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Previous studies have demonstrated the antiherpes activity of pentyl gallate (PG), suggesting that it could be a promising candidate for the topical treatment of human herpes labialis. PG low aqueous solubility represents a major drawback to its incorporation in topical dosage forms. Hence, the feasibility of incorporating PG into nanoemulsions, the ability to penetrate the skin, to inhibit herpes simplex virus (HSV)-1 replication, and to cause dermal sensitization or toxicity were evaluated. Oil/water nanoemulsions containing 0.5% PG were prepared by spontaneous emulsification. The in vitro PG distribution into porcine ear skin after topical application of nanoemulsions was assessed, and the in vitro antiviral activity against HSV-1 replication was evaluated. Acute dermal toxicity and risk of dermal sensitization were evaluated in rat model. Nanoemulsions presented nanometric particle size (from 124.8 to 143.7 nm), high zeta potential (from -50.1 to -66.1 mV), loading efficiency above 99%, and adequate stability during 12 months. All formulations presented anti-HSV-1 activity. PG was able to reach deeper into the dermis more efficiently from the nanoemulsion F4. This formulation as well as PG were considered safe for topical use. Nanoemulsions seem to be a safe and effective approach for topically delivering PG in the treatment of human herpes labialis infection.

Copaiba oil has been widely used in popular medicine because of its anti-inflammatory properties. The oil is extracted from trees of the genus Copaifera , found mainly in the Brazilian Amazon. A study was conducted using a 2 IV 4-1 fractional factorial design to evaluate the effects of oil core and surfactants composition on physicochemical properties of nanoemulsions produced by high-pressure homogenization and spontaneous emulsification. Also, the stability of the formulations stored at 4 °C and 25 °C was monitored for 90 days. The high-pressure homogenization method proved to be the most efficient technique to obtain stable Copaiba oil nanoemulsions with reduced loss of volatile fraction within 90 days of storage at the recommended temperature (4 °C). The most suitable nanoemulsion composition was achieved adding 20% Copaiba oil, 10% medium chain triglycerides, 3% Span 80 ® and 1% Tween 20 ® . The use of medium chain triglycerides was shown to be a good strategy to fix volatile fractions of Copaiba oil incorporated into nanoemulsions during preparation and storage.

Carbamazepine (CBZ) is available on the pharmaceutical market as tablets, capsules, and oral suspensions, but not as a parenteral formulation for clinical use. Parenteral emulsions are a good alternative to poorly water-soluble drugs such as CBZ. In this way, four different emulsions containing 3 mg/mL of CBZ were developed, but during a period of storage, drug crystal precipitates appeared. To investigate this phenomenon, differential scanning calorimetry, infrared spectroscopy, and light microscopy were employed. The results suggested a polymorphic transition from beta form to dehydrate form, resulting in drug precipitation, although the emulsions themselves remained stable for at least three months.

Carbamazepine (CBZ), a widely used anticonvulsant drug, is a poorly soluble drug with no parenteral treatment available for patients. This study was aimed at developing a nanoemulsion for CBZ intravenous delivery. The spontaneous emulsification method was used to prepare different formulations containing 2 mg/mL CBZ. Likewise, a 2 2 full factorial experimental design was applied to study the influence of two independent variables (type of oil and type of lipophilic emulsifier) on emulsion physicochemical characteristics. The nanoemulsions were evaluated concerning droplet size, zeta potential, viscosity, drug content and association to oily phase. The formulation, which presented the best characteristics required for intravenous administration was selected and refined with respect to the lipophilic emulsifier content (increase from 5% to 6% of soy lecithin). This formulation was characterized and kept its properties in a satisfactory range over the evaluated period (3 months), i.e. droplet size around 150 nm, drug content around 95% and zeta potential around −40 mV. The transmission electron microscopy revealed emulsion droplets almost spherical in shape with an amorphous core, whereas the in vitro release profile assessed by dialysis bags demonstrated a release kinetics square root time dependent, with 95% of ca. having been released within 11 h.

A high performance liquid chromatographic method was developed and validated for the quantitative determination of carbamazepine in intravenous nanoemulsions. The method validation yielded good results with respect to linearity, specificity, precision and accuracy. The method was carried out on a RP-18 column with a mobile phase composed of methanol–water (70:30 v/v) subjected to a gradient of acetonitrile after drug elution, and detection at 286 nm. The linearity in the range of 10.0–50.0 μg mL−1 presented a determination coefficient (r 2) of 0.9996, calculated by least-squares regression; the RSD values for intra-day and inter-day precision for % recovered were

The thermal behaviour of fluoxetine hydrochloride and five capsules available in Florianopolis, Brazil was investigated. The raw material’s purity, kinetic parameters, thermal behaviour and melting characteristics were determined by differential scanning calorimetry and thermogravimetric analysis, as well as the thermal study of the capsules. The purity was 99.12±0.15%. The thermal decomposition followed a zero order kinetic, activation energy of 88.67 kJ mol–1 and frequency factor of 3.539·107 min–1. DSC curves obtained from the capsules suggest compatibility between the drug and excipient.

Recent studies have shown the anti-inflammatory activity of Copaiba oils may be addressed to the high content of β-caryophyllene, the most common sesquiterpene detected, especially in the Copaifera multijuga Hayne species. In the present study, nanoemulsions were proposed as a delivery system for copaiba oil in view to treat locally inflamed skin. This article describes the optimization and validation of a stability-indicating SPME-GC method, for β-caryophyllene analysis in the nanoemulsions produced by high pressure homogenization. SPME methods are performed with PDMS (polydimethylsiloxane) fiber (100 μm). Three SPME parameters were evaluated by a three-level-three-factor Box-Behnken factorial design as potentially affecting the technique efficiency. According to the results obtained, the best conditions to extract β-caryophyllene were: (i) sampling temperature of 45°C, (ii) sampling time of 20 min and (iii) no NaCl addition. Results coming from the forced degradation tests showed a reduction of β-caryophyllene peak area when both caryophyllene methanolic solution and nanoemulsions were exposed to acid hydrolysis, UV-A irradiation, oxidative (H(2)O(2)) and thermolitic (60°C) conditions. Such reduction occurred in lower extent in the nanoemulsions, suggesting a protective effect of the formulation to β-caryophyllene content. Since no degradation products were detected in the same retention time of β-caryophyllene, the specificity of the method was demonstrated. The method was linear in the range of 0.14-0.68 μg mL(-1) of β-caryophyllene (r(2)>0.999), and was also validated for precision (R.S.D.≤5.0%), accuracy (97.85-101.87%) and robustness. Finally, the method was applied to quantification of β-caryophyllene content in the developed formulations.

This work describes the pharmacokinetics of a novel carbamazepine nanoemulsion. The plasma concentration profiles were determined in beagle dogs after i.v. bolus administration of a 5 mg/kg carbamazepine nanoemulsion and compared to the corresponding carbamazepine/hydroxypropyl-beta-cyclodextrin complex solution. Both formulations showed similar pharmacokinetic profiles and could represent valuable formulations in case of emergencies, when a rapid action in the central nervous system is desirable.