Cutaneous Crospovidone: A Newly Described Foreign Body Due to Illicit Drug Abuse.

Crospovidone, a polymer of poly N-vinyl-2-pyrrolidone, is an inert insoluble disintegrant found in pharmaceutical tablets. This material has been encountered in the lungs of intravenous drug users and embolized with other components such as talc and microcrystalline cellulose. More recently, crospovidone has also been described in the gastrointestinal tract. We present 2 cases of cutaneous crospovidone deposition resulting from subcutaneous injection of crushed tablets, commonly known as "skin popping." Clinical presentation includes painful, inflamed papules, nodules, or ulcers with overlying eschar. Crospovidone has a distinct and reproducible histochemical staining profile. Histologic recognition of this material is important because it can guide clinicians in their diagnosis and management decisions.

Poly(2-Ethyl-2-Oxazoline) as an Alternative to Poly(Vinylpyrrolidone) in Solid Dispersions for Solubility and Dissolution Rate Enhancement of Drugs.

Poly(2-ethyl-2-oxazoline) (PEOX), a biocompatible polymer considered as pseudopolypeptide, was introduced as a potential alternative to the commonly used polymer, poly(vinylpyrrolidone) (PVP) for the preparation of solid dispersion with a poorly soluble drug. Glipizide (GPZ), a Biopharmaceutical Classification System class II model drug, was selected for solubility and dissolution rate study. GPZ-polymer solid dispersions and physical mixtures were characterized and investigated by X-ray diffractometry, differential scanning calorimetry, scanning electron microscopy, and FTIR spectroscopy. The impact of polymers on crystal nucleation kinetics was studied, and PEOX exhibited strong inhibitory effect compared with PVP. Solubility and dissolution behavior of the prepared solid dispersions and their physical blends were in vitro examined and evaluated. A significant enhancement in GPZ solubility was obtained with PEOX compared with the pure drug and solid dispersion with PVP. A big improvement in the intrinsic dissolution rate (45 times) and dissolved amount of GPZ (58 times) was achieved with PEOX in fasted state simulated intestinal fluid, against comparable enhancement observed with PEOX and PVP in phosphate buffer at pH 6.8. Lower molecular weight of PEOX-5K (5000 g/mol) was found to be superior to higher molecular weight PEOX-50K (50,000 g/mol) in the improvement of dissolution behavior. The findings of this study with GPZ as a model drug introduce lower molecular weight PEOX as a promising polymeric carrier toward better oral bioavailability of poorly soluble drugs.

Characterization and quantitation of PVP content in a silicone hydrogel contact lens produced by dual-phase polymerization processing.

Polyvinylpyrrolidone (PVP) has been incorporated over the years into numerous hydrogel contact lenses as both a primary matrix component and an internal wetting agent to increase lens wettability. In this study, complementary analytical techniques were used to characterize the PVP wetting agent component of senofilcon A and samfilcon A contact lenses, both in terms of chemical composition and amount present. Photo-differential scanning calorimetry (photo-DSC), gas chromatography with a flame ionization detector (GC-FID), and high-resolution/accurate mass (HR/AM) liquid chromatography-mass spectrometry (LC-MS) techniques confirmed dual phase reaction and curing of the samfilcon A silicone hydrogel material. Gel permeation chromatography (GPC) demonstrated that high molecular weight (HMW) polymer was present in isopropanol (IPA) extracts of both lenses. High-performance liquid chromatography (HPLC) effectively separated hydrophilic PVP from the hydrophobic silicone polymers present in the extracts. Collectively, atmospheric solids analysis probe mass spectrometry (ASAP MS), Fourier transform infrared (FTIR) spectroscopy, 1 H nuclear magnetic resonance (NMR) spectroscopy, GC-FID, and LC-MS analyses of the lens extracts indicated that the majority of NVP is consumed during the second reaction phase of samfilcon A lens polymerization and exists as HMW PVP, similar to the PVP present in senofilcon A. GC-FID analysis of pyrolyzed samfilcon A and senofilcon A indicates fourfold greater PVP in samfilcon A compared with senofilcon A. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1064-1072, 2018.

