Inhalation powder development without carrier: How to engineer ultra-flying microparticles?

Particle engineering technologies have led to the commercialization of new inhaled powders like PulmoSolTM or PulmoSphereTM. Such platforms are produced by spray drying, a well-known process popular for its versatility, thanks to wide-ranging working parameters. Whereas these powders contain a high drug-loading, we have studied a low-dose case, in optimizing the production of powders with two anti-asthmatic drugs, budesonide and formoterol. Using a Design of Experiments approach, 27 powders were produced, with varying excipient mixes (cyclodextrins, raffinose and maltodextrins), solution concentrations, and spray drying parameters in order to maximize deep lung deposition, measured through fine particle fraction (next generation impactor). Based on statistical analysis, two powders made of hydropropyl-ß-cyclodextrin alone or mixed with raffinose and L-leucine were selected. Indeed, the two powders demonstrated very high fine particle fraction (>55%), considerably better than commercially available products. Deep lung deposition has been correlated to very fine particle size and lower microparticles interactions shown by laser diffraction assays at different working pressures, and particle morphometry. Moreover, the two drugs would be predicted to deposit homogeneously into the lung according to impaction studies. Uniform delivery is fundamental to control symptoms of asthma. In this study, we develop carrier-free inhalation powders promoting very efficient lung deposition and demonstrate the high impact of inter-particular interactions intensity on their aerosolization behaviour.

Engineered-inhaled particles: Influence of carbohydrates excipients nature on powder properties and behavior.

Pulmonary drug administration has long been used for local or systemic treatment due to several advantages. Dry powder inhalers emerge as the most promising due to efficiency, ecologic, and drug stability concerns. Coarse lactose-carrier is still the gold standard when inhalation powders are developed. Despite some efforts to produce new types of powders, the lung drug deposition is still poorly controlled, which will ultimately impact therapeutic effectiveness. In this study, we developed "engineered-inhalation powders" using the spray-drying technique. Multiple carbohydrates excipients were binary mixed and combined with two active pharmaceutical ingredients for asthma therapy (budesonide and formoterol). Particle morphology, from spherical to deflated shapes, was characterized by the number and the depth of dimples measured from SEM images. We define a new characteristic deflation ratio ξ as the product between the number of dimples and their depth. Six different powders having opposite morphologies have been selected and we have demonstrated a linear correlation between the fine particle fraction and the deflation ratio of produced powders. Overall, we showed first that the morphology of inhalable powder can be finely tuned by spray-drying technique when excipients varied. Secondly, we developed stable inhalation powders that simultaneously induced high fine particle fractions (>40%) for two drugs due to their deflated surface. The stability has been evaluated for up to 2 months at room temperature.

Scaling behavior of particle breakage in granular flows inside rotating drums.

We perform systematic particle dynamics simulations of granular flows composed of breakable particles in a 2D rotating drum to investigate the evolution of the mean particle size and specific surface as a function of system parameters such as drum size, rotation speed, filling degree, and particle shape and size. The specific surface increases at a nearly constant rate up to a point where particle breakage begins to slow down. The rates of particle breakage for all values of system parameters are found to collapse on a master curve when the times are scaled by the characteristic time defined in the linear regime. We determine the characteristic time as a function of all system parameters, and we show that the rate of particle breakage can be expressed as a linear function of a general scaling parameter that incorporates all our system parameters. This scaling behavior provides a general framework for the upscaling of drum grinding process from laboratory to industrial scale.

Histoplasmosis diseminada progresiva en una cohorte de pacientes coinfectados con el VIH / Progressive disseminated histoplasmosis in a cohort of patients with HIV coinfection

Objetivo: identificar manifestaciones clínicas y métodos de laboratorio conducentes al diagnóstico de histoplasmosis diseminada progresiva (HDP), en una cohorte de pacientes coinfectados con el VIH. Diseño: análisis retrospectivo de historias clínicas. No intervención adicional. Pacientes: cuarenta pacientes con HDP e infección por VIH del Hospital La María, enero de 1992 a diciembre de 2008. Mediciones: datos demográficos, signos, síntomas y exámenes de laboratorio que permitieron el diagnóstico de HDP. Resultados: cuarenta pacientes, 34 hombres (85%), y seis mujeres (15%), con edades promedio de 33.4 y 27 años, respectivamente. En éstos predominaron: tos (77.5%), fiebre (90%) y anorexia con pérdida de peso en 92.5% y 77.4%, respectivamente. Lesiones en piel en 55% y en mucosa en 50%, crecimiento ganglionar en 62.5% y hepatomegalia en 52.5%. Menos frecuentes fueron disnea, esplenomegalia, vómito, diarrea y cefalea. Presentaron anemia el 85%, leucopenia el 52.5% y trombocitopenia el 30% de los pacientes. Exámenes micológicos: directo positivo en 21 muestras, de lavado broncoalveolar siete, piel seis, ganglio 12, biopsia transbronquial una y lesión de mucosa una. Se aisló H. capsulatum en todos los pacientes a partir de muestras de piel 10, ganglio 18, sangre tres, médula ósea una, lavado broncoalveolar (LBA) 10, y mucosa tres. Además, en siete pacientes, el hongo se aisló de más de un sitio anatómico. La serología realizada en 13 pacientes, se mostró reactiva en la inmunodifusión en gel de agar (IDGA) en 11 y en la fijación del complemento (FC) en 10. Conclusión: ante un cuadro clínico compatible con HDP en paciente con infección por VIH que presenta fiebre, pérdida del estado general, crecimiento ganglionar, compromiso medular y piel y mucosas, el laboratorio permitirá confirmar fácilmente el diagnóstico de la sospecha clínica de la entidad (Acta Med Colomb 2011; 36: 63-67).

Objective: to identify the clinical manifestations and laboratory methods leading to the diagnosis of progressive disseminated histoplasmosis (PDH) in a cohort of patients co-infected with HIV. Design: retrospective analysis of case histories. No further intervention. Patients: forty patients with PDH and HIV infection from Hospital La María. January 1992 to December 2008. Measurements: demographic data, signs and symptoms, and laboratory tests leading to the diagnosis of PDH. Results: 40 patients, 34 males (85%) and 6 females (15%), with mean ages of 33.4 and 27 years, respectively. The dominant symptoms were: cough (77.5%), fever (90%), and anorexia with weight loss in 92.5% and 77.4%, respectively. Skin lesions in 55% and mucosal lesions in 50%, enlargement of lymph nodes in 62.5%, and hepatomegaly in 52.5%. Less frequent manifestations were dyspnea, splenomegaly, vomiting, diarrhea, and headache. Anemia was found in 85%, leucopenia in 52.5%, and thrombocytopenia in 30% of the patients. Mycological tests: directly positive in 21 samples: bronchoalveolar lavage (7), skin (6), lymph node (12), transbronchial biopsy (1), and mucosal lesion (1). H. capsulatum was isolated in all patients from samples of: skin (10), lymph node (18), blood (3), bone marrow (1), bronchoalveolar lavage fluid (10), and mucosa (3). Moreover, the fungus was isolated in more than one anatomical site in 7 patients. Serology carried out in 13 patients was reactive on agar gel immunodifusion test in 11 cases and on complement fixation in 10 cases. Conclusion: in the face of a clinical picture consistent with PDH in a patient with HIV who presents with fever, constitutional symptoms, enlargement of lymph nodes, and involvement of the bone marrow, skin, and mucous membranes, laboratory testing allows easy confirmation of the clinically suspected condition (Acta Med Colomb 2011; 36: 63-67).