Pulmonary drug delivery systems for tuberculosis treatment

Inhalable Antitubercular Therapy Mediated by Locust Bean Gum Microparticles

“…Real, bulk and tap densities were also very similar amongst the formulations, with real density varying within 1.3-1.4 g/cm 3 (Table 2), very common values for spray-dried powders [18,25]. Bulk densities varied between 0.14 and 0.25 g/cm 3 and tap densities had slightly increased values in comparison with the former, as a consequence of the method used for the determinations. The real density values, along with Feret's diameters, resulted in theoretical aerodynamic diameters between 0.9 and 1.8 µm (Table 1).…”

“…Real density (g/cm 3 ) was determined using a Helium Pycnometer (Micromeritics AccuPyc 1330, The preparation of unloaded LBG microparticles ( Figure 11-route A) involved grinding LBG in a glass mortar for 10 min, after which 5 mL HCl 0.1 M were slowly added and grinding continued until complete mixture of powder and HCl solution was obtained. This was followed by the addition of purified water previously heated to 85˝C, up to a final volume of 50 mL.…”

“…Conventional TB therapy involves oral co-administration of several antitubercular drugs over a period of time that may exceed two years in some cases [3]. Severe side effects are frequently reported that, in many cases, lead to therapeutic noncompliance.…”

“…Inhalable therapy allows the co-localisation of drugs and pathogens and is thought to enable increased drug concentration in the lungs, along with favoured lung-to-plasma ratio. Overall, the approach is expected to permit reducing doses and frequency of administration, possibly shortening treatment periods, resulting in general therapeutic improvement [3]. Importantly, it has been referred that inhalable TB therapy can either be used to replace oral antibiotherapy, or as add-on therapy [4].…”

“…Applying this approach requires that the inhalable antitubercular formulations exhibit suitable aerodynamic properties to reach the alveolar zone, where the alveolar macrophages hosting MTB are located [3]. Microparticles have been considered adequate for this end, ensuring not only the protection of the drugs until they reach the site of action, but also providing the necessary aerodynamic characteristics.…”