Dry powder inhalers have attracted more interest over the years in every aspect related to them. Interestingly, when focusing on the effects of particle morphology of the active or carrier (excipient), it is generally regarded particle size and shape to influence drug availability of aerosolized particles. However, to date, few studies have examined the effect of texture, i.e., roughness, on this relationship. The main objective of the present work is to gain a closer understanding of the influence of carrier morphology on the aerosolization performance of dry powder inhaler formulations. Image analysis and microscopy were used to visualize the aerosolization process. It is considered that the scale of morphological features on the surface of the carrier particles is responsible for the dispersion of the powder formulation, separation of the drug/carrier, and entrainment from a dry powder inhaler. Thus, for this study, the carrier particles of different surface roughness were mixed with micronized salbutamol sulphate.Aerosolization in vitro testing was used to evaluate the performance. The results indicate a connection between the qualitative surface roughness of coarse carriers and aerosolization performance during powder dispersibility. This investigation demonstrated that indeed, powder dispersion, a dynamic process, is influenced by the scale of the carrier morphology.

Amorphous solid dispersions (ASDs) consisting of acetaminophen (APAP) and copovidone were systematically studied to identify effects of drug loading and moisture content on mechanical properties, thermal properties, and tableting behavior. ASDs containing APAP at different levels were prepared by film casting and characterized by differential scanning calorimetry and nanoindentation. The glass transition temperature (Tg) continuously decreased with increasing amount of APAP, but the hardness of ASDs was increased at a low APAP content and reduced at high APAP content. This in turn significantly influenced tablet quality. Water reduced both the hardness and Tg of ASDs, and the APAP loading level corresponding to the transition to the softening mechanism was lower at a higher relative humidity. Overall, the mechanical properties, rather than the thermal properties, better represent the plasticization/antiplasticization effect of small molecule to ASDs.

Dry powder inhalers are often formulated by attaching micronized drug particles onto carrier particles, which are generally lactose. In this study, commercially available lactose was air jet milled to produce unique slab-like coarse carrier particles, which have larger and rougher surfaces compared to other commercially available lactose. Two key processing factors, i.e.,classifier speed and jet milling pressure, were systematically investigated. The largest fraction of slab-like particles in the resulting powder was obtained at a classifier speed of 3000 rpm.The slab-like coarse carrier particles are expected to exhibit superior performance than commercial lactose due to their unique surface properties.

The goal of this work was to evaluate the ability of Particle Image Velocimetry (PIV) to visually assess dry powder dispersion within an inhaler. Herein, the study reports particle movement characterization of entrained low-micron particles within an inhaler to further scheme of potential mechanisms. Carrier based DPI formulations were prepared and placed in a transparent model Rotahaler® chamber for the aerosolization experiments. Then using the PIV, a high-speed camera, the dried powder dispersion was directly observed and analyzed for all, neat, binary and ternary systems. Powder dispersion mechanisms proposed include drag force, impact with obstacle and particle-particle collision; these different mechanisms depended on the powder flow properties. A revised ratio of aerodynamic response time (τA) to the mean time between collisions (τC) was found to be 6.8 indicating that particle collisions were of strong influence to particle dispersion. With image analysis techniques, visualization of particle flow pattern and collision regions was possible; suggesting that the various mechanisms proposed did govern the powder dispersion.

New coprocessed excipients composed of α-lactose monohydrate (a filler), HPMC E3 (a binder), and PVPP (a superdisintegrant) were developed by spray drying in this study to improve the tableting properties of lactose. Factors affecting the properties of the coprocessed excipients were investigated by a 3×3×2 factorial design. These factors include lactose grade (90M, 200M, and 450M), percentage of HPMC (3.5%, 7.0%, and 10.5%), and percentage of PVPP (0% and 3.5%). The results show that the compactability of the excipients could be significantly improved by increasing either the percentage of HPMC or the primary particle size of lactose. The addition of 3.5% PVPP had little effect on the compactability, but significantly improved the disintegration ability. The developed coprocessed excipients have much lower yield pressures and much higher working efficiency during tableting compared to the main raw material (α-lactose monohydrate). These improvements are mainly attributed to the addition of HPMC and the proximately 30% amorphous lactose formed during process. Both HPMC and amorphous lactose were homogeneously distributed on the surface of the secondary particles, maximizing their effect. Furthermore, the low hygroscopicity and high glass transition temperature of HPMC led to a high yield. The drug loading capacity of the newly coprocessed excipients is also excellent. In summary, the tri-component coprocessed excipients investigated are promising and worthy of further development.

