Copaiba Oil: Chemical Composition and Influence on In-vitro Cutaneous Permeability of Celecoxib.

BACKGROUND: Use of topical or transdermal administration of Celecoxib (Cxb) is an interesting strategy in cutaneous treatments since it reduces or avoids side effects of the oral route. However, Cxb´s high lipophilicity and the stratum corneum (SC) barrier impair cutaneous penetration. OBJECTIVE: Evaluation of copaiba oil (C.O) as a potential skin penetration enhancer (P.E) for Cxb. METHODS: The chemical composition of C.O was evaluated by GC-MS. Both in-vitro release and permeability assay of Cxb in Polyethylene glycol 400/ propylene glycol (PEG 400/PG) vehicle associated to C.O (1-50% w/w) were determined in a modified diffusion cell fitted with a synthetic hydrophobic membrane and pig ear skin as model, respectively. RESULTS: GC-MS analysis of C.O showed that it is composed of sesquiterpenes (68.65%) and diterpenes (22.26%). Formulations containing 25% C.O (F4) and 50% C.O (F5) have shown in-vitro burst release in the first 2 h, but only F4 released 100% of drug after 24 h. The highest Cxb permeation across skin was obtained from F4 and the highest skin retentions for F4 and F5 in the stratum corneum and epidermis plus dermis. CONCLUSION: The increased Cxb permeability through skin and its retention for an extended time (24h) at 25% C.O suggest that it could be a promising adjuvant for the development of transdermal formulations of Cxb.

Selective and cost-effective protocol to separate bioactive triterpene acids from plant matrices using alkalinized ethanol: Application to leaves of Myrtaceae species.

BACKGROUND: Triterpenes as betulinic (BA), oleanolic (OA) and ursolic acids (UA) have increasingly gained therapeutic relevance due to their wide scope of pharmacological activities. To fit large-scale demands, exploitable sources of these compounds have to be found and simple, cost-effective methods to extract them developed. Leaf material represents the best plant sustainable raw material. To obtain triterpene acid-rich extracts from leaves of Eugenia, Psidium and Syzygium species (Myrtaceae) by directly treating the dry plant material with alkalinized hydrated ethanol. This procedure was adapted from earlier methods to effect depolymerization of the leaf cutin. MATERIALS AND METHODS: Extracts were prepared by shaking the milled dry leaves in freshly prepared 2% NaOH in 95% EtOH solution (1:4 w/v) at room temperature for 6 h. Working up the product in acidic aqueous medium led to clear precipitates in which BA, OA and UA were quantified by gas chromatography. RESULTS: Pigment-free and low-polyphenol content extracts (1.2-2.8%) containing 6-50% of total triterpene acids were obtained for the six species assayed. UA (7-20%) predominated in most extracts, but BA preponderated in Eugenia florida (39%). Carried out in parallel, n-hexane defatted leaves led to up to 9% enhancement of total acids in the extracts. The hydroalcoholate treatment of Myrtaceae species dry leaves proved to be a cost-effective and environmentally friendly method to obtain triterpene acids, providing them be resistant to alkaline medium. These combined techniques might be applicable to other plant species and tissues.

Development of an HPLC method for the determination of tetranortriterpenoids in Carapa guianensis seed oil by experimental design.

Carapa guianensis crabwood, popularly known in Brazil as "andiroba", is a tree that grows in South and Central America and is used by the local population mainly for its anti-inflammatory and insect anti-feeding activities. Scientific studies on this plant have led to the development of an insect-repellent candle and the investigations of the anti-inflammatory properties of its more important biomarkers-tetranortriterpenoids. These compounds, together with glycerides and fatty acids, are present in the seed oil, the most important commercial product from this plant. The growing scientific and commercial interest in "andiroba oil" has urged the development of adequate analytical methods for assessing its quality. Central composite experimental design is a useful statistical method for the development and optimization of HPLC methods, and has been used for a variety of samples. The aim of this work is to develop a HPLC method for the determination of tetranortriterpenoids in "andiroba" oil, by means of central composite experimental design, as well as to prevalidate this method.

Purification of betulinic acid from Eugenia florida (Myrtaceae) by high-speed counter-current chromatography.

A high yield of betulinic acid (up to 17% from the ethanolic extract) was found in the leaves of Eugenia florida collected in south-eastern Brazil, making this species a potential commercial source of the title compound. Extracts of E. florida were subjected to solvent partition, and rapid high-speed counter-current chromatography (HSCCC) was applied to the semi-crude extracts to afford betulinic acid in high purity. The mobile and stationary phases were derived from the two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (10:5:2.5:1). The developing solvent system (stationary and mobile phases) for optimum HSCCC separation was chosen by dissolving the fraction to be chromatographed in the proposed solvent mixture and determining the amount of betulinic acid in each phase by densitometric TLC. Purified betulinic acid was characterized by 13C-NMR, GC-MS and co-injection of its methyl ester with standards in GC-FID. The HSCCC technique is commonly employed to isolate triterpene glycosides, but is applied in this study to an aglycone.