Study of neuropathic pain among patients with chronic low back pain

Chronic low back pain refers to pain, muscle tension, or stiffness localized below the costal margin and above the inferior gluteal fold [with or without leg pain] of 3 months or more in duration. Identify the neuropathic pain among patients with chronic low back pain through application of LANSS scale, identify the different aetiogenesis, study the associated medical conditions and socio-demographic features of neuropathic pain among patients with chronic low back pain. The study was carried out at Neurology department of AL Azhar University Hospitals, between Nov., 2006 and Dec., 2008. Sixty consecutive patients were included in the study. All of them suffered from chronic low back pain of 3 months or more in duration. They were subjected to the following: Complete history taking, full general and neurological examination with application of LANSS scale for detection of the neuropathic group. Routine laboratory investigation. Lumbosacral Plain x-ray anteroposterior, lateral and oblique views. Neurophysiological examination [NCS, EMG, SSEP] for the neuropathic group. Lumbosacral MRI for the neuropathic group. Ten normal controls were selected to match patient of neuropathic group in age, height and sex, they were subjected only for neurophysiologic examination [NCS and EMG]. The most prominent clinical features of neuropathic pain among patients presented mainly with neuropathic LBP where paroxysmal pain, dysesthesia, allodynia and altered pin prick threshold. The MRI has highly sensitivity for identification of disc prolapse. The needle electrode examination [NEE] has highly specificity for identification of radicuolopathy. The neuropathic pain is a contributing factor among patients presented with chronic low back pain and was attributed to many factors in our study like compressive radiculopathy, radiculopathy, nonspecific and discogenic cause. LANSS Scale is good bedside diagnostic tool that evaluate the presence of a neuropathic component of the low back pain

Formulation and evaluation of sustained release dextromethorphan resinate syrup

Aiming to decrease the dosing frequency of the antitussive dextromethorphan, different coated drug resinates were prepared and formulated in syrup form. Polystyrene divinylbenzene sulfonic acid ion exchanger [Amberlite IRP 69, H+ form] was used to prepare the resinates, which were further coated with different concentrations of carnauba wax, Eudragit RL 100, or ethyl cellulose. The in vitro release performance of the coated and uncoated resinates was determined in simulated gastric and intestinal fluids. Selected systems were formulated in syrup form and evaluated for their physicochemical and release performance when fresh and on storage. Dextromethorphan resinates showed relatively rapid release pattern, where 74.2% of the drug released through two hours in acid medium. The release pattern decreased from coated resinates on increasing polymer coat depending on the type of coating polymer. Coated dextromethorphan resinate syrups acquired mixed zero- and first-order release pattern with optimum release rates and suitable first flush values. The dextromethorphan flush in the first five minutes ranged between 9.1 and 12.3% with first-order release rate constants of 0.0048-0.0097 min-1