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We investigated a spray drying process for preparing water-soluble salts of high molecular weight chitosan (CH) intended for pharmaceutical excipient applications. CH was derived from chitin of marine lobster origin (Panulirus argus). The effects of organic acid (acetic or lactic acid) and the ratio (difference) of inlet/outlet air temperature (140/90 °C or 160/100 °C) on spray drying were studied. The yield of spray-dried CH salt powders ranged from 50% to 99% in laboratory and industrial-scale processes. The spray-dried dry powder of CH salts consisted of spherical agglomerated particles with an average diameter of 36.2 ± 7.0 µm (CH acetate) and 108.6 ± 11.5 µm (CH lactate). After dispersing the spray-dried CH salt powder samples in purified water, the mean particle sizes obtained for the CH acetate salts were 31.4 nm (batch A001), 33.0 nm (A002) and 44.2 nm (A003), and for the CH lactate salts 100.8 nm (batch L001), 103.2 nm (L002) and 121.8 nm (L003). The optimum process conditions for spray drying were found: an inlet air temperature of 160 ± 5 °C, an outlet temperature of 100 ± 5 °C and an atomizer disk rotational speed of 18,200 min−1. The X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC) results confirmed the amorphous state of the CH salts. The 1H nuclear magnetic resonance (NMR) and Fourier transform infrared (FT-IR) spectra of CH acetate and lactate salts verified that the spray drying process does not affect the polymer backbone. In conclusion, both laboratory and industrial-scale spray drying methods for preparing water-soluble acid salts of CH are reproducible, and the physicochemical properties of the corresponding CH acid salts are uniform.

This study assessed the effect of molecular weight (MW) reduction by gamma irradiation on the antioxidant capacity of chitosan with potential application in the preservation of foodstuffs. Two batches of chitosan were obtained by heterogeneous chemical N-deacetylation of chitin from common lobster (Panulirus argus). Irradiation of chitosan was performed using a 60Co source and applying doses of 5, 10, 20 and 50 kGy with a dose rate of 10 kGy/h. Attenuated Total Reflection Fourier Transform Infrared Spectroscopy was used to identify main chemical features of chitosan. The average viscosimetric MW was determined by the viscosimetric method while the deacetylation degree by a potentiometric method. Thermogravimetric analysis and differential scanning calorimetry were conducted to evaluate the thermal degradation behavior of the chitosan samples, both under nitrogen flow. The antioxidant activity of chitosan solutions at 1% (w/v) in lactic acid at 1% (v/v) and Tween 80 at 0.1% (v/v) was evaluated through the ABTS assay and scavenging of DPPH radical by chitosan. The increase of irradiation dose with 60Co until 50 kGy decreased significantly the MW of chitosan through the scission of glycosidic bonds without affecting its functional groups, while the DD (72–75 %) did not vary (p > 0.05). The AC of the chitosan solutions increased with the reduction of MW of chitosan by gamma irradiation.

The effects of spray-drying process and acidic solvent system on physicochemical properties of chitosan salts were investigated. Chitosan used in spray dryings was obtained by deacetylation of chitin from lobster (Panulirus argus) origin. The chitosan acid salts were prepared in a laboratory-scale spray drier, and organic acetic acid, lactic acid, and citric acid were used as solvents in the process. The physicochemical properties of chitosan salts were investigated by means of solid-state CP-MAS (13)C nuclear magnetic resonance (NMR), X-ray powder diffraction (XRPD), differential scanning calorimetry, and Fourier transform infrared spectrometry (FTIR) and near-infrared spectroscopy. The morphology of spray-dried chitosan acid salts showed tendency toward higher sphericity when higher temperatures in a spray-drying process were applied. Analysis by XRPD indicated that all chitosan acid salts studied were amorphous solids. Solid-state (13)C NMR spectra revealed the evidence of the partial conversion of chitosan acetate to chitin and also conversion to acetyl amide form which appears to be dependent on the spray-drying process. The FTIR spectra suggested that the organic acids applied in spray drying may interact with chitosan at the position of amino groups to form chitosan salts. With all three chitosan acid salts, the FTIR bands at 1,597 and 1,615 cm(-1) were diminished suggesting that -NH groups are protonated. The FTIR spectra of all chitosan acid salts exhibited ammonium and carboxylate bands at 1,630 and 1,556 cm(-1), respectively. In conclusion, spray drying is a potential method of preparing acid salts from chitosan obtained by deacetylation of chitin from lobster (P. argus) origin.