Triagem de vários excipientes para compressão direta: uma nova perspectiva com base nas propriedades funcionais / Screening of several excipients for direct compression of tablets: a new perspective based on functional properties

Os excipientes são materiais amplamente utilizados para formular fármacos através de compressão direta. No entanto, as propriedades do pó e compressão desses materiais são afetadas pela presença de lubrificantes e ingredientes ativos. Este estudo utilizou uma metodologia para avaliar a eficácia destes materiais como agentes de compressão direta. O efeito de três lubrificantes (estearato de magnésio, ácido esteárico e talco) na compressibilidade e compactação dos materiais foi avaliado pelo índice de compressibilidade e sensibilidade do lubrificante, respectivamente. Da mesma forma, a capacidade da diluição foi avaliada com um fármaco pouco compressível como o acetaminofeno. Finalmente, a recuperação elástica dos comprimidos foi avaliada aos cinco dias após a produção. Todos os lubrificantes aumentaram a compressibilidade destes materiais e a sua fluidez. No entanto, os lubrificantes hidrofóbicos, tais como o estearato de magnésio tem um efeito negativo sobre a compactação, em especial em materiais plásticos com uma superfície lisa, como o amido 1500. O amido de arroz e de mandioca e ácido algínico apresentaram a maior recuperação elástica (> 5%), indicando uma elevada tendência para a laminação. Além disso, os materiais plásticos com alta deformação, tais como o sorbitol, e polivinilpirrolidona (PVP-K30), exibiram a melhor potencial de diluição (~10%), enquanto que o ácido algínico mostrou um valor muito elevado (~ 70%). Em termos de desempenho, o sorbitol, o PVP-K30, alginato de sódio, Avicel PH-101, e de amido pré-gelatinizado são os materiais mais adequados para a compressão direta de fármacos.

Excipients are widely used to formulate solid drug forms by direct compression. However, the powder-forming and tableting properties of these excipients are affected by the presence of lubricants and active ingredients. In this study, a screening methodology was employed to test the performance of an excipient for direct compression. The effects of three lubricants (magnesium stearate, stearic acid and talc) on the compressibility and compaction of these excipients were assessed by the compressibility index and lubricant sensitivity ratio, respectively. Likewise, the dilution potential in blends with a poorly compactible drug such as acetaminophen was also assessed. Finally, the elastic recovery of tablets was evaluated five days after production. All lubricants increased the compressibility of these excipients and improved their flowability. However, hydrophobic lubricants such as magnesium stearate had a marked negative effect on compactibility, especially in plastic-deforming and more regularly-shaped materials with a smooth surface such as Starch 1500. Alginic acid, rice and cassava starches had the largest elastic recovery (>5%), indicating a tendency to cap. Moreover, highly plastic deforming materials such as sorbitol and polyvinylpyrrolidone (PVP-K30) exhibited the best dilution potential (~10%), whereas alginic acid showed a very high value (~70%). In terms of performance, sorbitol, PVP-K30, Avicel PH-101, sodium alginate and pregelatinized starch were the most appropriate excipients for the direct compression of drugs.

Efeito antifúngico de tinturas de própolis e romã sobre espécies de Candida / Efecto antimicótico de las tinturas a partir de propóleo y pomegranate contra las especies de Candida / Antifungal effect of tinctures from propolis and pomegranate against species of Candida

A utilização de produtos naturais na odontologia tem se mostrado como uma fonte alternativa no combate às patologias orais, incluindo as infecções fúngicas, causadas, geralmente, por Candida spp. Avaliar a ação antifúngica de tinturas de própolis Apis milifera e romã Punica granatum sobre Candida albicans (ATCC 76618), Candida krusei (ATCC 6538) e Candida tropicalis (ATCC 13803). A ação antifúngica das tinturas foi avaliada pelo método da Concentração Inibitória Mínima em meio de cultura sólido Ágar Saburaud Dextrose (Difco®). Foram confeccionados poços, com 6 mm de diâmetro, destinados a inserção de 50 µL das tinturas. Foram avaliadas seis concentrações seriadas das tinturas, sendo a concentração inicial para a tintura de própolis 200 mg/mL e 300 mg/mL a concentração inicial para a tintura de romã. Posteriormente, as placas de Petri foram incubadas em estufa bacteriológica por 48 h a 37 ºC. A análise dos dados para a Concentração Inibitória Mínima foi feita através da mensuração dos halos de inibição, sendo considerados quando iguais ou superiores a 10 mm de diâmetro. Para a tintura de romã observou-se que as Concentração Inibitória Mínima sobre Candida albicans, Candida krusei e Candida tropicalis foram 9,37 mg/mL, 9,37 mg/mL e 18,75 mg/mL, respectivamente. Em relação à tintura da própolis, constatou-se que apenas em sua forma pura apresentou ação antifúngica sobre Candida krusei e Candida tropicalis, entretanto a mesma ação não foi observada sobre Candida albicans. As tinturas avaliadas apresentam ação antifúngica sobre as cepas avaliadas, exceto a tintura da própolis sobre Candida albicans(AU)

