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1.  Gossipyboma-A Case Report 
The Indian Journal of Surgery  2012;74(2):177-178.
doi:10.1007/s12262-011-0244-3
PMCID: PMC3309085  PMID: 23544001
2.  6-Bromo-4-[2-(4-fluoro­benzyl­idene)hydrazin-1-yl­idene]-1-methyl-3,4-dihydro-1H-2λ6,1-benzothia­zine-2,2-dione 
In the title compound, C16H13BrFN3O2S, the dihedral angle between the aromatic rings is 2.55 (19)° and the C=N—N=C torsion angle is 178.9 (3)°. The conformation of the thia­zine ring is an envelope, with the S atom displaced by −0.811 (3) Å from the mean plane of the other five atoms (r.m.s. deviation = 0.042 Å). In the crystal, C—H⋯O inter­actions link the mol­ecules and weak aromatic π–π stacking between the fluoro­benzene and bromo­benzene rings [centroid–centroid separation = 3.720 (2) Å and inter­planar angle = 2.6 (2)°] is also observed.
doi:10.1107/S1600536812037403
PMCID: PMC3470210  PMID: 23125654
3.  [4,4′-(Ethane-1,2-diyldinitrilo)­bis­(pent-2-en-2-olato)]copper(II) 0.25-hydrate 
In the title compound, [Cu(C12H18N2O2)]·0.25H2O, the coordination of the O,N,N′,O′-tetra­dentate ligand results in a cis-CuN2O2 square-planar geometry for the metal ion and the presence of two six-membered and one five-membered chelate rings. The complete complex mol­ecule is close to planar (r.m.s. deviation = 0.047 Å). The uncoordinated water mol­ecule (O-atom site symmetry 2) was modelled as half occupied. In the crystal, C—H⋯Ow and Ow—H⋯O (w = water) hydrogen bonds link the components into layers parallel to ab plane.
doi:10.1107/S1600536812017102
PMCID: PMC3344391  PMID: 22590153
5.  Assessment of NIR spectroscopy for nondestructive analysis of physical and chemical attributes of sulfamethazine bolus dosage forms 
AAPS PharmSciTech  2005;6(1):E91-E99.
The goal of this study was to assess the utility of near infrared (NIR) spectroscopy for the determination of content uniformity, tablet crushing strength (tablet hardness), and dissolution rate in sulfamethazine veterinary bolus dosage forms. A formulation containing sulfamethazine, corn starch, and magnesium stearate was employed. The formulations were wet granulated with a 10% (wt/vol) starch paste in a high shear granulator and dried at 60°C in a convection tray dryer. The tablets were compressed on a Stokes B2 rotary tablet press running at 30 rpm. Each sample was scanned in reflectance mode in the wavelengths of the NIR region. Principal component analysis (PCA) of the NIR tablet spectra and the neat raw materials indicated that the scores of the first 2 principal components were highly correlated with the chemical and physical attributes. Based on the PCA model, the significant wavelengths for sulfamethazine are 1514, (1660–1694), 2000, 2050, 2150, 2175, 2225, and 2275 nm; for corn starch are 1974, 2100, and 2325 nm; and for magnesium stearate are 2325 and 2375 nm. In addition, the loadings show large negative peaks around the water band regions (≈1420 and 1940 nm), indicating that the partial least squares (PLS) models could be affected by product water content. A simple linear regression model was able to predict content uniformity with a correlation coefficient of 0.986 at 1656 nm; the use of a PLS regression model, with 3 factors, had anr2 of 0.9496 and a sandard error of calibration of 0.0316. The PLS validation set had anr2 of 0.9662 and a standard error of 0.0354. PLS calibration models, based on tablet absorbance data, could successfully predict tablet crushing strength and dissolution in spite of varying active pharmaceutical ingredient (API) levels. Prediction plots based on these PLS models yielded correlation coefficients of 0.84 and 0.92 on independent validation sets for crushing strength and Q120 (percentage dissolved in 120 minutes), respectively.
doi:10.1208/pt060115
PMCID: PMC2750416  PMID: 16353969
sulfamethazine; near infrared (NIR); corn starch paste granulation; partial least squares (PLS); principal component analysis (PCA)
6.  Assuring quality and performance of sustained and controlled release parenterals: EUFEPS workshop report 
AAPS PharmSci  2004;6(1):100-111.