En el presente trabajo se realizó el estudio de estabilidad de las gotas nasales de efedrina. Primero se evaluó la influencia de los agentes preservantes demostrándose la incompatibilidad del clorhidrato de efedrina y el clorobutanol, por lo que fue seleccionada la combinación de cloruro de benzalconio y edetato disódico con excelentes resultados en la efectividad de preservos. Se elaboraron tres lotes pilotos de la formulación y se les realizó los estudios de estabilidad por el método acelerado y de vida de estante, respectivamente. Durante los seis meses (estabilidad acelerada) y hasta los 24 meses (vida útil) las características organolépticas cumplieron con las especificaciones establecidas. El pH del medio se comportó de manera estable cumpliendo con los límites establecidos. El principio activo no alcanzó una degradación mayor al 5%, mostrando buena estabilidad. La concentración de los preservos cumplió con los parámetros, así como el conteo microbiano del producto terminado. La formulación envasada en frascos de vidrio ámbar de calidad hidrolítica III, de capacidad nominal 15 mL con tapa de polipropileno de 18 mm y gotero interior de polietileno de alta densidad, mostró adecuada estabilidad física, química y microbiológica durante 24 meses.

Aim: The objective of this work was to develop and validate a method for determining the degree of molar deacetylation of chitosan acetate and chitosan lactate, as well as to study the stability of both salts. Materials and Methods: A spectrophotometric method was validated according to internationally-established quantitative techniques. Three industrial batches of chitosan acetate and chitosan lactate, obtained by spray drying, were stored under shelf life conditions for twelve months. Organoleptic characteristics, the degree of molar deacetylation, pH, loss on drying and microbiological count were determined at the beginning and end of the study. Results and Discussion: The statistical data proved that the two methods complied with international standards for the validation of analytical techniques. It was shown that the procedures developed were linear, specific, precise and accurate, so they can be used for the purposes of quality control and stability study of the polymer salts. Salts remained in powder form, with a light-yellow to dark-yellow coloration. Values of loss on drying (2.5 - 5.2 %) of chitosan salt using acetic or lactic acid, as a solvent, indicated the good quality of spray-dried particles of chitosan. Similar behavior was obtained regarding pH. The two salts stayed within the parameters that determine their quality, both in the initial stage and after twelve months at room temperature. Conclusion: Spray drying chitosan acetate and chitosan lactate, stored at room temperature in a dry place, in double polyethylene bags and multilayer paper bags, kept their physical, chemical and microbiological characteristics for a period of twelve months.

Se estudió el comportamiento reológico de la jalea dentífrica fluida mediante el empleo de un rotoviscosímetro digital HAAKE y se determinó la viscosidad aparente con la utilización de un viscosímetro rotatorio Brookfield modelo RVF. La preparación se almacenó a diferentes condiciones térmicas. Se analizaron los resultados estadísticamente a través de un análisis de varianza para contrastar si existen diferencias significativas entre las medias de las poblaciones. Tras el estudio reológico se pudo llegar al criterio de que corresponde su comportamiento a un cuerpo con flujo no newtoniano pseudoplástico, con un buen grado de recuperación estructural. No se encontraron diferencias estadísticamente significativas con un nivel de confiabilidad del 95 % entre los valores de las medias de la viscosidad aparente de la preparación almacenada a diferentes temperaturas durante 48 semanas después de elaborada. La formulación diseñada resultó estable físicamente, al menos, bajo las condiciones y circunstancias experimentales en que se ha ensayado.The rheologic behavior of the fluid tooth gel was studied by using a HAAKE digital rotatory viscosimeter. The apparent viscosity was determined by a Brookfield RVF rotatory viscosimeter. The preparation was stored under different thermal conditions. The results were statistically analyzed through a variance analysis to know if there were significant differences among the means of the population. According to the rheologic study, it was concluded that its behavior corresponded to a body with non Newtonian pseudoplastic flow, with a good degree of structural recovery. Statistically significant differences were not found. A reliability level of 95 % was attained among the values of the means of the apparent viscosity of the preparation stored at different temperatures during 48 weeks after being made. The designed formulation proved to be physically stable, at least under the experimental conditions and circunstances used in this trial.

