The graphical design space for the primary drying phase of freeze Drying: Factors affecting the dried product layer resistance.

An emerging approach to process development of a lyophilized pharmaceutical product is to construct a graphical design space for primary drying as an aid to process optimization. The purpose of this paper is to further challenge the assumption in earlier work that the maximum values of the resistance of dried product layer, Rp, is approximately constant and is independent of process conditions within the "acceptable" region of the design space. Three model formulations containing bovine serum albumin as the model protein were chosen to represent: (a) an amorphous system, (b) a crystalline system, and (c) a mixed system where both an amorphous and a crystalline component were present. Low temperature differential scanning calorimetry (DSC) and freeze dry microscopy (FDM) experiments were conducted to estimate critical product temperature. A conservative lyophilization cycle was conducted for each formulation to collect mass flow data and individual design spaces were then established. A series of lyophilization cycles were then conducted using process conditions that resided within the individual design space and the resultant product temperature and resistance of dried product layer (Rp) values were compared between the individual cycles within each formulation. The data indicated that the Rp was component dependent with the mannitol formulation exhibiting higher Rp values than the sucrose formulation. Interestingly, when mannitol was retained amorphous, the formulation exhibited a lower Rp, similar to that of the sucrose formulation. The mixed formulation exhibited intermediate Rp values. Crystallization of mannitol is hypothesized to facilitate a decrease in the size of the ice porous structure by making the water vapor flow path tortuous, thereby increasing the Rp of mannitol formulations. Within the "acceptable" zone of the individual design space, Rp was dependent on the process condition with more aggressive shelf temperature cycles resulting in lower Rp. Specific Surface Area measurements of freeze-dried solids demonstrated that more aggressive conditions resulted in smaller surface area. Freeze-dried solids of crystalline formulations consistently exhibited higher specific surface area than the amorphous formulations.

Stability of antibody drug conjugate formulations evaluated using solid-state hydrogen-deuterium exchange mass spectrometry.

Antibody drug conjugates (ADCs) have been at the forefront in cancer therapy due to their target specificity. All the FDA approved ADCs are developed in lyophilized form to minimize instability associated with the linker that connects the cytotoxic drug and the antibody during shipping and storage. We present here solid-state hydrogen-deuterium exchange with mass spectrometric analysis (ssHDX-MS) as a tool to analyze protein structure and matrix interactions for formulations of an ADC with and without commonly used excipients. We compared results of the ssHDX-MS with accelerated stability results using size-exclusion chromatography and determined that the former technique was able to successfully identify the destabilizing effects of mannitol and polysorbate 80. In comparison, Fourier-transform infrared spectroscopy results were inconclusive. The agreement between ssHDX-MS and stressed stability studies supports the potential of ssHDX-MS as a method of predicting relative stability of different formulations.

Equipment Capability Measurement of Laboratory Freeze-Dryers: a Comparison of Two Methods.

The objective of this investigation was to evaluate two methods for measuring the maximum sublimation rate that a freeze-dryer will support-the minimum controllable pressure method and the choke point method. Both methods gave equivalent results, but the minimum controllable pressure method is preferred, since it is easier, faster, and less subjective. The ratio of chamber pressure to condenser pressure corresponding to the onset of choked flow was considerably higher in this investigation (up to about 20:1) than in previously published reports. This ratio was not affected by the location of the pressure gauge on the condenser; that is, on the foreline of the vacuum pump versus on the body of the condenser itself. The total water loss due to sublimation as measured by tunable diode laser absorption spectroscopy was consistently within 5% of gravimetrically determined weight loss, regardless of whether the measurement took place during choked versus non-choked process conditions.

18F-FDG PET/CT in Lymphomatoid Papulosis Mimicking Primary Cutaneous Anaplastic Large Cell Lymphoma.

Lymphomatoid papulosis is a benign self-healing condition, presenting as papulonodular skin eruptions and mimicking malignant cutaneous lymphomas histopathologically. F-FDG PET/CT findings in this benign condition have not been described in detail in the literature. We present a case of lymphomatoid papulosis mimicking primary cutaneous anaplastic large cell lymphoma histopathologically and demonstrating intensely FDG-avid cutaneous lesions on F-FDG PET/CT, which disappear spontaneously in the follow-up scan.

Fluorescence turn on detection of bilirubin using Fe (III) modulated BSA stabilized copper nanocluster; A mechanistic perception.

