Quality of Antiretroviral Drugs Analyzed in the Drug Analysis and Research Unit During 2000-2003

During the period 2000-2003 the Drug Analysis and Research Unit received and analyzed 33 samples of antiretroviral drugs. Locally manufactured products accounted for 57.6 % of the samples, while the imported drugs constituted 42.4 %. The drugs consisted of single, double and triple component preparations. They were subjected to the identity, assay and dissolution tests. 30 samples (90.9 %) complied with compedial specifications for these tests, while 3 failed. The results obtained show that manufacture of quality generic antiretroviral drugs is achievable. Key Words: Antiretroviral, assay, dissolution, nucleoside reverse-transcriptase inhibitor East & Central African Journal of Pharmaceutical Sciences Vol.6(1) 2003: 20-2

Drug Quality Control in Kenya: Observation in the Drug Analysis and Research Unit During the Period 2001-2005

During the five-year period January 2001 to December 2005, the Drug Analysis and Research Unit received and analyzed 394 drug samples. Samples were received from regulatory authorities, local industry, non-governmental organizations, hospitals and private practitioners. The samples analyzed constituted 37.8 % locally manufactured and 62.2 % imported products. In contrast to previous years when failure rates of over 20 % were recorded, the overall rate of failure to comply with compendial quality specifications was 6.1 %, comprising of 8.7 % locally manufactured and 4.5 % imported drugs

Quality Performance of Drugs Analyzed in the Drug Analysis and Research Unit (DARU) during the Period 2006-2010

During the period 2006-2010, the Drug Analysis and Research Unit analyzed 583 samples. The samples comprised 50.6% local and 49.4% imported products. Samples were subjected to compendial or in-house specifications. The failure rate was 12.2% for local products and 14.2% for imports.  Antibacterial products recorded the highest failure rate (21.6%) while  anticancers and drugs acting on the gastrointestinal, respiratory and  reproductive systems all passed in the tests performed. The failure rate for antiprotozoals, antimalarials, antifungals, anthelminthics and analgesics was 14.3%, 12.5%, 11.8%, 8.9% and 11.5%, respectively.Key words: DARU, drug product, assay, dissolution, antimicrobial, antimalaria

Application of 57Fe Mössbauer spectroscopy as a tool for mining exploration of bornite (Cu5FeS4) copper ore

Nuclear resonance methods, including Mössbauer spectroscopy, are considered as unique techniques suitable for remote on-line mineralogical analysis. The employment of these methods provides potentially significant commercial benefits for mining industry. As applied to copper sulfide ores, Mössbauer spectroscopy method is suitable for the analysis noted. Bornite (formally Cu5FeS4) is a significant part of copper ore and identification of its properties is important for economic exploitation of commercial copper ore deposits. A series of natural bornite samples was studied by 57Fe Mössbauer spectroscopy. Two aspects were considered: reexamination of 57Fe Mössbauer properties of natural bornite samples and their stability irrespective of origin and potential use of miniaturized Mössbauer spectrometers MIMOS II for in-situ bornite identification. The results obtained show a number of potential benefits of introducing the available portative Mössbauer equipment into the mining industry for express mineralogical analysis. In addition, results of some preliminary 63,65Cu nuclear quadrupole resonance (NQR) studies of bornite are reported and their merits with Mössbauer techniques for bornite detection discussed

Improvement of composition of CdTe thin films during heat treatment in the presence of CdCl2

CdCl2 treatment is a crucial step in development of CdS/CdTe solar cells. Although this rocessing step has been used over a period of three decades, full understanding is not yet achieved. This paper reports the experimental evidence for improvement of composition of CdTe layers during CdCl2 treatment. This investigation makes use of four selected analytical techniques; Photo-electro-chemical (PEC) cell, X-ray diffraction (XRD), Raman spectroscopy and Scanning electron microscopy (SEM). CdTe layers used were electroplated using three Cd precursors; CdSO4, Cd(NO3)2 and CdCl2. Results show the improvement of stoichiometry of CdTe layers during CdCl2 treatment through chemical reaction between Cd from CdCl2 and elemental Te that usually precipitate during CdTe growth, due to its natural behaviour. XRD and SEM results show that the low-temperature (~85ºC) electroplated CdTe layers consist of ~(20-60) nm size crystallites, but after CdCl2 treatment, the layers show drastic recrystallisation with grains becoming a few microns in size. These CdCl2 treated layers are then comparable to high temperature grown CdTe layers by the size of grains

Superconductivity at 36 K in beta-Fe1.01Se with the compression of the interlayer separation under pressure

