In-line and real-time process monitoring of a freeze drying process using Raman and NIR spectroscopy as complementary process analytical technology (PAT) tools.

The aim of the present study was to examine the complementary properties of Raman and near infrared (NIR) spectroscopy as PAT tools for the fast, noninvasive, nondestructive and in-line process monitoring of a freeze drying process. Therefore, Raman and NIR probes were built in the freeze dryer chamber, allowing simultaneous process monitoring. A 5% (w/v) mannitol solution was used as model for freeze drying. Raman and NIR spectra were continuously collected during freeze drying (one Raman and NIR spectrum/min) and the spectra were analyzed using principal component analysis (PCA) and multivariate curve resolution (MCR). Raman spectroscopy was able to supply information about (i) the mannitol solid state throughout the entire process, (ii) the endpoint of freezing (endpoint of mannitol crystallization), and (iii) several physical and chemical phenomena occurring during the process (onset of ice nucleation, onset of mannitol crystallization). NIR spectroscopy proved to be a more sensitive tool to monitor the critical aspects during drying: (i) endpoint of ice sublimation and (ii) monitoring the release of hydrate water during storage. Furthermore, via NIR spectroscopy some Raman observations were confirmed: start of ice nucleation, end of mannitol crystallization and solid state characteristics of the end product. When Raman and NIR monitoring were performed on the same vial, the Raman signal was saturated during the freezing step caused by reflected NIR light reaching the Raman detector. Therefore, NIR and Raman measurements were done on a different vial. Also the importance of the position of the probes (Raman probe above the vial and NIR probe at the bottom of the sidewall of the vial) in order to obtain all required critical information is outlined. Combining Raman and NIR spectroscopy for the simultaneous monitoring of freeze drying allows monitoring almost all critical freeze drying process aspects. Both techniques do not only complement each other, they also provided mutual confirmation of specific conclusions.

Raman spectroscopy as a process analytical technology (PAT) tool for the in-line monitoring and understanding of a powder blending process.

The aim of this study is to propose a strategy to implement a PAT system in the blending step of pharmaceutical production processes. It was examined whether Raman spectroscopy can be used as PAT tool for the in-line and real-time endpoint monitoring and understanding of a powder blending process. A screening design was used to identify and understand the significant effects of two process variables (blending speed and loading of the blender) and of a formulation variable (concentration of active pharmaceutical ingredient (API): diltiazem hydrochloride) upon the required blending time (response variable). Interactions between the variables were investigated as well. A Soft Independent Modelling of Class Analogy (SIMCA) model was developed to determine the homogeneity of the blends in-line and real-time using Raman spectroscopy in combination with a fiber optical immersion probe. One blending experiment was monitored using Raman and NIR spectroscopy simultaneously. This was done to verify whether two independent monitoring tools can confirm each other's endpoint conclusions. The analysis of the experimental design results showed that the measured endpoints were excessively rounded due to the large measurement intervals relative to the first blending times. This resulted in effects and critical effects which cannot be interpreted properly. To be able to study the effects properly, the ratio between the blending times and the measurement intervals should be sufficiently high. In this study, it anyway was demonstrated that Raman spectroscopy is a suitable PAT tool for the endpoint control of a powder blending process. Raman spectroscopy not only allowed in-line and real-time monitoring of the blend homogeneity, but also helped to understand the process better in combination with experimental design. Furthermore, the correctness of the Raman endpoint conclusions was demonstrated for one process by using a second independent endpoint monitoring tool (NIR spectroscopy). Hence, the use of two independent techniques for the control of one response variable not only means a mutual confirmation of both methods, but also provides a higher certainty in the determined endpoint.

A survey of obstetric an aesthesia practice in Flanders.