Se ha demostrado que el uso de productos naturales en Estomatología es una fuente alternativa contra las enfermedades orales, incluyendo las infecciones micóticas, generalmente causadas por Candida spp. El objetivo de este trabajo fue evaluar la acción antimicótica de las tinturas a partir del propóleo (Apis milifera) y a partir de pomegranate (Punica granatum) sobre Candida albicans (ATCC 76618), Candida krusei (ATCC 6538) y Candida tropicalis (TCC 13803). La actividad antimicótica de las tinturas fue evaluada por el método Minimum Inhibitory Concentration en Aagar Dextrosa Saburaud (Difco®). Se crearon 6 orificios con un diámetro de 6 mm para la inserción de 50 µL de tinturas. Se evaluaron 6 concentraciones seriadas donde la concentración inicial para las tinturas a partir de propóleo fue de 200 mg/mL y de 300 mg/mL como concentración inicial para la tintura a partir de pomegranate. Posteriormente, los discos de Petri fueron incubados durante 48 h a 37ºC. El análisis de los datos para Minimum Inhibitory Concentration fue realizado midiendo las zonas de inhibición, se consideró inhibición cuando es igual o mayor de 10 mm de diámetro. En el caso de la tintura de pomegranate, se comprobó que la Minimum Inhibitory Concentration en Candida albicans, Candida krusei y Candida tropicalis fueron de 9,37 mg/mL, 9,37 mg/mL y 18,75 mg/mL respectivamente. Para las tinturas a base de propóleo, la acción antimicótica fue verificada solo en la concentración pura sobre Candida krusei y Candida tropicalis, pero no fue observada en Candida albicans. Las tinturas a base de pomegranate y propóleo tuvieron actividad antimicótica sobre las cepas evaluadas, excepto en el caso de la tintura a base de propóleo sobre Candida albicans(AU)

The use of natural products in Dentistry has been shown as an alternative source against oral diseases, including fungi infections, generally caused by Candida spp. The aim was to evaluate the antifungal action of tinctures from propolis (Apis milifera) and from pomegranate (Punica granatum) on Candida albicans (ATCC 76618), Candida krusei (ATCC 6538) and Candida tropicalis (ATCC 13803). The antifungal activity of tinctures was evaluated by Minimum Inhibitory Concentration method on Saburaud Dextrose Agar (Difco®). Six wells were confectioned, with 6 mm of diameter, to the insertion of 50 µL of tinctures. Six serial concentrations were evaluated, been 200 mg/mL the initial concentration for tincture from propolis and 300 mg/mL the initial concentration for tincture from pomegranate. Later, the Petri plates were incubated in bacteriological incubator for 48 h on 37 ºC. Data analysis for Minimum Inhibitory Concentration was conducted by measurement of inhibition zones, been considered inhibited when equal or bigger than 10 mm of diameter. For tincture from pomegranate, was verified that the Minimum Inhibitory Concentration on Candida albicans, Candida krusei and Candida tropicalis were 9.37 mg/mL, 9.37 mg/mL and 18.75 mg/mL, respectively. For tinctures from propolis, the antifungal action was verified only in pure concentration on Candida krusei and Candida tropicalis, but it was not observed on Candida albicans. The tinctures from pomegranate and propolis had antifungal activity on evaluated strains, except for tincture from propolis on Candida albicans(AU)

Evaluation of the physicochemical characteristics of crospovidone that influence solid dispersion preparation.

A solid dispersion (SD) powder of indomethacin (IM) with crospovidone (CrosPVP) shows useful characteristics for manufacturing dosage forms. Four types of commercial CroPVP, Polyplasdone XL (XL) used as the initial carrier, Polyplasdone XL10 and INF-10 manufactured by milling XL, and Kollidon CL (CL) marketed by another company, were compared. The limit of the IM-CrosPVP weight ratio with which an SD can be prepared (maximum IM content) was calculated on the basis of the heat of fusion of physical mixtures of IM and CrosPVP with various weight ratios. When Polyplasdones were used, the maximum IM content increased with the specific surface area of the CrosPVP. When CL was used, however, it was about half of that obtained with XL, even though the difference between XL and CL was not observed in the physicochemical characteristics (particle size, specific surface area, flowability, glass transition temperature, IR spectra, and solid state NMR spectra). As determined by pore size distribution measurement, the volume of pore of which size is larger than the particle size of IM was less in CL than in XL. Therefore, the effective surface area of CrosPVP that comes in contact with IM is important for the preparation of the SD.

