Impact of concerning excipients on animal safety: insights for veterinary pharmacotherapy and regulatory considerations

OBJECTIVES

Veterinarians and pharmacists are familiar with the efficacy and safety aspects attributed to active pharmaceutical ingredients included in medicines, but they are rarely concerned with the safety of excipients present in medicines. Although generally recognized as safe, excipients are not chemically inert and may produce adverse events in certain animal populations. This review aims to present excipients of concern to these populations and highlight their relevance for rational veterinary pharmacotherapy.

EVIDENCE ACQUISITION

A comprehensive review of the literature about the existence of adverse reactions in animals caused by pharmaceutical excipients was carried out based on an exploratory study. An overview of the correct conditions of use and safety of these excipients has also been provided, with information about their function, the proportion in which they are included in the different pharmaceutical dosage forms and the usual routes of administration.

RESULTS

We identified 18 excipients considered of concern due to their potential to cause harm to the health of specific animal populations: bentonite, benzalkonium chloride, benzoic acid, benzyl alcohol, ethanol, lactose, mannitol, mineral oil, monosodium glutamate, polyethylene glycol, polysorbate, propylene glycol, sodium benzoate, sodium carboxymethylcellulose, sodium lauryl sulfate, sulfites, polyoxyethylene castor oil derivatives, and xylitol. Among the 135 manuscripts listed, only 24 referred to studies in which the substances were correctly evaluated as excipients.

CONCLUSIONS

Based on the information presented in this review, the authors hope to draw the attention of professionals involved in veterinary pharmacotherapy to the existence of excipients of concern in medicines. This information contributes to rational veterinary pharmacotherapy and supports veterinary pharmacovigilance actions. We hope to shed light on the subject and encourage studies and new manuscripts that address the safety of pharmaceutical excipients to the animal population.

Polymeric film containing pomegranate peel extract as a promising tool for the treatment of candidiasis

Polymeric films containing pomegranate peel extract (PPE) can act as a drug-delivery platform for topical treatment of candidiasis. The composition, mechanical resistance, and in vitro antifungal activity of a polymeric film containing PPE at 1.25 mg.mL^-1 were investigated. Films were prepared using a solvent casting technique. The incorporation of PPE in the polymeric matrix gave rise to homogeneous, smooth, shiny, and yellowish-brown films. FTIR spectra of the film containing PPE showed differences without compromising the stability of the extract and the matrix. SEM analysis showed the existence of interruptions in the continuity of the films with extract, which promoted a reduction in the mechanical parameters without significantly changing the tensile strength and elongation at break. Films showed adequate mechanical properties and antifungal activity against Candida albicans, C. glabrata, C. krusei and C. tropicalis.

Prospecção de extratos vegetais como coadjuvantes de higiene bucal em cães raça Labrador Retriever

O objetivo do presente estudo foi prospectar extratos vegetais como recurso terapêutico, frente à microbiota oral de cães. Para tal, foram obtidos extratos etanólicos de diferentes partes do Anacardium ocidentalis (cajueiro), Stryphnodendron adstringens (barbatimão), Punica granatum (romã), Uncaria tomentosa (unha de gato), Psidium guajava L.(goiaba), Momordica charantia L. (melão de São Caetano) e Harpagophytum procumbens (garra do diabo), preparados em diferentes concentrações. Microrganismos coletados da mucosa oral de 12 cães da raça Labrador, mantidos sob o mesmo manejo e alimentação, foram semeados em placas de petri com Agar BHI nas quais foram distribuídos circularmente discos de papel impregnados com 20µL de cada extrato em diferentes concentrações. Solução de digluconato de clorexidina a 0,12% em discos foi utilizada como controle positivo. Foram coletados três swabs de cada animal sendo então o experimento realizado em triplicata. As placas foram incubadas por 12 horas, a 36º C. Os resultados das medidas dos halos de inibição foram submetidos à análise de variância de Kruskall-Wallis, seguida do teste de Dunn, com nível de significância de 5%. Com base nos resultados os extratos de romã, goiaba e barbatimão foram selecionados, pois mostraram-se estatisticamente significativos nas concentrações 250; 125; 62,6mg/mL o que sugere que os três extratos são candidatos potenciais para uso no desenvolvimento de produtos farmacêuticos para uso na higienização bucal dos cães.

