Process optimization of physicochemical properties of spray-dried Hydrocotyle umbellata L. extract

Abstract Hydrocotyle umbellata L., Araliaceae, is a species that is recommended in Ayurvedic medicine for its effects on the central nervous system, such as anxiolytic and memory-stimulant effects. Despite the medicinal potential of this species, its phytopharmaceutical and technological potential to produce standardized extracts has not been investigated. This study analyzes the influence of spray drying parameters on the contents of the chemical markers (total phenolic, total flavonoid, and hibalactone) and the functional properties of H. umbellata extract. The optimization of drying conditions was performed using a central composite design combined with response surface methodology and desirability function approach. The mathematical models fitted to experimental data indicated that all the evaluated drying parameters significantly influenced the chemical contents. The optimal conditions were: inlet temperature of 120 °C, feed flow rate of 4 mL min-1, and colloidal silicon dioxide:maltodextrin ratio of 16%:4%. Under these conditions, the powder samples had spherical particles and desirable physicochemical and functional properties, such as low water activity and moisture content, good product recovery, reconstitution, and flowability. Thus, spray drying might be a promising technique for processing standardized H. umbellata extracts.

Development and validation of a rapid RP-HPLC method for simultaneous quantification of paclitaxel and cetuximab in immunoliposomes.

The development of rational therapies against complex diseases, such as cancer, has increased in the past few years due to the advances of 'omics' technologies. Concomitantly, several efforts have been made to design sophisticated drug delivery systems in order to increase specificity and drug accumulation in tumor sites. The complexity of these drug delivery systems highlights the need for suitable analytical methods to determine encapsulation/conjugation efficiency of drugs and molecules responsible for the targeted delivery. Therefore, this study focuses on the development and validation of a RP-HPLC-DAD methodology for concurrent quantification of paclitaxel (PTX) and cetuximab (CTX) in immunoliposomes. Chromatographic separation was achieved using a wide pore C8 column, and a gradient mobile phase consisting of 0.1% trifluoroacetic acid (TFA) in Milli-Q water/acetonitrile/isopropanol with a flow rate of 1 mL min-1. Drug peaks were fully separated and detected at 280 nm using UV detector. The method was validated according to ICH and FDA guidelines in terms of specificity and forced degradation studies, system suitability, linearity, limit of detection, limit of quantification, repeatability, intermediate precision, accuracy, robustness, and short-term stability. The developed method was linear over the concentration range of 37.5-150 µg mL-1 of PTX and 75-300 µg mL-1 of CTX. All parameters evaluated satisfied the acceptance criteria, according to both FDA and ICH guidelines. The applicability of the analytical method was assessed following the development of PTX-loaded immunoliposomes conjugated with CTX. Thus, the present study shows a novel, simple, stability-indicating and suitable method to quantify simultaneously PTX and CTX in immunoliposomes.

A Novel Polymer-Lipid Hybrid Nanoparticle for the Improvement of Topotecan Hydrochloride Physicochemical Properties.

BACKGROUND: Topotecan (TPT) is a water-soluble derivate of camptothecin, which undergoes ring-opening hydrolysis in neutral solutions, leading to stability loss and poor cellular uptake. Lipid nanoencapsulation can improve TPT stability, and polymer-lipid hybrid nanoparticles (PLN) are interesting alternatives to improve TPT nanoencapsulation. OBJECTIVE: This study seeks to prepare complexes between the cationic TPT and the negatively charged dextran sulfate (DS) with a view of improving drug loading, chemical stability and release control. METHODS: The optimum ionic molar ratio in DS-TPT complexation was determined, and the selected complex was characterized by FTIR and solid-state 13C NMR. TPT solubility in the free and complexed forms was also assayed. TPT-PLN was then obtained via a microemulsion technique, and particle size, zeta potential, encapsulation efficiency, drug loading and drug recovery were determined. Additionally, the TPT stability and in vitro release were determined from PLN and compared with free TPT, TPT-DS complex and TPT encapsulated in nanostructured lipid carriers (NLC) of similar composition. RESULTS: TPT-DS complexation was confirmed by FTIR and NMR. TPT solubility in the complex was drastically decreased when compared to free TPT. TPT-PLN had high encapsulation efficiency (97%) and drug loading capacity (5.5%). Additionally, TPT-PLN showed a mean diameter, polidispersivity index e zeta potential of 140 nm, 0.2 and -22 mV, respectively. The TPT chemical stability and release from PLN were observed to be superior when compared to NLC. CONCLUSION: PLN has shown to be a more effective nanosystem for TPT nanoencapsulation because TPT loading, stability and release were superior when compared to TPT-NLC.

Improved tacrolimus skin permeation by co-encapsulation with clobetasol in lipid nanoparticles: Study of drug effects in lipid matrix by electron paramagnetic resonance.

