vitro drug release, and stability. Lidocaine/aspirin ionic liquid drugs can be prepared by an ion-pair reaction between the hydrochloride salts of lidocaine and the sodium salts of aspirin, which showed a significant change in their thermal properties when compared to those pure drugs. The results showed that a transdermal patch could feasibly be used in pharmaceutical transdermal patches with good physicochemical properties. A chemical interaction between the drug and polymer base was not found. Decomposition of the lidocaine/aspirin ionic liquid drug was found in the patch; however, the properties of the patch were not changed after drug loading. The patch controlled the drug release and showed good stability during the studied period of three months when kept at 4°C more than at ambient temperature and 45°C.

Optimal condition of cannabis maceration to obtain the high cannabidiol and Δ9-tetrahydrocannabinol content.

The aim of this work was to optimize a maceration condition of cannabis (Cannabis sativa L.). A circumscribed central composite experimental design was applied in this work. Temperature and time were varied from 40-80 °C and 30-90 min, respectively. The three responses (i.e., extraction yield, cannabidiol content, and Δ9- tetrahydrocannabinol content) were predicted by computer software. The yield was high when cannabis was macerated using ethanol at high temperature and long duration time. While cannabidiol and Δ9- tetrahydrocannabinol content was high when macerating at a low heating temperature and short duration time. The optimal condition provided the simultaneous high of cannabidiol and Δ9- tetrahydrocannabinol content was 40 °C for 30 min. The prediction was accurate due to low percent error. This optimal condition could be used as a guide for maceration of cannabis to obtain the extract containing a high content of cannabidiol and Δ9- tetrahydrocannabinol.

Validated high performance liquid chromatography for simultaneous determination of stability of madecassoside and asiaticoside in film forming polymeric dispersions

ABSTRACT The objective of the work was to validate the high performance liquid chromatography for simultaneous determination of stability of madecassoside and asiaticoside in Centella asiatica (L.) Urb., Apiaceae, extract-loaded film forming polymeric dispersions. High performance liquid chromatography method was validated in five topics: linearity and range, limit of detection and limit of quantitation, specificity, precision, and accuracy. Results showed the method had a good linearity (R2 > 0.9990) in the range of 5-150 µg/ml and specific. The limit of detection and limit of quantitation of madecassoside were 81 and 245 ng/ml and asiaticoside were 21 and 64 ng/ml, respectively. The percent relative standard deviation of intraday and interday precision were less than 1 and 3%, respectively. The accuracy presented as percent recovery was 101.54-103.29% for madecassoside and 100.39-102.58% for asiaticoside. This validated high performance liquid chromatography method was used to determine the stability of the formulation containing Centella asiatica extract. Centella asiatica extract-loaded film forming polymeric dispersions used Eudragit® RS 30D and Eudragit® RL 30D as film former, glycerin as plasticizer, and absolute ethanol as solvent and penetration enhancer. Three formulations with different ratio of Eudragit® RS 30D and Eudragit® RL 30D were prepared and stored for 90 days at 4 ºC, 25 ºC, and 40 ºC. Stability results showed that almost all of the formulations were unstable at 25 ºC and 40 ºC. Except, two of three formulations were stable at 4 ºC. However, the formulation was further developed to improve the stability of madecassoside and asiaticoside in the formulation.