Advances and challenges in nanocarriers and nanomedicines for veterinary application

To ensure success in the development and manufacturing of nanomedicines requires forces of an interdisciplinary team that combines medicine, engineering, chemistry, biology, material and pharmaceutical areas. Numerous researches in nanotechnology applied to human health are available in the literature. Althought, the lack of nanotechnology-based pharmaceuticals products for use exclusively in veterinary pharmacotherapy creates a potential area for the development of innovative products, as these animal health studies are still scarce when compared to studies in human pharmacotherapy. Nano-dosage forms can ensure safer and more effective pharmacotherapy for animals and can more be safer for the consumers of livestock products, once they can offer higher selectivity and smaller toxicity associated with lower doses of the drugs. In addition, the development and production of nanomedicines may consolidate the presence of pharmaceutical laboratories in the global market and can generate greater profit in a competitive business environment. To contribute to this scenario, this article provides a review of the main nanocarriers used in nanomedicines for veterinary use, with emphasis on liposomes, nanoemulsions, micelles, lipid nanoparticles, polymeric nanoparticles, mesoporous silica nanoparticles, metallic nanoparticles and dendrimers, and the state of the art of application of these nanocarriers in drug delivery systems to animal use. Finnaly, the major challenges involved in research, scale-up studies, large-scale manufacture, analytical methods for quality assessment, and regulatory aspects of nanomedicines were discussed.

Polymeric films containing pomegranate peel extract based on PVA/starch/PAA blends for use as wound dressing: In vitro analysis and physicochemical evaluation

Chronic wounds constitute a serious public health problem, and developing pharmaceutical dosage forms to ensure patient comfort and safety, as well as optimizing treatment effectiveness, are of great interest in the pharmaceutical, medical and biomaterial fields. In this work, the preparation of films based on blends of poly(vinyl alcohol), starch and poly(acrylic acid), polymers widely used as pharmaceutical excipients, and pomegranate peel extract (PPE), a bioactive compound with antimicrobial and healing activities relevant to the use as a bioactive wound dressing, was proposed. Initially, the minimum inhibitory concentration (MIC) of the PPE was investigated by an in vitro method. Then, the best concentration of the PPE to be used to prepare the films was researched using an antimicrobial susceptibility test with the disc diffusion method. The microbiological assay was performed in films prepared by the solvent casting method in the presence of two concentrations of PPE: 1.25% w/v and 2.5% w/v. Films containing the lower PPE concentration showed antimicrobial activity against Staphylococcus aureus and Staphylococcus epidermidis, with a difference that was not considered statistically significant when compared to the higher concentration of the extract. Therefore, the films prepared with the lower proportion of PPE (1.25% w/v) were considered for the other studies. The miscibility and stability of the extract in the films were investigated by thermal analysis. Parameters that determine the barrier properties of the films were also investigated by complementary techniques. Finally, in vitro biological tests were performed for safety evaluation and activity research. Analysis of the results showed that the incorporation of the higher proportion of starch in the blend (15% v/v) (PVA:S:PAA:PPE4) yielded smooth, transparent, and domain-free films without phase separation. Additionally, the PVA:S:PAA:PPE4 film presented barrier properties suitable for use as a cover. These films, when subjected to the in vitro hemolytic activity assay, were nonhemolytic and biocompatible. No toxicity from the extract was observed at the concentrations studied. The results of the wound healing in vitro test showed that films containing 1.25% PPE are efficient in reducing the scratch open area, provoking almost total closure of the scratches within 48 h without cytotoxicity.