Hyperbilirubinemia is the condition when bilirubin exceeds normal concentration in body (19.80 mg/mL in newborns and 1.19 × 10-2 mg/mL in adults). Bilirubin encephalopathy in newborns may cause irreversible neurological disorders. Current methods for detection of bilirubin suffer from compromising accuracy. In the present work, bovine serum albumin stabilized copper nanocluster (BSA-CuNCs) was synthesized via a one pot microwave assisted method as a turn on detector for bilirubin. The synthesized BSA-CuNCs having size less than 4 nm, exhibited bright blue emission at 405 nm. Interestingly, no observable change in fluorescence emission was noticed over a wide pH range (1-11) or at high ionic conditions. However, the interaction of Fe3+ with BSA-CuNCs induces quenching of fluorescence. Moreover, the fluorescence can be regained by the addition of bilirubin over other possible coexisting biomolecules. A good linearity was observed for BSA-CuNCs based turn on probe with a Limit of Detection (LoD) 6.62 nM. Furthermore, real sample analyses were carried out with human serum and urine which showed good recovery percentage.

The Influence of Mannitol Hemihydrate on the Secondary Drying Dynamics of a Protein Formulation: A Case Study.

The objective of this research was to study the atypical secondary drying dynamics observed during the freeze-drying of a formulation consisting of mannitol, disaccharide, and sodium chloride, where "bursts" of water vapor release were observed during secondary drying as detected by comparative pressure measurement. "Thief" samples were removed at the end of primary drying and during secondary drying as the shelf temperature was increased in a stepwise fashion. These samples were examined by X-ray powder diffraction and thermal analysis. From the X-ray powder diffraction data, we determined that mannitol crystallized predominantly as its hemihydrate. The physical state of mannitol changed from the hemihydrate form to anhydrous forms during secondary drying. Investigation of the effect of excipients on mannitol crystallization demonstrated that sodium chloride (at 225 mM, 1.3% w/v) had the greatest influence on hemihydrate crystallization, followed by trehalose and sucrose. However, only negligible hemihydrate formation was observed when mannitol was freeze-dried either by itself or in the presence of 150 mM sodium chloride and no hemihydrate in the presence of 75 mM sodium chloride. In general, a combination of a disaccharide and sodium chloride promoted the hemihydrate formation to a greater extent than the individual components. Comparative pressure measurement was demonstrated to be an effective tool to monitor mannitol hemihydrate dehydration during secondary drying.

S,N-doped carbon dots as a fluorescent probe for bilirubin.

Carbon dots doped with sulfur and nitrogen (S,N-CDs) were utilised to design a paper-stripe based fluorescent probe for the detection of bilirubin. The S,N-CDs were synthesized through a microwave assisted route by using citric acid as carbon source and L-cysteine as a source of nitrogen and sulfur. The S,N-CDs exhibit bright blue fluorescence emission with a peak at 452 nm. Fluorescence is quenched by Fe(III) but selectively restored by bilirubin. The quenched fluorescent probe exhibit significant selectivity and sensitivity for bilirubin in the 0.2 nM to 2 nM concentration range, with a 0.12 nM detection limit. The method was applied to the determination of bilirubin in spiked human serum and urine samples. The method was used to design a paper based test stripe as a point of care device for visual bilirubin detection. Graphical abstract Schematic representation of sulphur and nitrogen doped carbon dots whose fluorescence is quenched by Fe(III) and turned on by bilirubin. Photograph of the corresponding system under day light and UV shows the feasibility of the phenomenon. The applicability of the assay was further extended by impregnating the probe on a filter paper.

Hepatoprotective activity of Oxalis corniculata L. ethanolic extract against paracetamol induced hepatotoxicity in Wistar rats and its in vitro antioxidant effects.

Oxalis corniculata is well known for its medicinal properties like anti-inflammatory, digestive, diuretic, antibacterial, antiseptic etc. The present study focuses on the ability of O. corniculata to alleviate liver damage caused by over dose of paracetamol. Antioxidant activity of O. corniculata was evaluated using the free radical scavenging activity of 1, 1-diphenyl-2- picrylhydrazyl radicals, total anti oxidant capacity by phosphomolybdenum method and total phenolic content was also evaluated. The ethanolic extract of whole plant of O. corniculata (OC, 500 microg/mL, po) significantly reduced 1, 1-diphenyl-2- picrylhydrazyl radicals. This dose also caused significant reduction (62.67%) in malondialdehyde levels of murine hepatic tissues. The antioxidant capacity of OC was comparable to that of standard ascorbic acid and showed 53.5 microg of phenol/mg OC. Rats pre-treated with OC for 4 days showed significant reduction in the serum enzymes such as glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, alkaline phosphatase, serum bilirubin and showed almost normal histological liver architecture of the treated groups compared to paracetamol induced hepatic damage group, indicating its hepatoprotective and antioxidant potential.

