RiceSorb® as Talcum Substitute for Loose Face Powders: Formulation and Characterization

Excessive and daily inhalation of talcum, a main ingredient of face powders, causes pulmonary talcosis, which has led to the replacement of talcum with safer natural ingredients. RiceSorb^®, or Oryza sativa starch from Japanese rice, was used as an alternative owing to its nontoxic and excellent oil absorption capacity. The objectives of the present work were to formulate loose face powders from RiceSorb^® and to investigate the physicochemical properties of the prepared formulations. Five formulations of loose face powders were prepared by varying the ratios between talcum and RiceSorb^®: 4:0 (FT0), 3:1 (FT1), 1:1 (FT2), 1:3 (FT3), and 0:4 (FT4). The physicochemical properties were evaluated mainly based on USP 41 and NF 36 such as morphology by using a scanning electron microscope, bulk density, flow property (angle of repose), moisture content (MC), and pH. The stability of the formulations were also performed at ambient temperature and 45°C for 2 months. The formulations had pH 6.90-8.62, bulk density 0.33-0.49 g/ml, and an angle of repose 30°-41°. Overall, the formulations which contained only RiceSorb^® (FT4) or higher proportion of RiceSorb^® (FT3) had finer particles, lower bulk density, pH, and angle of repose than those of the formulations containing high proportion of talcum: FT0 and FT1. Under storage conditions for 2 months, the formulations containing high proportion of RiceSorb^® exhibited noticeably increased MC and angle of repose. However, the other physicochemical properties were somewhat the same. The present results suggest the applicability of RiceSorb^® for loose face powders.

A Cold Process Preparation of Vetiveria zizanioides (L.) Nash Oil Lotions using Simulgel FL as an Emulsifier

Vetiveria zizanioides (vetiver) contains viscous volatile oil, which has the ability to repel mosquitoes similar to citronella oil, a well-known mosquito repellent in tropical countries, like Thailand. The objectives of the current study were to formulate the stable oil-in-water vetiver oil lotions using Simulgel FL as a liquid emulsifier, to investigate the physicochemical properties of the prepared lotions and to evaluate the in vitro release characteristics of the stable vetiver oil lotions. In this work, the concentrations of Simulgel FL ranged from 1% to 3% weight in weight, whereas the concentrations of vetiver oil were varied: 2.5%, 5%, and 10% weight in weight. The suitable concentration of Simulgel FL was found to be 3% weight in weight. For comparison purposes, oil-in-water citronella oil lotions (10% weightin- weight citronella oil) were also prepared with similar ingredients. A mixture of vetiver oil and citronella oil (1:1 by weight) was also used as an active ingredient. By using Simulgel FL, the lotions could be prepared using a cold process (without heat). The physicochemical properties (appearance, pH, viscosity) of the stable lotions were satisfactory. All prepared lotions possessed weak acidic pH values with pseudoplastic flows. Using modified Franz diffusion cell and synthetic membrane, the release rates of vetiver oil were relatively lower than those of citronella oil.

Effect of emulsifier pairs on physical stability of emulsions containing three different natural oils

The purpose of this study was to formulate oil-in-water (o/w) emulsions containing 40% w/w natural oil (i.e., olive oil, rice bran oil, or sesame oil), 10% w/w emulsifier blend, and 50% w/w water. The hydrophile-lipophile balance system was used to calculate the amount of each non-ionic emulsifier in the formulations. All studied oils have an identical required hydrophile-lipophile balance of 7. In emulsifier blend, polyoxyethylene (20) sorbitan monooleate (hydrophile-lipophile balance = 15.0) was fixed as a high hydrophile-lipophile balance emulsifier, while sorbitan monostearate (hydrophile-lipophile balance = 4.7) or sorbitan monooleate (hydrophile-lipophile balance = 4.3) was used as a low hydrophile-lipophile balance emulsifier. The effect of emulsifier pairs on physical properties of the prepared samples was investigated. The physical stability of the emulsions was evaluated at ambient temperature (≈ 30°C) after storage for 30 and 60 days. It was found that emulsifier pairs influenced both characteristics and stability of the samples. Sorbitan monostearate could provide stable emulsions of all studied natural oils when blended with polyoxyethylene (20) sorbitan monooleate while sorbitan monooleate could not. From the obtained results, it could be concluded that not only suitable hydrophile-lipophile balance but also suitable emulsifier pair were important parameters in emulsion formulations.

Physical stability of coconut oil lotions formulated using hydrophile-lipophile balance system of various emulsifier pairs

The aim of this study was to prepare coconut oil lotions using a hydrophile-lipophile balance system to calculate the proportion of each nonionic surfactant used. The effects of emulsifier pairs in the formulations on physical properties (i.e., appearance, emulsion type, pH, flow type, viscosity) were investigated. The physical stability of the lotions was determined at ambient temperature (approximatley 30 degrees C) after the lotions were kept for 30 as well as 60 days and in accelerated conditions (6 freeze-thaw cycles). It was found that the formulations most tolerant to such harsh conditions were F1 and F2, o/w lotions containing 40% w/w coconut oil, 50% w/w water and 10% w/w of the mixed emulsifier of a low hydrophile-lipophile balance surfactant (sorbitan monostearate) and a high hydrophile-lipophile balance surfactant (either polyoxyethylene [20] sorbitan monooleate or polyethylene [20] sorbitan monolaurate).