Electrospun poly(ε-caprolactone) matrices containing silver sulfadiazine complexed with β-cyclodextrin as a new pharmaceutical dosage form to wound healing: preliminary physicochemical and biological evaluation

Cooperation between researchers in the areas of medical, pharmaceutical and materials science has facilitated the development of pharmaceutical dosage forms that elicit therapeutic effects and protective action with a single product. In addition to optimizing pharmacologic action, such dosage forms provide greater patient comfort and increase success and treatment compliance. In the present work, we prepared semipermeable bioactive electrospun fibers for use as wound dressings containing silver sulfadiazine complexed with β-cyclodextrin in a poly(Ɛ-caprolactone) nanofiber matrix aiming to reduce the direct contact between silver and skin and to modulate the drug release. Wound dressings were prepared by electrospinning, and were subjected to ATR-FT-IR and TG/DTG assays to evaluate drug stability. The hydrophilicity of the fibrous nanostructure in water and PBS buffer was studied by goniometry. Electrospun fibers permeability and swelling capacity were assessed, and a dissolution test was performed. In vitro biological tests were realized to investigate the biological compatibility and antimicrobial activity. We obtained flexible matrices that were each approximately 1.0 g in weight. The electrospun fibers were shown to be semipermeable, with water vapor transmission and swelling indexes compatible with the proposed objective. The hydrophilicity was moderate. Matrices containing pure drug modulated drug release adequately during 24 h but presented a high hemolytic index. Complexation promoted a decrease in the hemolytic index and in the drug release but did not negatively impact antimicrobial activity. The drug was released predominantly by diffusion. These results indicate that electrospun PCL matrices containing β-cyclodextrin/silver sulfadiazine inclusion complexes are a promising pharmaceutical dosage form for wound healing.

OBTENÇÃO E CARACTERIZAÇÃO DO COMPLEXO DE INCLUSÃO FURAZOLIDONA:β-CICLODEXTRINA

A furazolidona é um fármaco que apresenta baixa solubilidade em água, o que prejudica sua biodisponibilidade e requer o emprego de doses elevadas, podendo causar reações adversas indesejáveis. Ainda, o fármaco é fotossensível, o que pode comprometer sua estabilidade. Uma alternativa farmacotécnica amplamente utilizada para melhorar a solubilidade e a consequente dissolução e biodisponibilidade de fármacos pouco solúveis é o uso das ciclodextrinas. A formação dos complexos de inclusão com estes excipientes pode, também, promover a estabilização do fármaco. Neste sentido, o objetivo do presente trabalho foi preparar e caracterizar    complexos de inclusão entre a furazolidona e a β-ciclodextrina. Os complexos foram obtidos em meio sólido, por malaxagem, e a caracterização foi feita pelas técnicas de microscopia eletrônica de varredura, espectrometria na região do infravermelho por transformada de Fourier e análises térmicas. Resultados preliminares sugerem o sucesso da complexação.

PREPARAÇÃO DE PÓS MEDICAMENTOSOS DIVIDIDOS CONTENDO CLORIDRATO DE PROPRANOLOL PARA USO PEDIÁTRICO

A farmacoterapia pediátrica requer o emprego de formas farmacêuticas diferenciadas, uma vez que estes pacientes apresentam capacidade de deglutição, preferência de sabor e necessidades terapêuticas também diferenciadas. Neste contexto, considerar a preparação do fármaco em outra forma farmacêutica, a qual permanecerá estável e permitirá a tomada de doses adequadas, é atribuição do profissional farmacêutico. Para auxiliar a preencher a lacuna existente no mercado, o presente trabalho foi proposto. Foram preparados pós medicamentosos divididos contendo cloridrato de propranolol, visando solubilização prévia em pequenos volumes de água. Como são idealizadas para reconstituição imediatamente antes do uso, problemas de estabilidade podem ser contornados. As soluções originadas podem ser edulcoradas e flavorizadas. De acordo com os resultados obtidos, a matéria-prima cloridrato de propranolol cumpriu com os requisitos farmacopeicos de qualidade pesquisados. As formulações mostraram ser solúveis em 3 mL e 5 mL de água. Análises quantitativas para determinação do teor de fármaco e de uniformidade de dose estão sendo realizadas. 

