Physicochemical and antimicrobial evaluation of chitosan and hydroxypropyl methylcellulose films forprolonged release of pilocarpine / Evaluación fisico-química y antimicrobiana de biopelículas de quitosán e hidroxipropilmetilcelulosa para liberación prolongada de pilocarpina

The use of prolonged local drug delivery to the oral cavity offers multiple benefits, such as increasing the pharmacological action in the desirable local site and reducing the usual dose and the adverse effects. Pilocarpine is a cholinergic drug approved by the FDA for the treatment of glandular hypofunction; however, the extent of its adverse effects limits its use. Objective: The main aim of this study was to analyze the physical and chemical properties of films, including pH, thickness, solubility, consistency and the ability to release pilocarpine for a prolonged time. Additionally, theantimicrobial activity in two opportunistic pathogens in hyposialia (Streptococcus mutans and Candida albicans) was also assessed. Methodology: Chitosan and HPMC (Methocel K4M CR) films were prepared in 1 percent acetic acid and pilocarpine was added under magnetic stirring. PH, thickness and time of solubility in artificial saliva, as well as diffusion and drug release kinetics per cm2 (OD=420nm) were assessed by spectrophotometry. The antimicrobialactivity was tested by disk diffusion test against St. mutans ATCC 700610 and C. albicans ATCC 90029 at concentrations of hyposalivation (1.44x1.2x106 CFU and 103 CFU, respectively). Results: All the films, except for Hydroxypropyl methylcellulose / Pilocarpine formulation, were found to have optimal physical-chemical properties for handling, maintaining drug diffusion in 76 percent per cm2 for four hours extended-release without showing antimicrobial activity at concentrations of hyposalivation. Conclusion: The films had optimum handling properties and a constant drug release; however, antimicrobial activity was not found...

El uso local de administración prolongada de fármacos en la cavidad oral proporciona múltiples ventajas, aumentando la acción farmacológica en el sitio local deseable, reducción de la dosis usual y disminución de los efectos adversos. La pilocarpina es una droga colinérgica aprobada por la FDA para el tratamiento de la hipofunción glandular, sin embargo la amplitud de sus efectos adversos limitan su uso. Objetivo: Con el objetivo de analizar las propiedades físico-químicas de las biopelículas se evaluó el pH, grosor, solubilidad, uniformidad y la capacidad de liberar prolongadamente pilocarpina, así como su actividad antimicrobiana ante los dos microorganismos patógenos oportunistas en la hiposialia (Streptococcus mutans y Candida albicans). Metodología: Se elaboraron biopelículas de Quitosán e Hidroxipropilmetilcelulosa (Methocel K4MCR) en ácido acético al 1 por ciento, adicionadas con pilocarpina bajo agitación magnética, evaluando el pH, grosor y el tiempo de solubilidad en saliva artificial, así como la uniformidad de difusión y cinética de liberación de la droga por cm2 mediante espectrofotometría (OD=420nm). Mediante difusión en disco se evaluó la actividad antimicrobiana ante Streptococcus mutans ATCC 700610 y Candida albicans ATCC 90029 en concentraciones encontradas en hiposalivación (1.44 x 106 UFC y 1.2 x 103 UFC respectivamente). Resultados: Todas las biopelículas, a excepción de la formulación Hidroxipropilmetilcelulosa e Hidroxipropilmetilcelulosa/ Pilocarpina resultaron tener las propiedades físico-químicas óptimas de manipulación, manteniendo una uniformidad de difusión de la droga en 76 por ciento por cm2 con liberación prolongada por 4 horas, sin mostrar actividad antimicrobiana en concentraciones de hiposalivación. Conclusión: Las películas obtuvieron las propiedades óptimas de manipulación, y una constante liberación del fármaco, sin embargo, ninguna formulación presentó actividad antimicrobiana...

Caracterización cinética de la respuesta de secreción salival producida por ácido cítrico: diferencias con pilocarpina / Kinetic assessment of salivary secretory response to citric acid, as compared with pilocarpine

Background: Induction of salivation is becoming increasingly popular in the assessment of salivary gland status. Various mechanical or pharmacological procedures are empirically used to produce salivation. Oral stimulation by citric acid (AC) is by far the most used sialagogue procedure. Aim: To characterize the salivary secretory response to AC solutions applied to the dorsolateral tongue surfaces. Subjects and methods: Young healthy women from the upper levels of a medical career (n=19) participated as volunteers. Salivary volume and UV-absorbing organic material in saliva from single subjects were measured after various protocols of topical stimulation by AC. Results: After a single stimulation by 1-8 percent AC the salivary flow rate peaked before 30 seconds and recovered the basal level earlier than 2 minutes. Repetitive stimulations at 30-sec intervals kept the flow rate at a maximum. After suspending these stimulations, basal flow rate was recovered before 2 minutes. Repetitive AC-stimulations at 8-min intervals produced a series of identical and independent secretory responses. The concentration of organic material in saliva remained unaltered after the various modes of stimulation. Thus, the profile of organic material secretion was always a direct expression of changes in salivary flow rate. In contrast to AC, the oral administration of the cholinergic agonist pilocarpine (PIL) produced a two-wave salivary response that as a whole lasted for about 30 minutes. In this case the volume and the amount of organic material were at least 10-fold the ones secreted in response to AC. Conclusions: AC provoked a rapid and short-lived salivary response that differs markedly from the one produced by other secretagogues, like pilocarpine

Ultrasonic study to see the effect of topical pilocarpine and homatropine on anterior chamber depth in phakic cases.

Pilocarpine and Homatropine are the drugs having known effect on the depth of anterior chamber. The purpose of this study was to demonstrate the time of onset, peak effect and its duration of action as well as shallowing/deepening of the anterior chamber, after single instillation of pilocarpine 2% or homatropine bromide 2%, topically in one eye. Also we tried to see if there is any effect on the contralateral eye, due to systemic absorption of pilocarpine, homatropine after topical instillation of the drug in one eye. Pilocarpine causes a measurable shallowing of the anterior chamber with onset of effect with in 20 minutes and a peak in 60 minutes, the average narrowing being 0.26 mm. (range 0.20-0.29 mm.). Homatropine has a measurable deepening effect on the anterior chamber, due to axial flattening of the lens because of cycloplegia, with a range of 0.33 to 0.36 mm. In 70% of the cases the effect passes away with in 24 hours., but in 30% it comes to normal in 48 hours.