Preparation of curcuminoid niosomes for enhancement of skin permeation.

Curcuminoids (curcumin, desmethoxycurcumin, and bisdesmethoxycurcumin) are major bioactive substances found in turmeric (Curcuma longa L.) extracts and possess antioxidant, anti-inflammatory, antimicrobial and anticancer properties. In this study, curcuminoid niosomes prepared with a series of Span non-ionic surfactants were developed to enhance the skin permeation of curcuminoids. Formulations were evaluated based on aggregation of niosomes, curcuminoid loading, % entrapment efficiency and in vitro permeation of curcuminoids through shed snake skin. Optimal formulations of curcuminoid niosomes including sorbitan monooleate, cholesterol, and Solulan C-24 at a mole ratio of 47.5:47.5:5 were obtained. Up to 11 micromoles of curcuminoids could be loaded in the niosome with a % entrapment efficiency of 83%. About 90% of the niosomes had a diameter of 12.25 +/- 5.00 microm. The niosomes significantly enhanced permeation of curcuminoids compared with a methanolic solution of curcuminoids: 4% of entrapped curcuminoids traversed the shed snake skin, whereas permeation from the methanolic solution was undetectable. The fluxes of curcumin, desmethoxycurcumin, and bisdesmethoxycurcumin were 1.117, 0.263, and 0.057 microg/(cm2h), respectively, consistent with the relative hydrophobicity of curcumin > desmethoxycurcumin > bisdesmethoxycurcumin. In conclusion, our data show that curcuminoids can be successfully formulated as niosomes and that such formulations have improved properties for transdermal delivery.

Development of clay liquid detergent for Islamic cleansing and the stability study.

Clay liquid detergents (CLDs) were developed for cleansing religiously-prohibited dirt ('najis') according to Islamic law. Four types of clay were selected: marl, kaolin, bentonite and veegum. After product development trials, five CLD formulations with varying combinations of clays were qualified for stability testing. Three exaggerated temperature conditions were considered: 4 degrees C for 24 h, 50 degrees C for 7 days, and 40 degrees C for 1 month. The CLDs were also evaluated at 30, 60 and 90 days after production, while being stored at room temperature (RT30, RT60 and RT90). Physical and chemical characteristics including pH, colour, viscosity, surface tension, foam tests and sensory liking scores were evaluated. Our results showed that the kaolin-based formula, F2, had an optimal pH (closest to skin pH) of 5.08. The other formulas ranged from pH 6 to 8. Colour shades of the CLDs ranged from white, to creamy white, to mildly greenish-white. The foaming properties of the CLDs, the means +/- SD of foam heights at 0 and 5 min, using the Ross-Miles test, were 19.13 +/- 0.25 to 20.88 +/- 0.45 cm at RT90 and were comparable with those of commercial detergents. Foam stability of all CLDs was high, as shown from the foam heights between 0 and 5 min being not significantly different (P > 0.05). The surface tensions, means +/- SD, of CLD solutions were between 27.94 +/- 0.08 and 28.72 +/- 0.04 mN m(-1), which were slightly better than the surface tension of 29.08 +/- 0.04 mN m(-1) for sodium lauryl sulphate. There was a weak negative relationship between surface activity and foam height, based on the pooled data of the CLDs (R(2) = 0.209, P < 0.01). The viscosity of four CLDs ranged from 16 317 to 49 036 mPa s. In conclusion, CLDs can be formulated with good stability. F2 (kaolin-based, with a white, creamy texture) was the best CLD formula. It had the highest surface activity, moderate lathering and pleasant physical appearance.

The effect of core-to-wall ratio and Span 80 concentration on the properties of ascorbic acid microcapsules.

Ethylcellulose microcapsules containing ascorbic acid were prepared by the emulsification-solvent evaporation technique. The effect of core-to-wall ratios and surfactant concentrations on the dissolution rate and size distribution of the ascorbic acid microcapsules were studied. Span 80 was used as a dispersing agent and light liquid paraffin as a continuous phase. The dissolution of ascorbic acid microcapsules was studied using the USP rotating basket method. A high core-to-wall ratio resulted in an increase of both microcapsule size and drug release rate. For a given core-to-wall ratio a high concentration of Span 80 increased the drug release rate, this was associated with the presence of drug crystals on the microcapsule surface.

Microencapsulation of drugs by the coacervation technique using ethylcellulose and acrylate-methacrylate copolymer as wall materials.

In this study, ethylcellulose and acrylate-methacrylate copolymer (Eudragit RL 100, Eudragit RS 100) membranes were prepared by using appropriate types and amounts of plasticizers. Thirty percent and 20% of triacetin based on polymer weight were found to be appropriate plasticizers for ethylcellulose membranes and acrylate-methacrylate copolymer membranes, respectively. The ratios of 3:2 and 2:3 Eudragit RL 100: Eudragit RS 100 also gave transparent and flexible membranes. Cephalexin was chosen as a model drug. The coacervation technique was investigated for the preparation of cephalexin microcapsules. Ethylcellulose and acrylate-methacrylate copolymer corresponding to the above ratios were selected as wall materials of the microcapsules. The effects of core-to-wall ratios on the surface characteristics and dissolution of the microcapsules were also studied. The coacervation technique with ethylcellulose as wall material gave the higher yield (90%) of microcapsules. The release of cephalexin from ethylcellulose walled microcapsules was slow whilst the release from those of acrylate-methacrylate copolymer was faster. The increase of deposition of wall materials due to the decrease of the core-to-wall ratio resulted in a decrease of dissolution rate.

Cellulose-walled microcapsules: 1. The effect of the solvent-non solvent proportions on the preparation of microcapsules from the system ethyl cellulose-chloroform-ethane diol.

The phase diagram of the system ethyl cellulose-chloroform-ethane diol has been studied and the differing phase regions determined. The effect of temperature of these regions is recorded. The phase diagram is used to determine the optimal conditions for the preparation of microcapsules with a phenobarbitone core and the size distribution of the microcapsules is recorded.