This is a summary report of the workshop, organized by the European Federation of Pharmaceutical Scientists in association with the American Association of Pharmaceutical Scientists, the European Agency for the Evaluation of Medicinal Products, the European Pharmacopoeia, the US Food and Drug Administration and the United States Pharmacopoeia, on “Assuring Quality and Performance of Sustained and Controlled Release Parenterals” held in Basel, Switzerland, February 2003. Experts from the pharmaceutical industry, regulatory authorities and academia participated in this workshop to review, discuss and debate formulation, processing and manufacture of sustained and controlled release parenterals, and identify critical process parameters and their control. This workshop was a follow-up workshop to a previous workshop on Assuring Quality and Performance of Sustained and Controlled Release Parenterals that was held in Washington, DC in April 2001. This report reflects the outcome of the Basel 2003 meeting and the advances in the field since the Washington, DC meeting in 2001. As necessary, the reader is referred to the report on the 2001 meeting. Areas were identified at the 2003 Basel meeting where research is needed in order to understand the performance of these drug delivery systems and to assist in the development of appropriate testing procedures. Recommendations were made for future workshops and meetings.
doi:10.1208/ps060111
PMCID: PMC2750946  PMID: 18465263
8.  Near-infrared spectral imaging for quality assurance of pharmaceutical products: Analysis of tablets to assess powder blend homogeneity 
AAPS PharmSciTech  2002;3(3):1-15.
The objective of this study was to evaluate near-infrared (NIR) spectroscopic imaging as a tool to assess a pharmaceutical quality assurance problem—blend uniformity in the final dosage product. A system based on array detector technology was used to rapidly collect high-contrast NIR images of furosemide tablets. By varying the mixing, 5 grades of experimental tablets containing the same amount of furosemide and microcrystalline cellulose were produced, ranging from well blended to unblended. For comparison, these tablets were also analyzed by traditional NIR spectroscopy, and both approaches were used to evaluate drug product homogeneity. NIR spectral imaging was capable of clearly differentiating between each grade of blending, both qualitatively and quantitatively. The spatial distribution of the components was based on the variation or contrast in pixel intensity, which is due to the NIR spectral contribution to each pixel. The chemical nature of each pixel could be identified by the localized spectrum associated with each pixel. Both univariate and partial least squares (PLS) images were evaluated. In the suboptimal blends, the regions of heterogeneity were obvious by visual inspection of the images. A quantitative measure of blending was determined by calculating the standard deviation of the distribution of pixel intensities in the PLS score images. The percent standard deviation increased progressively from 11% to 240% from well blended to unblended tablets. The NIR spectral imaging system provides a rapid approach for acquiring spatial and spectral information on pharmaceuticals. The technique has potential for a variety of applications in product quality assurance and could affect the control of manufacturing processes.
doi:10.1007/BF02830615
PMCID: PMC2784046  PMID: 12916932
NIR imaging; chemical imaging; NIR spectroscopy; blend uniformity; quality assurance
9.  Assuring quality and performance of sustained and controlled release parenterals: Workshop report 
AAPS PharmSci  2002;4(2):13-23.