Effects of glucam P-20, vanillin, and fixolide on mosquito repellency of citronella oil lotions

The objective of this study was to investigate the effects of three fragrance fixatives, Glucam P-20, Vanillin, and Fixolide, on the mosquito repellent property of citronella oil lotions. In the current study, two formulae (A and B) of oil-in-water citronella oil lotions were formulated using different ingredients (emulsifiers [Cremophors or Emulwax], stiffening agents, and emollients). Citronella oil was used at 10% wt:wt. The weight ratios tested between citronella oil and each fixative were 1:0.25, 1:0.5, and 1:1. Overall, 20 formulations, including one with no fixatives for both A and B, were produced, A1-A10 and B1-B10. The repellent activities of these 20 lotions against Aedes aegypti (L.) were tested using a human-bait technique. The types and concentrations of fixatives as well as the compositions of the formulations did affect the protection time of the citronella oil lotions. The lotion containing Emulwax and 5% vanillin (B6) was the most effective repellent. It provided the longest protection time of 4.8 h, which exceeded the minimum requirement of 2 h set by the National Institute of Health, Thailand. The shortest protection time (1 h) was observed in the lotion containing Emulwax and 2.5% Glucam P-20 (B2). It could be concluded that the tested fixatives affected the repellent activity of the citronella oil lotions.

Controlled release of oral tetrahydrocurcumin from a novel self-emulsifying floating drug delivery system (SEFDDS)

The objectives of this study were to develop and evaluate a novel self-emulsifying floating drug delivery system (SEFDDS) that resulted in improved solubility, dissolution, and controlled release of the poorly water-soluble tetrahydrocurcumin (THC). The formulations of liquid self-emulsifying drug delivery system (SEDDS; mixtures of Labrasol, Cremophor EL, Capryol 90, Labrafac PG) were optimized by solubility assay and pseudo-ternary phase diagram analysis. The liquid SEDDS was mixed with adsorbent (silicon dioxide), glyceryl behenate, pregelatinized starch, sodium starch glycolate, and microcrystalline cellulose and transformed into pellets by the extrusion/spheronization technique. The resulting pellets with 22% liquid SEDDS had a uniform size and good self-emulsification property. The microemulsions in aqueous media of different self-emulsifying floating pellet formulations were in a particle size range of 25.9-32.5 nm. Use of different weight proportions of glyceryl behenate and sodium starch glycolate in pellet formulations had different effects on the floating abilities and in vitro drug release. The optimum formulation (F2) had a floating efficiency of 93% at 6 h and provided a controlled release of THC over an 8-h period. The release rate and extent of release of THC liquid SEDDS (80% within 2 h) and self-emulsifying floating pellet formulation (80% within 8 h) were significantly higher than that of unformulated THC (only 30% within 8 h). The pellet formulation was stable under intermediate and accelerated storage conditions for up to 6 months. Controlled release from this novel SEFDDS can be a useful alternative for the strategic development of oral solid lipid-based formulations.

Formulation and efficacy of triamcinolone acetonide mouthwash for treating oral lichen planus

PURPOSE

The stability of a triamcinolone acetonide mouthwash and its efficacy in treating oral lichen planus are described.

METHODS

The solubility of triamcinolone acetonide in ethanol, propylene glycol, and glycerin was determined by shaking and equilibrating an excess of triamcinolone acetonide with the solvents for 72 hours. All three solvents were used in formulating a mouthwash. A stock solution of triamcinolone acetonide standard was prepared in ethanol and diluted to yield concentrations of 2, 4, 8, 12, and 16 microg/mL. Analytical sample solutions were prepared by pipetting 0.1 mL of triamcinolone acetonide mouthwash into 10-mL volumetric flasks and diluting to volume with the mobile phase. Accelerated stability studies were conducted by storing the samples in 60-mL amber glass bottles at 45, 60, 70, and 80 degrees C and 75% relative humidity until the triamcinolone concentration decreased markedly. Efficacy was tested by 20 subjects with a clinical diagnosis of and histologically confirmed symptomatic oral lichen planus who were randomized to use the mouthwash (n = 11) or the commercially available triamcinolone acetonide paste (n = 9).

RESULTS

The mouthwash had a satisfactory shelf life and was well accepted by patients. Ten of 11 patients treated with the mouthwash for four weeks reported a positive response, and a complete response in signs and symptoms occurred in 4 and 5 of 11 patients, respectively. No significant difference in clinical improvement was observed between groups.

CONCLUSION

A triamcinolone acetonide mouthwash had a satisfactory shelf life and was well accepted by patients. It did not have a significantly different therapeutic efficacy from the commercial paste dosage form in the treatment of oral lichen planus.