Applying spectral peak area analysis in near-infrared spectroscopy moisture assays.

Spectral peak area analysis has in this study been shown to be a viable method in near-infrared spectroscopy (NIRS) moisture assays. The study also shows that the required number of calibration samples can be minimized, and the method is, therefore, especially suitable for moisture assays in early formulation development and in-situ process monitoring. Diffuse NIRS was utilized in the development of moisture assays for the model compounds polyvinylpyrrolidone and hydroxypropyl-beta-cyclodextrin and also for a lyophilized formulation. Reference data were obtained using coulometric Karl Fischer titration. The NIRS measurements were performed through the bottoms of the sample vials using either a Fourier Transform-Near-Infrared (FT-NIR) spectrometer fitted with a diffuse reflectance probe or a dispersive single beam spectrometer. The ratios of the peak areas of a water peak at 5200 cm(-1) and a reference peak were evaluated using linear regression analysis. The spectral peak area analysis method was compared with a conventional partial least squares regression method. The moisture assays were verified using independent test sets. The investigated moisture range was 0-22% for the samples of PVP, 0-8.5% for the samples of hydroxypropyl-beta-cyclodextrin and 0.5-8.5% for the samples of the lyophilized formulation. The results of the spectral peak area analysis and the conventional partial least squares regression were similar, but the peak area method was more robust and could also make accurate predictions for lyophilized PVP samples, although the calibration set consisted of non-lyophilized samples. The peak area method required fewer calibration samples than the conventional partial least squares regression method.

Allergic contact dermatitis to copolymers in cosmetics--case report and review of the literature.

Copolymers or heteropolymers are large molecules with high molecular weights (>1000 D). They have been underestimated for a long time as to their sensitizing capacities. Allergic contact dermatitis to 6 copolymers in cosmetics and 1 in a medical dressing has been described; however, the nature of the hapten is still unknown. We report a case of allergic contact dermatitis to polyvinylpyrrolidone (PVP)/hexadecene copolymer in a purple-colored lipstick and review the literature on allergic contact dermatitis to 7 copolymers: PVP/hexadecene, PVP/eicosene, PVP/1-triacontene, methoxy polyethyleneglycol (PEG)-22/dodecyl glycols, methoxy PEG-17/dodecyl glycols, phthalic anhydride/trimellitic anhydride/glycols, and polyvinyl methyl/maleic acid anhydride.

Excipientes de medicamentos e as informações da bula / Pharmaceutical excipients and the information on drug labels

OBJETIVO: Avaliar a presença de conservantes, corantes, adoçantes e aromatizantes em 73 apresentações farmacêuticas de 35 medicamentos para uso oral, e as informações da bula sobre excipientes. MÉTODOS: Selecionamos 35 medicamentos, de venda livre ou sob prescrição médica, comercializados no Brasil. A amostra incluiu: analgésicos/antitérmicos, antimicrobianos, mucolíticos, antitussígenos, descongestionantes, anti-histamínicos, broncodilatadores, corticosteróides, antiinflamatórios e suplementos vitamínicos. Foram analisadas 73 apresentações desses fármacos, anotando-se as informações da bula sobre conservantes, corantes, adoçantes e aromatizantes. RESULTADOS: A bula de um medicamento (1,3 por cento) não mencionava os ingredientes inativos. Os conservantes mais encontrados nos medicamentos foram metilparabeno e propilparabeno (43 por cento e 35,6 por cento respectivamente). Os adoçantes mais usados foram: sacarose (açúcar) (53,4 por cento), sacarina sódica (38,3 por cento) e sorbitol (36,9 por cento). Vinte e um produtos (28,7 por cento) continham dois adoçantes. Predominaram os medicamentos sem corante (43,8 por cento), seguidos pelos coloridos por amarelo crepúsculo (amarelo FD&C no. 6) (15 por cento). Cinco produtos (6,8 por cento) continham mais de um corante. A tartrazina (amarelo FD&C no. 5) foi encontrada em sete formulações (9,5 por cento). Os aromatizantes mais usados foram os de frutas (83 por cento). Constatamos a freqüente omissão das bulas sobre o teor exato de açúcar dos produtos (77 por cento). Duas das quatro bulas de medicamentos contendo aspartame não mencionavam as precauções no uso por fenilcetonúricos. CONCLUSÕES: A omissão e a imprecisão das informações da bula sobre os excipientes farmacêuticos expõem os indivíduos suscetíveis ao risco de reações adversas dos conservantes e corantes. Também podem ocorrer complicações do uso inadvertido de medicamentos contendo açúcar pelos pacientes diabéticos, ou de fármacos adoçados com aspartame pelos fenilcetonúricos.