In this letter, we report that the superconductivity transition temperature in beta-Fe1.01Se increases from 8.5 to 36.7 K under applied pressure of 8.9 GPa. It then decreases at higher pressure. A dramatic change in volume is observed at the same time Tc rises, due to a collapse of the separation between the Fe2Se2 layers. A clear transition to a linear resistivity normal state is seen on cooling at all pressures. No static magnetic ordering is observed for the whole p-T phase diagram. We also report that at higher pressure (starting around 7 GPa and completed at 38 GPa), Fe1.01Se transforms to a hexagonal NiAs-type structure and displays non-magnetic, insulating behavior. The inclusion of electron correlation in band structure caculations is necessary to describe this behavior, signifying that such correlations are important in this chemical system. Our results strongly support unconventional superconductivity in beta-Fe1.01Se.Comment: 17 pages, 4 figure

Laser clad and HVOF sprayed Stellite 6 coating in chlorine rich environment with KCI at 700 °C

Laser clads and HVOF coatings from a stellite 6 alloy (Co–Cr–W–C alloy) on 304 stainless steel substrates were exposed both bare and with KCl deposits in 500 ppm HCl with 5% O2 for 250 h at 700 C. SEM/EDX and PXRD analyses with Rietveld refinement were used for assessment of the attack and for analysis of the scales. The bare samples suffered from scale spallation and the scale was mostly composed of Cr2O3, CoCr2O4 and CoO, although due to dilution haematite (Fe2O3) was detected in the scale formed on the laser clad sample. A small amount of hydrated HCl was detected in bare samples. While the corrosion of the bare surfaces was limited to comparatively shallow depths and manifested by g and M7C3 carbide formation, the presence of KCl on the surface led to severe Cr depletion from the HVOF coating (to 1 wt%). Both inward and outward diffusion of elements occurred in the HVOF coating resulting in Kirdendall voids at the coating–steel interface. The laser clad sample performed significantly better in conditions of the KCl deposit-induced corrosion. In addition to the oxides, CoCl2 was detected in the HVOF sample and K3CrO4 was detected in the laser clad sample. Thermodynamic calculations and kinetic simulations were carried out to interpret the oxidation and diffusion behaviours of coatings

Will Patients Benefit from Regionalization of Gynecologic Cancer Care?

OBJECTIVE: Patient chances for cure and palliation for a variety of malignancies may be greatly affected by the care provided by a treating hospital. We sought to determine the effect of volume and teaching status on patient outcomes for five gynecologic malignancies: endometrial, cervical, ovarian and vulvar carcinoma and uterine sarcoma. METHODS: The Florida Cancer Data System dataset was queried for all patients undergoing treatment for gynecologic cancers from 1990-2000. RESULTS: Overall, 48,981 patients with gynecologic malignancies were identified. Endometrial tumors were the most common, representing 43.2% of the entire cohort, followed by ovarian cancer (30.9%), cervical cancer (20.8%), vulvar cancer (4.6%), and uterine sarcoma (0.5%). By univariate analysis, although patients treated at high volume centers (HVC) were significantly younger, they benefited from an improved short-term (30-day and/or 90-day) survival for cervical, ovarian and endometrial cancers. Multivariate analysis (MVA), however, failed to demonstrate significant survival benefit for gynecologic cancer patients treated at teaching facilities (TF) or HVC. Significant prognostic factors at presentation by MVA were age over 65 (HR = 2.6, p<0.01), African-American race (HR = 1.36, p<0.01), and advanced stage (regional HR = 2.08, p<0.01; advanced HR = 3.82, p<0.01, respectively). Surgery and use of chemotherapy were each significantly associated with improved survival. CONCLUSION: No difference in patient survival was observed for any gynecologic malignancy based upon treating hospital teaching or volume status. Although instances of improved outcomes may occur, overall further regionalization would not appear to significantly improve patient survival

Calculating Ensemble Averaged Descriptions of Protein Rigidity without Sampling

Previous works have demonstrated that protein rigidity is related to thermodynamic stability, especially under conditions that favor formation of native structure. Mechanical network rigidity properties of a single conformation are efficiently calculated using the integer body-bar Pebble Game (PG) algorithm. However, thermodynamic properties require averaging over many samples from the ensemble of accessible conformations to accurately account for fluctuations in network topology. We have developed a mean field Virtual Pebble Game (VPG) that represents the ensemble of networks by a single effective network. That is, all possible number of distance constraints (or bars) that can form between a pair of rigid bodies is replaced by the average number. The resulting effective network is viewed as having weighted edges, where the weight of an edge quantifies its capacity to absorb degrees of freedom. The VPG is interpreted as a flow problem on this effective network, which eliminates the need to sample. Across a nonredundant dataset of 272 protein structures, we apply the VPG to proteins for the first time. Our results show numerically and visually that the rigidity characterizations of the VPG accurately reflect the ensemble averaged properties. This result positions the VPG as an efficient alternative to understand the mechanical role that chemical interactions play in maintaining protein stability