A dry powder inhaler (DPI) is a dosage form that consists of a powder formulation in a device which is designed to deliver an active ingredient to the respiratory tract. It has been extensively investigated over the past years and several aspects relating to device and particulate delivery mechanisms have been the focal points for debate. DPI formulations may or may not contain carrier particles but whenever a carrier is included in a commercial formulation, it is almost invariably lactose monohydrate. Many physicochemical properties of the lactose carrier particles have been reported to affect the efficiency of a DPI. A number of preparation methods have been developed which have been claimed to produce lactose carriers with characteristics which lead to improved deposition. Alongside these developments, a number of characterization methods have been developed which have been reported to be useful in the measurement of key properties of the particulate ingredients. This review describes the various physicochemical characteristics of lactose, methods of manufacturing lactose particulates and their characterization.

Objective:To quantify geniposide concentration in the granules for removing goiter and restraining excess(Xiao Ying Ping Kang)by HPLC.Methods:The quantification was conducted by HPLC consisted of a ODS column(DIAMONSIL,250 mm×4.6 mm,5μm),an mobile phase of acetoni- trile-water(5.3:94.7)with a flow rate of 0.8 mL·min~(-1)and the detection at 238 nm.Results:The lin- earity of geniposide concentration curve was in the ranges of 0.12～0.24μg(r=0.9992,n=5).The mean recovery was 96.79% with RSD of 1.1%(n=5).Conclusion:The convenient and reliable HPLC method is applied to quantify geniposide.

Osmotical controlled oral drug delivery system has its glorious prosperous.By referring to the previous articles,the author attempts throw some light on its development,with the different sections: the development,preparation,coating,percolating.

Objective:To establish a HPLC method for the determination of rhodioloside in Jingtian Jialing tablets.Methods:The HPLC separation was performed on a DIAMONSIL C18 column (250 mm×4.6 mm, 5μm)with column temperature at 30℃, a mobile phase consisted of acetontrile-0.1%H_3PO_4 (5.3∶94.7) with a flow rate of 1.0 mL·min -1 , and a UV detection at 280 nm.Results:The calibration curve was linear in the concentration range of 0.102～1.524 μg,( r = 0.999 8 ) with a RSD of 0.32%( n =5). The mean recovery rate was 99.9%.Conclusion:This simple, rapid and specific HPLC method to determine rhodioloside in Jingtian Jialing tablets is achieved.

Dry powder inhaler (DPI) is a dosage form for delivering fi ne drug powders to the respiratory tract. Particle size and size distribution, proportion of fi nes, particle shape, particle surface roughness, fl ow rate and adhesion force have been reported to affect the aerosolization process. Several mechanisms for particle dispersion in DPI have been considered; a proposed mechanism to explain the particle dispersion phenomenon is the active site theory. However, there have been several confl icting reports, therefore, an agglomeration/fracture hypothesis has been also proposed. Particle dispersion is associated with events such as impact, acceleration, shear stress, and turbulent fl ow. The aim of this study is to use high-speed video imaging to provide direct experimental observation of the particle dispersion process in order to unveil a mechanism for particle dispersion. Mixture of micronized lactose and coarse lactose carrier was placed in a model inhaler device, a high speed video imaging was used to capture the dry powder inhalation process. The fl ow pattern was found to be turbulent. Particles were observed to collide with one another, causing detachment of micronized particles from the surfaces of the coarse lactose particles. Impact of the powder agglomerates on the device grid also contributed to deaggregation and dispersion of the particles. The fi ndings suggest that collision and impact are important mechanisms for the dispersion of DPI particles.