Combined therapy with corticosteroids and immunosuppressant-loaded nanostructured lipid carriers (NLC) could be useful in the treatment of skin diseases. To circumvent NLC loading capacity problems, loaded drugs should have different physicochemical characteristics, such as tacrolimus (TAC) and clobetasol (CLO). Therefore, in the present study, TAC and CLO were encapsulated in NLC (TAC-NLC, CLO-NLC and TAC+CLO-NLC), coated or otherwise with chitosan. Electron paramagnetic resonance (EPR) spectroscopy of different spin labels was used to investigate the impact of drug and oil incorporation on the lipid dynamic behavior of the lipid matrices. In addition, the impact of co-encapsulation on drug release and skin permeation was evaluated. Entrapment efficiency was greater than 90% for both drugs, even when the maximum drug loading achieved for TAC-NLC and CLO-NLC was kept at TAC+CLO-NLC, because TAC is more soluble in the solid lipid and CLO in the liquid lipid. EPR data indicated that both drugs reduced the lipid fluidity near the polar surface of the lipid matrix, which suggests their presence in this region. In addition, EPR data showed that liquid lipid is also present in more superficial regions of the nanoparticle matrix. CLO was released faster than TAC from TAC+CLO-NLC, probably because it is more soluble in the liquid lipid. TAC skin penetration was affected by CLO. A 5-fold increase in TAC penetration was observed from TAC+CLO-NLC when compared to TAC-NLC formulations. Coating also increased TAC and CLO permeation to deeper skin layers (1.8-fold and 1.6-fold, respectively). TAC+CLO-NLC seems to be an effective strategy for topical delivery of TAC and CLO, and thus constitutes promising formulations for the treatment of skin diseases.

Mucoadhesive Properties of Thiolated Pectin-Based Pellets Prepared by Extrusion-Spheronization Technique.

The aim of this study was to develop mucoadhesive pellets on a thiolated pectin base using the extrusion-spheronization technique. Thiolation of pectin was performed by esterification with thioglycolic acid. The molecular weight and thiol group content of the pectins were determined. Pellets containing pectin, microcrystalline cellulose, and ketoprofen were prepared and their mucoadhesive properties were evaluated through a wash-off test using porcine intestinal mucosa. The in vitro ketoprofen release was also evaluated. Thiolated pectin presented a thiol group content of 0.69 mmol/g. Thiolation caused a 13% increase in polymer molecular weight. Pellets containing thiolated pectin were still adhering to the intestinal mucosa after 480 min and showed a more gradual release of ketoprofen. Conversely, pellets prepared with nonthiolated pectin showed rapid disintegration and detached after only 15 min. It can be concluded that thiolated pectin-based pellets can be considered a potential platform for the development of mucoadhesive drug delivery systems for the oral route.

Clobetasol-loaded nanostructured lipid carriers for epidermal targeting.

OBJECTIVES: The aim of this study was to investigate in vitro the epidermal targeting potential of clobetasol propionate-loaded nanostructured lipid carriers (CP-NLC) when compared to that of chitosan-coated (CP-NLC-C). METHODS: CP-NLC were prepared by microemulsion method and characterized by dynamic light scattering, transmission electron microscopy, in vitro release and permeation studies. To verify epidermal targeting, permeation studies were performed in two sets of experiments. For the first set, the skin was removed from the diffusion cell and stratum corneum (SC) was separated from the remaining skin (RS). For the second set, the whole epidermis (EP) was separated from the dermis (DER). CP quantification was performed in each skin layer. KEY FINDINGS: A novel clobetasol propionate-loaded NLC was produced with 1/5th of the drug dose used in commercial formulations and, even so, presented greater skin permeation. Both chitosan-coated and uncoated NLC enhanced the amount of CP in the epidermis more than 80-fold when compared to the commercial formulation (20.26 ± 2.77; 17.85 ± 0.49 and 0.22 ± 0.02 µg/cm(2) , respectively). Differently from chitosan-coated NLC, the uncoated NLC did not show dermal retention. CONCLUSIONS: NLC proved to be a system with potential for targeting drug delivery to the epidermal layer.