Stereoselective synthesis of complex polycyclic aziridines: use of the Brønsted acid-catalyzed aza-Darzens reaction to prepare an orthogonally protected mitomycin C intermediate with maximal convergency.

A concise synthesis of a highly functionalized intermediate lacking only C10 of the mitomycin backbone is described. The key to this development is the Brønsted acid-catalyzed aza-Darzens reaction used to forge the cis-aziridine. Additionally an oxidative ketalization fortuitously occurs during the quinone-enamine coupling step, leading to an orthogonally protected hydroquinone.

Linear verrucous hemangioma.

Verrucous hemangioma is a rare, vascular malformation. It is usually present at birth, but there is often a gradual increase in size and number with age; occasionally it presents in later adulthood. The lesions usually present as hyperkeratotic, bluish, and partly confluent papules and plaques. Linear verrucous hemangioma is an even more rare presentation described in very few published reports. We report a 30-year-old male patient with linear verrucous hemangioma who experienced a sudden increase in the size of his verrucous hemangioma during adulthood.

Synthesis of an advanced intermediate en route to the mitomycin natural products.

[Structure: see text] An advanced intermediate in our planned synthesis of mitomycin C has been acquired in nine steps from tert-butyl glyoxylate. The aziridinyl pyrrolidine and quinone subunits are coupled regioselectively to arrive at an enamine that is prepared for C10 homologation.

Free Radical-Mediated Aryl Amination: A Practical Synthesis of (R)- and (S)-7-Azaindoline α-Amino Acid.

Two nonnatural proline derivatives, (S)- and (R)-7-azaindoline α-amino acid have been prepared and isolated as their trifluoroacetate salt on gram scale. The convergent sequence (6 steps from 2-bromopyridine) employs a combination of enantioselective phase transfer catalyzed glycine alkylation and free radical-mediated aryl amination. Implementation of the solid-liquid phase transfer conditions requires manual pulverization of cesium hydroxide, efficient mechanical stirring, and effective low temperature control. This large scale free radical cyclization protocol replaces benzene solvent with toluene without complication, and the crystalline nature of the intermediates and final product enables straightforward purification at each stage, including enantiomeric enrichment (89 to >99% ee for 4b).

Larvivorous potential of some indigenous fishes of Sherthallai region with special reference to their efficacy in control of mansonioides.

Larvivorous potential of some indigenous fishes collected from natural habitats of Sherthallai region in Kerala state, India, was studied under laboratory as well as controlled field conditions. Ophiocephalus striatus was observed to consume significantly higher number of mansonioides larvae (354/g body wt/day), followed by Macropodus cupanus (231/g body wt/day). The proportion of adult vector mosquito emergence was significantly (P less than 0.05) lower in cages with fish species studied, as compared to that of control group of cages without fishes. Natural food preference of the selected fish species was also studied indirectly through gut content analysis.

A cost benefit analysis of fish culture strategy towards the control of mansonioides in Shertallai, Kerala state.

The cost benefit analysis of fish culture as a means for vector control towards the containment of Brugian filariasis in Shertallai, a highly endemic tract for this disease in Kerala was carried out. While the financial gain accrued to the community was to the tune of Rs. 1,82,052 in ponds (under monoculture) with Chinese grass carp from 763 ponds, it was Rs. 1,83,740 from 1000 ponds under polyculture with Catla catla, Cyprinus carpio, Labeo rohita, Labeo fimbriatus, Cirrhina mrigala and Ctenopharyngodon idella (Chinese grass carp). Monoculture with Giant gourami (Osphronemous goramy) fetched an income of Rs. 7,654 to the community from 128 ponds. A marked reduction in weed reinfestation/vector breeding was observed in ponds under fish culture than other without fishes. The study clearly indicates that fish culture is an ideal strategy for Mansonioides control as it can bring perceptible benefits to the community.

Weedivorous fishes for the control of vectors of Malayan filariasis.

An attempt was made to assess the efficacy of phytophagous fishes viz., Ctenopharyngodon idella, the Chinese grass carp and Osphronemus goramy, the giant gourami in the control of mansonioides mosquitoes by checking the growth of aquatic weeds which support their breeding. When C. idella and O. goramy were used in monoculture 80.21 and 81.25 per cent of the ponds were kept free from weeds. With polyculture using grass carp in combination with other varieties of carps, only 70.10 per cent of the ponds were kept out from the reinfestation of weeds. Even in the reinfested ponds, there was significant reduction (P less than 0.05) in vector breeding in all the three types of piscicultures, as compared to the control ponds. The utility of weedivorous fishes in the elimination of aquatic weeds and thereby breeding of vectors of Malayan filariasis was thus demonstrated.