The use of locoregional anaesthesia in obstetrics in Flanders was assessed by a postal questionnaire sent to the directors of the anaesthesia departments of the 72 hospitals with an obstetric unit. 59 (82%) answers were returned. In the group of parturients who had a vaginal delivery a neuraxial technique was requested by 65% of the patients and consisted of epidural analgesia in 84%, and combined spinal epidural analgesia in 16%. Test doses are used in labour in 67%. To perform the block--spinal as well as epidural--the sitting position is somewhat preferred over the left lateral (55 versus 45%). For caesarean section general anaesthesia was used in only 5% of the deliveries, whereas spinal, single or as a part of a CSE technique, was preferred in 80%; the epidural technique was applied in 15%. There is no clear preference in technique for postoperative analgesia after caesarean delivery as both parenteral and epidural analgesia are used in 50% of the cases.

Driving and intrathecal morphine administration.

Since Belgian law recently set a limit to morphine concentration detectable in blood and urine while driving a vehicle, questions arose about the implications for the medical use of opiates. We determined morphine concentrations in whole blood and urine by gas chromatography-mass spectrometry in 15 patients on continuous intrathecal morphine administration. Effects on blood and urine concentration after water intake and the correlation with the intrathecal morphine daily dose were also evaluated. Our results confirm that, in all patients examined, the legally determined maximum blood morphine concentration of 20 ng/ml was never exceeded. Even patients on high intrathecal morphine dose schedules did never reach the maximum legal blood concentration. However, morphine concentration in urine reached levels which exceeded by far the legally determined maximum concentration of 300 ng/ml. Although legal actions against driving under the influence of morphine can only be taken after a positive urine and a subsequent positive blood sample, drivers on intrathecal opiates must be aware of the possibility of a positive roadside drug test.

RT-PCR using redundant primers to detect the three viruses associated with carrot motley dwarf disease.

A method was developed for detecting and distinguishing the viruses associated with carrot motley dwarf (CMD) disease, i.e. Carrot mottle umbravirus (CMoV), Carrot red leaf virus (CRLV) and the virus known as carrot red leaf virus-associated RNA (CRLVaRNA). Redundant primers were made that targeted the RNA-dependent RNA polymerase (RdRp) gene in all available sequences of umbraviruses and in a subset of polerovirus genomes, and specific and redundant primers were made to target the same gene in CRLVaRNA. By using these primers in RT-PCR reactions, cDNAs were amplified from total RNA isolated from Belgian parsley with CMD disease. The cDNAs were sequenced and an analysis of this data showed that the plants contained all three viruses. RT-PCR assays were optimized for the simultaneous detection of the three viruses in infected parsley and chervil plants and in individual viruliferous aphids. This is the first report of a natural infection of CRLVaRNA in a plant other than carrot and the first report of this virus outside the USA. The study also confirmed that the umbravirus in parsley with CMD disease is CMoV, and that this virus is distinct from carrot mottle mimic umbravirus (CMoMV), which is also associated with CMD, but apparently not in Europe.

Microsurgical reversal of female mechanical sterilization techniques.

This study presents the patient characteristics, the reason for requesting a reversal operation, the surgical technique and pregnancy rates after a microsurgical reanastomosis following a mechanical (ring or clip) method of sterilization in 55 women. A corrected intrauterine pregnancy rate of 90% was obtained. Ectopic pregnancy occurred in 7% of the patients. Human female sterilization presently has a very high probability of being reversible on the condition that a careful mechanical sterilization has been performed.

PIP: Tubal sterilization has become the most common contraceptive method in women over 30, but an estimated 1% request reversal. Ring or clip tubal occlusion can be reversed microsurgically by removing the device and reanastomosing the fallopian tubes, usually at the isthmic segment. Of 55 patients whose tubal occlusion was surgically reversed, 90% became pregnant, and 33 had at least 1 child. The average time between reversal and conception was 6 months. The most serious risk after sterilization reversal is ectopic pregnancy (7%-21%). Spontaneous abortion rates are also high, but this may be due to the age of the women rather than to adverse effects of the surgery. Ring or clip sterilization has only a slightly higher failure rate than electrocoagulation, but it has the advantage of being successfully reversible.