DESENVOLVIMENTO DE GOMA MEDICAMENTOSA DE GELATINA CONTENDO EXTRATO AQUOSO DAS CASCAS DOS FRUTOS DA JABUTICABEIRA

O uso de fitoterápicos foi incorporado ao Sistema Único de Saúde por meio do Decreto Nº 5.813, de 22 de junho de 2006 e, nas últimas décadas, o interesse da população pelo uso de produtos farmacêuticos preparados a partir de plantas medicinais tem aumentado significativamente. Inúmeros estudos relatam o sucesso do uso de extratos no preparo de medicamentos, cosméticos e produtos de higiene. Aos extratos das folhas, caules e frutos da Plinia cauliflora, conhecida como jabuticaba, são atribuídas atividades antibiótica e antifúngica. Neste contexto, o presente trabalho teve como objetivo principal a obtenção de extrato aquoso das cascas dos frutos da jabuticabeira, visando posterior incorporação em gomas medicamentosas, com o intuito de obter preparações antissépticas. Após o preparo, o extrato foi submetido à triagem fitoquímica, que confirmou a presença de taninos e flavonóides. Após obtenção da base, o extrato foi incorporado e as gomas medicamentosas foram obtidas por moldagem. Os produtos finais apresentaram textura e sabor agradável e cumpriram com as especificações para o ensaio de médio.

DESCARTE CONSCIENTE DE MEDICAMENTOS: RELATO DE EXPERIÊNCIA

O presente trabalho teve como objetivo sensibilizar um grupo de alunos do ensino médio do município de Alegre (ES) sobre a importância do descarte consciente de medicamentos, com o intuito de torná-los multiplicadores das informações adquiridas. O projeto foi desenvolvido mediante a realização de aulas ministradas por alunos de graduação do curso de Farmácia da UFES e de um tutor da escola. Os alunos mostraram-se interessados e preocupados com a situação do descarte incorreto no município de Alegre, sendo estimulados a refletirem a partir de um problema mundial e a proporem alternativas para intervirem no descarte de medicamentos no âmbito local.

Pharmaceutical acrylic beads obtained by suspension polymerization containing cellulose nanowhiskers as excipient for drug delivery

Direct compression is one of the most popular techniques to prepare tablets but only a few commercial excipients are well adapted for this process into controlled release formulations. In the last years, the introduction of new materials for drug delivery matrix tablets has become more important. This paper evaluated the physicochemical and flow properties of new polymeric excipient of ethyl acrylate, methyl methacrylate and butyl metacrylate, synthesized by suspension polymerization using cellulose nanowhiskers as co-stabilizer, to be used as direct compression for modified release tablets. Infrared spectroscopy (FTIR) confirmed the success of the copolymerization reaction. Scanning electron microscopy (SEM) showed that excipient was obtained how spherical beads. Thermal properties of the beads were characterized by thermogravimetric (TG) analysis. Particle size analysis of the beads with cellulose nanowhiskers (CNWB) indicated that the presence of the nanowhiskers led to a reduction of particle size and to a narrower size distribution. In vitro test showed that the nanowhiskers and beads produced are nontoxic. Parameters such as Hausner ratio, Carr's index and cotangent of angle α were employed to characterize the flow properties of CNWB beads. Furthermore, the beads are used to produce tablets by direct compression contained propranolol hydrochloride as model drug. Dissolution tests performed suggested that beads could be used as excipient in matrix tablets with a potential use in drug controlled release.