Evaluation of the antibacterial synergism of two plant extracts belonging to Bignoniaceae family and development of a topical formulation

Abstract Fridericia caudigera and Cuspidaria convoluta (Bignoniaceae) species, which grow in the northwest of Argentina, have shown antibacterial effect against strains isolated from skin infections, and each one displayed synergism with commercial antibiotics. The aims of this work were to evaluate the antibacterial activity and toxicity of the combination of these two plant species, and to design a stable gel for topical use including the blend of extracts. The combination of extracts was evaluated for synergistic effects (chequerboard assay), genotoxicity (Ames test) and cytotoxicity (Artemia salina test). A gel was subsequently formulated with the combination of extracts using carboxymethylcellulose as a polymer. The following physico- chemical characteristics of the gel formulation: pH, viscosity, spreadability and total phenol content, as well as resistance to severe temperature changes, biological activity (diffusion in agar), in vitro permeation (Franz cells) and primary dermal irritation (Draize test) were analyzed. The combination of extracts showed a synergistic effect on pathogenic bacteria and was not toxic in the in vitro tests. The gel was stable and retained the antimicrobial activity of the original extracts. The formulation proposed in this work could constitute an alternative for primary skin infections since it proved to be safe for topical administration.

In Vivo Evaluation Of Tazarotene Solid Lipid Nanoparticles Gel For Topical Delivery

The purpose of this research work was to develop and optimize the Solid Lipid Nanoparticles (SLNs) of Tazarotene for the effective topical delivery in the treatment of psoriasis. Tazarotene loaded SLNs were prepared by hot homogenization followed by the ultrasonication using Taguchi’s design and based on the results further investigation was made using central composite design. The lipid Dynasan-116, surfactant poloxomer-188 and co surfactant egg lecithin resulted in better percent drug loading and evaluated for particle size, zeta potential, TEM, drug entrapment efficiency, in vitro drug release and stability. All parameters were found to be in an acceptable range. In vitro drug release of optimized SLN formulation (F1) was found to be 98.12 ± 1.52%, whereas pure drug release was 42.12 after 60 min. The optimized formulation was incorporated into the gel. The release rate (flux) of tazarotene across the membrane and excised skin differs significantly. The accumulative amount of Tazarotene in skin from SLN based gel formulation and marketed gel were 41.12 ± 0.12 mg and 30.02 ± 0.04 mg respectively. This result supported our hypothesis made in skin permeation studies on rat skin. From histopathological studies the microscopic observations indicate that the optimized SLN formulation, SLN based gel formulation and marketed gel has no significant effect on the microscopic structure of the skin. The skin-irritation studies indicated that SLN based gel containing Tazarotene did not show any sign of skin irritation as compared to moderate erythema shown by marketed gel formulation (Tazret® gel) after 72 h of application. Thus, SLN based gel formulation demonstrated advantage over marketed formulation in improving the skin tolerability of Tazarotene indicating their potential in improving patient acceptance and topical delivery of Tazarotene.

Formulation and Evaluation of Solid Lipid Nanoparticle (SLN) Based Topical Gel of Etoricoxib.

The objective of present investigation was to prepare & evaluate solid lipid nanoparticle (SLN) based topical gel of non- steroidal anti-inflammatory drug (NSAID) etoricoxib for the treatment of arthritis which would attenuate the gastrointestinal related toxicities associated with oral administration. SLN were formulated by melt emulsification and solidification at low temperature method using stearic acid & tween 80. All the formulation were subjected to particle size, particle size distribution, zeta potential, scanning electron microscopy, crystallinity study by DSC and in-vitro release studies. It has been observed that, the high lipid concentration containing formulation have higher entrapment as compare to other two formulation. The SLN- dispersion shows 70.766% entrapment & zeta potential of the formulation were -25.6 which indicates the stability of formulation. The In Vitro drug release rate of gel was evaluated using Modified franz diffusion cell containing dialysis membrane with phosphate buffer pH 7.4 as the receptor medium. The in-vitro release was carried out in comparison with a carbopol gel & hydroxypropylmethylcellulose (HPMC) gel. The permeability parameters steady-state flux (Jss) was significantly increased in SLN-F3C (carbopol) formulation as compared with SLN-F3HPMC (hydroxypropyl methylcellulose) formulation. It was concluded that the Etoricoxib loaded SLN based gel formulation containing carbopol was suitable for topical application and shows much better result of anti-inflammatory activity.

Recent Advances in Topical Gel Formulation.

Transdermal drug delivery systems are a constant source of interest because of the benefits that they afford in overcoming many drawbacks associated with other modes of drug delivery (i.e. oral, intravenous). Topical gels are becoming more popular due to ease of application and better precutaneous absorption. Gels are semisolid formulations, which have an external solvent phase, may be hydrophobic or hydrophilic in nature, and are immobilized within the spaces of a three-dimensional network structure. Gel formulations provide better application property and stability in comparison to cream and ointments. Skin is one of the most extensive and readily accessible organs on human body for topical administration and is main route of topical drug delivery system. Topical gels are intended for skin application or to certain mucosal surfaces for local action or percutaneous penetration of medicament or for their emollient or protective action. Recent studies have reported other types of gels for dermal drug application, such as proniosomal gels, emulgels, bigels and aerogels. This review is concern with all detail information regarding novel approaches to topical gel formulation, advantages and classification of gel.

Nanostructured lipid carrier based topical gel of Ganoderma Triterpenoids for frostbite treatment / 中国天然药物

The objective of this study was to prepare nanostructured lipid carrier (NLC)-based topical gel of Ganoderma Triterpenoids (GTs) and evaluate their effects on frostbite treatment. GT-NLCs was prepared by the high pressure homogenization method and then characterized by morphology and analyses of particle size, zeta potential, entrapment efficiency (EE), and drug loading (DL). The NLCs was suitably gelled for skin permeation studies in vitro and pharmacodynamic evaluation in vivo, compared with the GT emulgel. The GT-NLC remained within the colloidal range and was uniformly dispersed after suitably gelled by carbopol preparation. Transmission electron microscopy (TEM) study showed GT-NLCs was spherical in shape. The EE (%) and DL (%) could reach up to (81.84 ± 0.60)% and (2.13 ± 0.12)%, respectively. The result of X-ray diffractograms (XRD) showed that GTs were in an amorphous state in the NLC-gel. In vitro permeation studies through rat skin indicated that the amount of GTs permeated through skin of GT-NLCs after 24 h was higher than that of GT emulsion, and GT-NLCs increased the accumulative amounts of GTs in epidermis 7.76 times greater than GT emulsion. GT-NLC-gel was found to possess superior therapeutic effect for frostbite, compared with the GT emulgel. The NLC based topical gel of GTs could improve -their therapeutic effect for frostbite.