AIM: to evaluate the presence of preservatives, dyes, sweeteners and flavouring substances in 73 pharmaceutical preparations of 35 medicines for oral administration, according to drug labeling information about the excipients. METHODS: 35 medications were selected, both over-the-counter and prescription durgs, marketed in Brazil. The sample included: analgesic/antipyretic, antimicrobial, mucoregulatory, cough and cold, decongestant, antihistamine, bronchodilator, corticosteroid, antiinflammatory and vitamin medications. We collected data on 73 preparations of these drugs, according to drug labeling information regarding preservatives, dyes, sweeteners and flavourings. RESULTS: Methylparaben and propylparaben were the most common preservatives found (43 percent and 35.6 percent respectively). The most common sweeteners were: sucrose (sugar) (53.4 percent), sodium saccharin (38.3 percent) and sorbitol (36.9 percent). Twenty-one medicines (28,7 percent) contained two sweeteners. Colourless medicines predominated (43.8 percent), followed by those with sunset yellow dye (FD&C yellow no. 6) (15 percent). Five products (6.8 percent) contained more than one colour agent. Tartrazine (FD&C yellow no. 5) was present in seven preparations (9.5 percent). Fruit was the most common flavouring found (83 percent). Labelings of drugs which contained sugar frequently omitted its exact concentration (77 percent). Of the four labelings of medicines which contained aspartame, two did not warn patients regarding phenylketonuria. CONCLUSION: Omission and inacuracy of drug labeling information on pharmaceutical excipients may expose susceptible individuals to adverse reactions caused by preservatives and dyes. Complications of inadvertent intake of sugar-containing medicines by diabetics, or aspartame intake by patients with phenylketonuria may also occur.

Excipientes farmacêuticos: perspectivas dos polissacarídeos na pesquisa e desenvolvimento de novos sistemas de liberação / Pharmaceutical excipients: perspectives for polysaccharides in the research and development of new drug delivery systems

Excipientes em geral são conceituados como substâncias auxiliares diretamente envolvidas na composição das diversas formulações farmacêuticas. Constituintes de diferentes sistemas terapêuticos viabilizam o sucesso da forma farmacêutica final, apresentando características e propriedades diferentes daquelas pertinentes aos fármacos. Excipientes farmacêuticos constituem elementos de elevado destaque na formulação dos medicamentos, uma vez que, exercem efetivo papel na garantia de obtenção da forma farmacêutica adequada ao uso e ao efeito terapêutico desejado, regendo e influenciando de maneira significativa a cedência do princípio ativo contido no medicamento. Polissacarídeos são polímeros de monossacarídeos, encontrados abundantemente na natureza, a baixo custo, e devido as suas propriedades, de baixa toxicidade, biodegradabilidade, características filmogênicas, facilidade de derivatização, disponibilidade a baixo custo, têm constituído elementos de elevado interesse e destaque nas pesquisas farmacêuticas. Estes polímeros naturais encontram vasto campo de aplicação incluindo a melhoria de diversas propriedades das formulações de formas farmacêuticas sólidas tradicionais, sendo estas representadas pela facilidade de escoamento dos granulados, boa uniformidade de peso e otimização da dureza em comprimidos. Prioritariamente, encontram posição de destaque na pesquisa e desenvolvimento de novos sistemas para liberação modificada de fármacos quando aplicados nos sistemas reservatórios (revestimento farmacêutico), sistemas matriciais, ou como ôcarregadoresö macromoleculares e/ou biodegradáveis

Análise térmica - Princípios, aplicaçöes e importância em fármaco e medicamentos / Thermal Analysis - Principles, applications and relevance in drug and medicaments

Os métodos termoanalíticos permitem medir as mudanças de uma propriedade física ou química de um material, em conseqüência da temperatura. Mediante a análise térmica é possível avaliar a pureza, polimorfismo, incompatibilidades entre fármaco/fármaco, fármaco/excipientes, além de predizer a estabilidade de uma formulaçäo (Venkataram et al., 1995; Matos et al., 1998; Peres Del Comune, 1999).