Pain treatment in metastatic prostatic carcinoma by radiofrequency thermolesion on the pituitary gland. Preliminary report.

Radiofrequency thermolesion on the pituitary gland is a simple and safe procedure to reduce pain in metastatic prostatic carcinoma. The method is indicated in patients with multiple and bilateral painful areas due to bone metastases, which are resistant to hormonal therapy and Estracyt. A good pain relief is achieved in over 60% of patients. Only one infectious complication has been encountered in a series of 17 patients treated this way.

Exotic snakebite, an unusual emergency. A case report and therapeutic considerations.

Envenomation by exotic poisonous snakes constitutes a rare emergency in Western Europe, but which in the future may be seen more frequently due to the increasing number of captive specimens in private collections. A case report of moderate envenomation by a viper is described. Diagnostic problems and therapeutic management are discussed for viper envenomation. The importance of differentiating between local and systemic poisoning is emphasized.

Gallamine and pancuronium inhibit pre- and postjunctional muscarine receptors in canine saphenous veins.

The influence of gallamine, pancuronium, suxamethonium and d-tubocurarine on adrenergic neurotransmission was studied in the isolated saphenous vein of the dog. Pancuronium but not the other muscle relaxants increased significantly the response to sympathetic stimulation and to exogenous norepipephrine; these increases were abolished after blockade of neuronal uptake by cocaine. Pancuronium and gallamine inhibited both the relaxation produced by lower doses of acetylcholine added during sympathetic stimulation (prejunctional effect) and the direct contractions evoked by high doses of the amine (postjunctional effect). In strips previously incubated with [3H]norepinephrine, gallamine had no effect on [3H]norepinephrine efflux in basal conditions and during sympathetic stimulation; it increased markedly the efflux evoked by sympathetic stimulation in the presence of acetylcholine confirming that gallamine inhibits the prejunctional effect of the latter on adrenergic transmission. When extrapolated to the intact organism, the present experiments indicate that gallamine and pancuronium augment the release of norepinephrine in vascular tissue under vagal control, which explains in part the cardiovascular effects of these muscle relaxants.

Influence of gallamine, pancuronium, d-tubocurarine and succinylcholine on adrenergic neurotransmission.

The influence of gallamine, pancuronium, d-tubocurarine and succinylcholine on adrenergic neurotransmission was studied in the isolated saphenous vein of the dog. Pancuronium increased the response of vascular smooth muscle to adrenergic nerve stimulation and to exogenous norepinephrine; gallamine, d-tubocurarine and succinylcholine had no effect. The relaxation caused by small doses of acetylcholine added during sympathetic nerve stimulation (prejunctional effect), was inhibited by pancuronium and by gallamine. In vein strips, charged with (3H) norepinephrine, acetylcholine inhibits the catecholamine-efflux evoked by sympathetic nerve stimulation. That inhibition was abolished by gallamine. This confirms that gallamine inhibits the prejunctional effect of acetylcholine on adrenergic neurotransmission. When extrapolated to the intact organism, this means that gallamine and pancuronium will augment the release of norepinephrine by acting as muscarinic antagonists also at prejunctional receptor sites in tissues exposed to combined sympathetic and vagal nerve activity. This mechanism would explain in part the cardiovascular effects of these muscle relaxants.

Clinical use of etomidate, influence on blood pressure and heart rate. Comparison with thiopentone and methohexital.

This study deals with blood pressure and heart rate measurements during the use of etomidate after premedication; the injection of etomidate is always preceded by 0.10 mg of fentanyl. Etomidate is compared with thiopentone and methohexitone. There appears to be no gross difference between the drugs as far as the blood pressure is concerned: it is decreased by 15-20%. The influence on the heart rate is typical for each drug: whereas thiopentone causes a rise of 23%, and methohexitone of nearly 40%, the rate remains constant in the etomidate series.