Se empleó el método de prueba y error para el desarrollo de la formulación de la suspensión oral de ibuprofeno 100 mg/5 mL para uso pediátrico; se estudió su estabilidad químico-física por el método acelerado y de vida de estante; se envasó en frasco de vidrio ámbar por 120 mL y se almacenó a temperatura ambiente. Se realizó el estudio reológico y la determinación de la viscosidad aparente, además, se efectuó el estudio microbiológico a través de la prueba de efectividad de preservativo antimicrobiano y el conteo microbiano; se comprobó la seguridad del producto mediante el estudio toxicológico. Todos los resultados cumplieron con los límites de calidad establecidos en la literatura científica, USP 30, para este tipo de forma farmacéutica. Se concluye que el medicamento desarrollado está correctamente formulado, desde el punto de vista galénico con un tiempo de vida útil de 24 meses bajo las condiciones estudiadas.Authors used the test and error method to develop the formulation of Ibuprofen oral suspension (100 mg/5 mL) for pediatric use. Its chemical-physic stability was studied through accelerated method and shelf life. It was bottled in amber glass small bottles by 120 mL, and it was stored at room temperature. A rheology study and assessment of apparent viscosity was made as well as a microbiologic one by test of effectiveness of antimicrobial preservative and the microbial count. Product safe was verified by toxicology study. All results fulfilled quality limits established in scientific literature, USP 30, for this type of pharmaceutical method. We conclude that drug developed is correctly formulated, from the doctoral point of view with a time of useful life of 24 months under study conditions.

La celulosa microcristalina ha sido usada recientemente en el tratamiento de la gastritis alcalina por reflujo biliar duodenogástrico. Se realizó un estudio toxicológico y se evaluó el efecto antiulceroso de celulosa microcristalina suspensión al 12 % en ratas. La determinación de la toxicidad aguda oral se realizó mediante el ensayo de dosis límite, mediante la administración de una dosis de 2 000 mg/kg a animales de uno y otro sexos. El efecto protector sobre la mucosa gástrica se evaluó sobre lesiones inducidas por taurocolato de sodio y se ensayaron las dosis de 240, 360 y 540 mg/kg de la suspensión. Como resultado en el estudio toxicológico, no se produjo mortalidad para la dosis ensayada, por lo que se clasificó la sustancia como no tóxica. Mientras que las diferentes dosis empleadas para el efecto antiulceroso disminuyeron el número y la intensidad de las lesiones significativamente de manera dosis dependiente. La dosis efectiva media fue de 356,8 mg/kg. Tales hallazgos permiten sugerir que el efecto protector de celulosa microcristalina suspensión al 12 % podría estar dado por una inactivación de los ácidos biliares o por una alteración en la cantidad o composición de la capa de moco que recubre la mucosa gástrica.The microcrystalline cellulose has been used recently in the treatment of alkaline gastritis due to duodenogastric biliary reflux. A toxicological study was conducted and the antiulcer effect of microcrystalline cellulose suspension 12 % was evaluated in rats. Acute oral toxicity was determined by the limited dose test through the administration of a dose of 2 000 mg/kg to animals of both sexes. The protective effect over the gastric mucosa was evaluated in the injuries induced by sodium taurocholate. Doses of 240, 360 and 540 mg/kg of the suspension were tested. As a result, no mortality was reported for the tested dose in the toxicological study. Therefore, the substance was clasiffied as non toxic. The different doses used for the antiulcer effect reduced significantly the number and intensity of the injuries depending on the dose. The mean effective dose was 356.8 mg/kg. These findings allowed to suggest that the protective effect microcrystalline cellulose suspension 12 % could be given by an inactivation of the biliary acids or by an alteration in the quantity or composition of the layer of mucus covering the gastric mucosa.

La celulosa microcristalina ha sido usada recientemente en el tratamiento de la gastritis alcalina por reflujo biliar duodenogástrico. Se realizó un estudio toxicológico y se evaluó el efecto antiulceroso de celulosa microcristalina suspensión al 12 % en ratas. La determinación de la toxicidad aguda oral se realizó mediante el ensayo de dosis límite, mediante la administración de una dosis de 2 000 mg/kg a animales de uno y otro sexos. El efecto protector sobre la mucosa gástrica se evaluó sobre lesiones inducidas por taurocolato de sodio y se ensayaron las dosis de 240, 360 y 540 mg/kg de la suspensión. Como resultado en el estudio toxicológico, no se produjo mortalidad para la dosis ensayada, por lo que se clasificó la sustancia como no tóxica. Mientras que las diferentes dosis empleadas para el efecto antiulceroso disminuyeron el número y la intensidad de las lesiones significativamente de manera dosis dependiente. La dosis efectiva media fue de 356,8 mg/kg. Tales hallazgos permiten sugerir que el efecto protector de celulosa microcristalina suspensión al 12 % podría estar dado por una inactivación de los ácidos biliares o por una alteración en la cantidad o composición de la capa de moco que recubre la mucosa gástrica.