Qualitative determination of polyvinylpyrrolidone type by near-infrared spectrometry.

Soluble polyvinylpyrrolidones are very useful and versatile pharmaceutical auxiliaries. The different types of povidone are characterised by their viscosity measured in water, expressed as a K-value. We have developed a rapid, accurate, reliable, and non-destructive near infrared (NIR) spectroscopy method for the determination of PVP type and consequently identification thereof. We have implemented chemometrics onto NIR spectra collected in diffuse reflectance mode using fibre optics to build a qualitative model that enables us to obtain useful analytical information. A principal component analysis and a modelling technique soft independent modelling of class analogy (SIMCA) were applied. An approach to validate the method was developed.

Fatty acid composition of beef, pork, and poultry fresh cuts, and some of their processed products

Numerous researchers have shown that dietary fats and oils may affect blood lipid levels and the development of cardiovascular diseases, but consumers are receiving mixed messages about the percentage of fat they should consume in their diets, and they can make proper food choices only when they have the right information. Fatty acid profiles of the meat food products in the Venezuelan diet were determined. Methyl esters were analyzed by gas chromatography on a PT 10 per cent Silar-10C on Gas-Chrom Q 100/120 mesh column. Beef cuts presented a predominant presence of oleic acid (36.21 per cent), palmitic (25.67 per cent) and stearic (20.97). Oleic and palmitic acids are present in pork meat at 42.83 and 24.15 per cent respectively; with lesser quantities of stearic and higher amounts of linoleic acid than beef. Poultry products showed a high content of linoleic (19.54 per cent) and low content of stearic (8.22 per cent) acids. Pork, poultry products, and beef liver presented a considerable amount of linoleic acid 11.85 per cent, 19.54 per cent, and 12.09 per cent, respectively.

Estudos da estabilidade quimica e da absorcao "in vivo" da vitamina A em preparacoes cosmeticas para a pele / Stability chemical studies and the absorption \"in vivo\" of the vitamin A in cosmetics preparations for skin

A vitamina A tem sido muito usada em cosmeticos em funcao de suas propriedades farmacodinamicas. Atua na pele, mantendo-a em bom estado e favorecendo seu matabolismo correto. Atua sobre a epitelizacao em peles secas e asperas, bem como em ceratinizacoes consideradas anormais. A vitamina A e instavel frente ao oxigenio atmosferico e a luz, sendo de fundamental importancia a realizacao de testes de estabilidade quimica em preparacoes cosmeticas que a contem. A penetracao na pele e exigencia essencial para muitos dos efeitos biologicos das vitaminas na area de cosmeticos e principalmente em aplicacoes dermatologicas. A estabilidade e a absorcao da vitamina A na pele e influenciada pelo tipo de preparacao usada como veiculo. Assim sendo, os objetivos desta pesquisa foram investigar um veiculo que permitisse boa absorcao da vitamina A na pele e tambem a realizacao de testes de estabilidade quimica desta vitamina em preparacoes cosmeticas para pele objetivando sugerir o emprego de formulacoes (veiculos) que apresentem maior estabilidade quanto a vitamina A. O estudo foi realizado em diferentes veiculos, tais como: emulsoes O/A, A/O, gel hidrofilico e formulacoes compostas por esteres fosforicos. Os resultados obtidos confirmaram a influencia do veiculo na estabilidade e absorcao da vitamina A nas formulacoes estudadas, sendo que as preparacoes que apresentaram a melhor absorcao cutanea para a vitamina A foram as formulacoes que continham esteres fosforicos e a preparacao que proporcionou a melhor estabilidade para a vitamina A foi a emulsao A/O

[The determination of ethylene glycol in biological objects in the presence of propylene glycol]. / Opredelenie étilenglikolia v biologicheskikh ob''ektakh v prisutstvii propilenglikolia.

Therapeutic application of drugs containing propylene glycol 1.2 as a solvent may distort the results of forensic chemical detection of ethylene glycol from its oxidation products. Practical examples illustrate the possibility of ethylene glycol determination by gas chromatography in the presence of propylene glycol.

Retention of preservative levels of formaldehyde in desiccated biological products.

Concentrations ranging from 8 to 100% of the preservative level of formalin (37% formaldehyde solution) were retained by desiccated biologics, with most products retaining about 50% regardless of the amount originally present.