Process engineering and pharmaceutical manufacturing technologies

In recent years, the pharmaceutical industry is going through a period of exceptional changes, where emerging market expansion and technology advances have increased sector growth. Many new drug candidates found in the drug discovery pipeline generally have poor physicochemical and biopharmaceutical properties, such as poor solubility or low chemical compatibility, which severely limits their oral bioavailability and thus therapeutic performance. The reduction in the numbers of new molecules coming to market along with the expiry of the existing patents is also forcing the pharmaceutical industry to invest in and embrace new technologies that can save both costs and time for manufacture. One timely solution to the growing need can be the exploitation of continuous manufacturing and process engineering with better controls and reproducibility and low labour and production cost. Recently, implementation of process analytical tools (PAT) under the Quality by Design (QbD) paradigm has attracted a strong interest by pharmaceutical scientists as well as the regulatory agencies across the globe. The ultimate aims of these QbD approaches are being the science-based design and development of formulation and manufacturing processes for the predefined product quality objects

Strip casting with fluxing agent applied to casting roll

A strip caster (10) for producing a continuous strip (24) includes a tundish (12) for containing a melt (14), a pair of horizontally disposed water cooled casting rolls (22) and devices (29) for electrostatically coating the outer peripheral chill surfaces (44) of the casting rolls with a powder flux material (56). The casting rolls are juxtaposed relative to one another for forming a pouting basin (18) for receiving the melt through a teeming tube (16) thereby establishing a meniscus (20) between the rolls for forming the strip. The melt is protected from the outside air by a non-oxidizing gas passed through a supply line (28) to a sealing chamber (26). A preferred flux is boron oxide having a melting point of about 550° C. The flux coating enhances wetting of the steel melt to the casting roll and dissolves any metal oxide formed on the roll

Segmented Roll for Casting Metal Strip

Casting molten metal using a segmented roll for casting continuous metal strip. A strip caster (10) for producing a continuous strip (18) includes a tundish for containing a melt and a pair of horizontally disposed water cooled composite casting rolls (84). The casting rolls are juxtaposed relative to one another for forming a pouring basin (16) for receiving molten metal. The composite rolls are formed from a plurality of annular segments (45). Each segment preferably includes at least a pair of coolant openings (34) and means for aligning the coolant openings, such as a pair of alignment openings (26). The segments are axially aligned and structurally connected by a pair of connecting rods (42) extending completely across the width of the roll through the alignment openings and through appropriate end plates (96). Each roll includes a load supporting spindle (86) with each end of the roll sealed by a rotary seal (88). Coolant water is supplied to the composite casting roll by a flexible conduit (90) and heated water is removed through a flexible conduit (92)

Optimization of Residual Stresses in MMC's Using Compensating/Compliant Interfacial Layers. Part 2: OPTCOMP User's Guide

A user's guide for the computer program OPTCOMP is presented in this report. This program provides a capability to optimize the fabrication or service-induced residual stresses in uni-directional metal matrix composites subjected to combined thermo-mechanical axisymmetric loading using compensating or compliant layers at the fiber/matrix interface. The user specifies the architecture and the initial material parameters of the interfacial region, which can be either elastic or elastoplastic, and defines the design variables, together with the objective function, the associated constraints and the loading history through a user-friendly data input interface. The optimization procedure is based on an efficient solution methodology for the elastoplastic response of an arbitrarily layered multiple concentric cylinder model that is coupled to the commercial optimization package DOT. The solution methodology for the arbitrarily layered cylinder is based on the local-global stiffness matrix formulation and Mendelson's iterative technique of successive elastic solutions developed for elastoplastic boundary-value problems. The optimization algorithm employed in DOT is based on the method of feasible directions

Stabilized HME composition with small drug particles

A hot-melt extruded composition having finely divided drug-containing particles dispersed within a polymeric and/or lipophyllic carrier matrix is provided. The carrier softens or melts during hot-melt extrusion but it does not dissolve the drug-containing particles during extrusion. As a result, a majority or at least 90% wt. of the drug-containing particles in the extrudate are deaggregated during extrusion into essentially primary crystalline and/or amorphous particles. PEO is a suitable carrier material for drugs insoluble in the solid state in this carrier. Various functional excipients can be included in the carrier system to stabilize the particle size and physical state of the drug substance in either a crystalline and/or amorphous state. The carrier system is comprised of at least one thermal binder, and may also contain various functional excipients, such as: super-disintegrants, antioxidants, surfactants, wetting agents, stabilizing agents, retardants, or similar functional excipients. A hydrophilic polymer, such as hydroxypropyl methylcellulose (HPMC E15), polyvinyl alcohol (PVA), or poloxamer, and/or a surfactant, such as sodium lauryl sulfate (SLS), can be included in the composition. A process for preparing the extrudate is conducted at a temperature approximating or above the softening or melting temperature of the matrix and below the point of solubilization of drug-containing particles in the carrier system, and below the recrystallization point in the case of amorphous fine drug particles.Board of Regents, University of Texas Syste

Exposure of human renal proximal tubular cells to glucose leads to accumulation of type IV collagen and fibronectin by decreased degradation

Exposure of human renal proximal tubular cells to glucose leads to accumutation of type IV collagen and fibronectin by decreased degradation. Thickening and reduplication of the tubular basement membrane has been reported as an early event in diabetic nephropathy. In the current study we examined the effects of elevated D-glucose concentrations on human proximal tubular (HPTC) type IV collagen and fibronectin turnover. Incubation of confluent growth arrested HPTC with 25mM D-glucose led to accumulation of both type IV collagen and fibronectin. This effect was maximal at 48 hours and represented a sevenfold increase for fibronectin (N = 4, P = 0.04), and a threefold increase for type IV collagen (N = 3, P = 0.03) over cells exposed to 5mM D-glucose controls. This increase was not dependent on new gene transcription for either protein. Tissue inhibitor of metalloproteinases (TIMP 1 + TIMP 2) were induced following addition of 25mM D-glucose, but not when cells were exposed to 5mM D-glucose. Twenty-four hours after the addition of 25mM D-glucose there was an eightfold increase in TIMP 1 (P = 0.009, N = 4), and a tenfold increase in TIMP 2 levels (P = 0.003, N = 4), over the control values for both inhibitors. The increase in both TIMP 1 and TIMP 2 in response to 25mM D-glucose was abrogated in a dose dependent manner by the aldose reductase inhibitor sorbinil. Gelatin-substrate gel zymography showed increased activity of gelatinase A, but not of gelatinase B in response to the addition of 25mM D-glucose to HPTC. The induction of gelatinase A was accompanied by increased gelatinase A mRNA expression, which was inhibited both by protein kinase C (PKC) depletion using PMA pre-treatment, and by the addition of a PKC inhibitor. These data demonstrate that the glucose-induced accumulation of type IV collagen and fibronectin is unrelated to increased gene transcription, but may involve alterations in the degradative pathway of these basement membrane constituents. Furthermore, the data demonstrate that glucose may simultaneously activate two intracellular pathways (the polyol pathway and a PKC dependent activation pathway), which are involved in mediating separate, complementary effects on cell function