This is a summary report of the American Association of Pharmaceutical Scientists, the Food and Drug Administration and the United States Pharmacopoeia cosponsored workshop on “Assuring Quality and Performance of Sustained and Controlled Release Parenterals.” Experts from the pharmaceutical industry, the regulatory authorities and academia participated in this workshop to review, discuss and debate formulation, processing and manufacture of sustained and controlled release parenterals and identify critical process parameters and their control. Areas were identified where research is needed in order to understand the performance of these drug delivery systems and to assist in the development of appropriate testing procedures. Recommendations were made for future workshops, meetings and working groups in this area.
doi:10.1208/ps040205
PMCID: PMC2751292  PMID: 12141269
10.  Evaluation of USP apparatus 3 for dissolution testing of immediate-release products 
AAPS PharmSci  2002;4(1):1-5.
We sought to evaluate whether U.S. Pharmacopeia (USP) apparatus 3 can be used as an alternative to USP apparatus 2 for dissolution testing of immediate-release (IR) dosage forms. Highly soluble drugs, metoprolol and ranitidine, and poorly soluble drugs, acyclovir and furosemide, were chosen as model drugs. The dissolution profiles of both innovator and generic IR products were determined using USP apparatus 2 at 50 rpm and apparatus 3 at 5, 15, and 25 dips per minute (dpm). The dissolution profiles from USP apparatus 3 were compared to those from USP apparatus 2 using the f2 similarity test. The dissolution profile from USP apparatus 3 generally depends on the agitation rate, with a faster agitation rate producing a faster dissolution rate. It was found that USP apparatus 3 at the extreme low end of the possible agitation range, such as 5 dpm, gave hydrodynamic conditions equivalent to USP apparatus 2 at 50 rpm. With appropriate agitation rate, USP apparatus 3 can produce similar dissolution profiles to USP apparatus 2 or distinguish dissolution characteristics for the IR products of metoprolol, ranitidine, and acyclovir. Incomplete dissolution was observed for the furosemide tablets using USP apparatus 3. Although it is primarily designed for the release testing of extended-release products, USP apparatus 3 may be used for the dissolution testing of IR products of highly soluble drugs, such as metoprolol and ranitidine, and some IR products of poorly soluble drugs, such as acyclovir. USP apparatus 3 offers the advantages of avoiding cone formation and mimicking the changes in physiochemical conditions and mechanical forces experienced by products in the gastrointestinal tract.
doi:10.1208/ps040101
PMCID: PMC2751286  PMID: 12049485
Dissolution; USP apparatus 2; USP apparatus 3; Immediate-Release; and Product
11.  Influence of drug release properties of conventional solid dosage forms on the systemic exposure of highly soluble drugs 
AAPS PharmSci  2001;3(3):86-92.
This study was designed to theoretically investigate the influence of drug release properties, characterized by the disintegration of a solid dosage form and dissolution of drug particles, on the systemic exposure of highly soluble drugs in immediate release products. An absorption model was developed by considering disintegration of a solid dosage form, dissolution of drug particles, gastrointestinal transit flow, and intestinal absorption processes. The absorption model was linked to a conventional pharmacokinetic model to evaluate the effect of disintegration and dissolution on the peak exposure (Cmax) and total exposure of area under the curve (AUC). Numerical methods were used to solve the model equations. The simulations show that the effect of disintegration of a dosage form and dissolution of drug particles depend on the permeability of a drug, with a low-permeability drug having a greater effect. To provide similar exposure to an oral solution formulation, a solid dosage form containing a low-permeability drug would need to dissolve more rapidly than a solid dosage form containing a high-permeability drug. It was shown theoretically for poorly permeable drugs that the disintegration rate constant has to be greater than 9 hour−1 (equivalent to approximately 90% in 30 minutes) to make both AUC and Cmax ratios higher than .9, ensuring the confidence interval of .80 to 1.25. The rapid in vitro release requirement of at least 85% dissolved in 30 minutes is sufficient for highly soluble and highly permeable drugs. However, for highly soluble and poorly permeable drugs, the appropriate in vitro release requirement seems to be 90% dissolved in 30 minutes.
doi:10.1208/ps030324
PMCID: PMC2751019  PMID: 11741275
Small intestinal transit; dissolution; disintegration; absorption modeling; bioequivalence

Results 1-11 (11)