Comércio ambulante: qualidade microbiológica de carne assada e conhecimento sobre as boas práticas de manipulação / Street food vendors: microbiological quality of barbecued meat and knowledge of good food

O comércio de alimentos praticado por ambulantes tem aumentado nos últimos anos no Brasil, porém questiona-se a segurança alimentar desses produtos. Considerando-se o elevado consumo de carne assada nas ruas de várias cidades do País, objetivou-se, nesta pesquisa, analisar a qualidade microbiológica da carne assada (bovina) e das mãos dos manipuladores deste produto no comércio ambulante na cidade de Anápolis-GO. Pretendeu-se, também, verificar o conhecimento sobre Boas Práticas pelos comerciantes. Foram avaliados 11 pontos de venda ambulante, coletando-se uma amostra de carne bovina crua e outra de carne assada. Em cada ponto, coletou-se também uma amostra das mãos do manipulador da carne assada por meio do enxague das mãos em solução salina contida em saco plástico esterilizado. Além disso, foram aplicados questionários para verificar o conhecimento desses comerciantes sobre as normas de manipulação de alimentos. Nas amostras de carne crua, realizou-se a contagem de Escherichia coli e a pesquisa de Salmonella sp.; nas amostras de carne assada, a contagem de Staphylococcus aureus, E. coli e clostrídios sulfito-redutores e a pesquisa de Salmonella sp. Nas amostras das mãos, realizou-se a contagem de Staphylococcus aureus e Escherichia coli. A qualidade microbiológica mostrou-se satisfatória em 90,9 por cento (10/11) das amostras de carne assada. Nenhum dos manipuladores apresentou S. aureus ou E. coli nas mãos. Em relação ao conhecimento das normas de manipulação, as principais falhas identificadas referiam-se ao preparo e transporte de alimentos.

The food trade by street vendors in Brazil has increased in recent years, but there are questionsabout the food safety of these products. In view of the high consumption at street barbecues incities across the country, this study aimed to analyze the microbiological quality of barbecuedmeat sold by street vendors, while testing the adoption of good food preparation practices by thefood handlers in the city of Anápolis, Goiás. Eleven points of sale were evaluated and at each pointsamples of raw and cooked meat were collected. The cleanliness of sellers’ hands was also evaluatedthrough the collection of samples by the rinsing of their hands in saline contained in a sterile plasticbag. Questionnaires were applied to check the knowledge of vendors about food safety practices.Samples of raw meat were checked for Escherichia coli and Salmonella spp., while the samples ofcooked beef were checked for Staphylococcus aureus, E. coli, sulphite reducing Clostridium andSalmonella spp., as required by the legislation. The microbiological analysis revealed that one stallhad cooked meat of an unsatisfactory quality. None of the handlers had S. aureus or E. coli on theirhands. Regarding the knowledge of good practices, failures were noted, mainly in the preparationand transport of food.

In vitro skin penetration of clobetasol from lipid nanoparticles: drug extraction and quantitation in different skin layers

Clobetasol propionate (CP) is a potent topical corticosteroid that causes several cutaneous and systemic side effects. In the present work, CP was encapsulated in nanostructured lipid carriers (NLCs) to increase drug retention in the outer skin layers and improve the safety of topical therapy. NLCs were prepared using a microemulsion technique with a mixture of lecithin, taurodeoxycholate, stearic acid, and oleic acid. In vitro penetration studies were performed in a modified Franz-type diffusion cell, and porcine ears were used as a model of human skin. A simple and sensitive liquid chromatographic method was developed and validated for clobetasol determination in different skin layers. NLCs presented uniform size distribution, high zeta potentialand entrapment efficiency values (> 98%). The analytical procedure was validated according to FDA guidelines. Clobetasol recoveries from skin samples were higher than 85%, with no interference of skin components and NLC ingredients. In experiments, after 6 h, a higher drug accumulation in the stratum corneum arising from NLCs compared to aqueous CP solution was observed. Thus, the NLCs demonstrated high potential for targeting CP to the skin and ensuring drug accumulation in the stratum corneum.

Proprionato de clobetasol (CP) é um potente corticóide tópico, que apresenta vários efeitos adversos cutâneos e sistêmicos. No presente trabalho, CP foi encapsulado em carreadores lipídicos nanoestruturados (NLCs) visando aumentar a retenção do fármaco nas camadas superficiais da pele e a segurança da terapia tópica. NLCs foram preparados usando a técnica de diluição de microemulsão com mistura de lecitina, taurodesoxicolato, ácido esteárico e ácido oléico. Estudos de penetração in vitro foram realizados em células de difusão de Franz modificadas usando pele de orelha de porco como modelo de pele humana. Um método simples e sensível de cromatografia líquida foi desenvolvido e validado para a determinação de clobetasol nas diferentes camadas da pele. NLCs apresentaram distribuição de tamanho uniforme e valores elevados de potencial zeta e eficiência de encapsulação (>98%). O procedimento analítico foi validado de acordo com as diretrizes do FDA. A recuperação de clobetasol a partir das amostras de pele foi maior que 85%, sem interferência dos componentes da pele e dos excipientes das NLCs. Após 6 horas de experimento observou-se maior acúmulo do fármaco a partir das NLCs comparado à solução aquosa de CP. Dessa forma, as NLCs mostraram elevado potencial para direcionar o CP para a pele, pois elas possibilitaram o acúmulo do fármaco no estrato córneo.