Electrophoresis. 1998 Nov;19(16-17):2883-9.
Use of cyclodextrins in capillary electrophoresis: resolution of tramadol enantiomers.

Rudaz S, Veuthey JL, Desiderio C, Fanali S.

Istituto di Cromatografia del CNR, Area della Ricerca di Roma, Monterotondo Scalo, Italy.

Capillary zone electrophoresis was successfully applied to the enantiomeric resolution of racemic tramadol. Both uncoated and polyacrylamide-coated capillaries were tested for method optimization using either negatively charged or native cyclodextrins (CD) added to the background electrolyte (BGE). The resolution was strongly influenced by the CD type and concentration as well as by the pH and the concentration of the BGE. Among the CDs tested, carboxymethylated-beta-cyclodextrin allowed the baseline separation of tramadol enantiomers. After the method was optimized, it was validated in a coated capillary for enantiomeric analysis of tramadol enantiomers in pharmaceutical formulation, including specificity and elution order, linearity, accuracy and precision, determination of limit of detection (LOD) and quantification (LOQ), enantiomeric purity linearity, freedom from interference, and stability of sample solutions. Precision at the target concentration was less than 2%, with an accuracy higher than 99%. Furthermore, the method was able to detect 0.3% and to quantify 1% of the minor enantiomer in the presence of the major one at the target value.

Tramadol reference source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9870383&dopt=Abstract tramadol Ultram




Med Hypotheses. 1998 Aug;51(2):167-8.
Venlafaxine-tramadol similarities.

Markowitz JS, Patrick KS.

Department of Pharmacy Practice, Institute of Psychiatry, Medical University of South Carolina, Charleston 29425-0810, USA.

Venlafaxine and tramadol are relatively new compounds indicated for the treatment of depression and pain, respectively. These agents share a number of molecular and pharmacological features that may allow for broader and overlapping therapeutic indications for both drugs. Additionally, certain patient populations with coexisting depression and pain syndromes could potentially be treated with a single agent.

Tramadol reference source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9881825&dopt=Abstract tramadol Ultram

invivo.edu

NEW OPIOID ANALGESICS: Progress in pain reliet has recently been achieved with the introduction of new opioid analgesics such as tramadol and the pediatric preparation of codeine phosphate as well as powerful long-release opioids which can be administered per os, or percutaneously for transdermal fentanyl. CO-ANALGESICS: Other drugs, mainly antidepressants and anti-convulsants, can be usefully combined with analgesics. New serotonin uptake inhibitors and anticonvulsants (gabapentin and lamotrigin) have the advantage of better tolerance. None of these drugs has marketing approval in France for their pain relieving effects. The same is true for clonidine and neostigmine which, after spinal infusion, potentialize opioids and for ketamine which can relieve neuropathy pain by dissociative anesthesia. NEW ANTI-MIGRAINE DRUGS: New drugs have been developed for specific types of pain such as migraine. The new "triptans" are tolerated better than sumatriptan and is reimbursed by the national social security. REFRACTORY NEUROPATHY PAIN: Indications for electrical stimulation techniques conducted in a neurosurgery unit have been identified. Stimulators may be implanted in spinal or supra-spinal localizations. REGULATORY ASPECTS: New legislation has reorganized health care for pain relief in France. The new texts take into consideration personnel training, the health care network and progress in therapeutics.

Tramadol reference source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9893699&dopt=Abstract tramadol Ultram




Bratisl Lek Listy. 1998 Oct;99(10):531-5.
[Actions of drugs affecting the cough reflex]

[Article in Slovak]

Nosalova G.

Ustav farmakologie Jesseniovej lekarskej fakulty Univerzity Komenskeho v Martine, Slovakia.

BACKGROUND AND AIM: Authors evaluated the part of some receptor systems in the antitussive activity of drugs. METHOD: The cough was induced by mechanical stimulation of the airways. Unanesthetized cats were used in this study. RESULTS: They followed: 1. statistically highly significant decrease of cough parameters after administration the drugs influencing the different types of opiate receptors--tramadol, tilidine, pentazocine, codeine and butorphanol. Every of these drugs were administered in a dose 10 mg/kg b.w. intraperitoneally, 2. the antitussive activity of codeine was decreased by pretreatment with naloxone only in part, 3. selective antagonist 5-HT2 receptors ketanserine (1 mg/kg b.w.) decreased antitussive effect of codeine by 10% and effect of tramadol by 20%, 4. the ability of codeine to reduce the cough parameters was unchanged after pretreatment with haloperidol (0.1 mg/kg b.w.), 5. whereas the pretreatment with reserpine decreased the cough-suppressing effect of codeine, 6. the application of gabaergic agent gabalid leads to the highly significant decrease the cough parameters. Results of these experiments showed that gaba-ergic mechanism might be involved in the mechanism of action of narcotic antitussives agents, 7. we showed, that inhibition of glutaminergic synaptic transmissions afferent impulses from cough receptors with dextromethorphan leads to suppressing cough reflex in cats. CONCLUSIONS: Antitussive activity of agents is not only mediated by means of mi opiate receptors. The results suggest, that gabaergic, serotoninergic systems and activity of NMDA receptors play an important role in the mechanism of action of antitussive drugs. Decrease in levels of brain monoamines modifies the cough-depressant effect of codeine. (Fig. 7, Ref. 23.)

Tramadol reference source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9919754&dopt=Abstract tramadol Ultram




J Pharm Biomed Anal. 1998 Dec;18(4-5):777-83.
Determination of tramadol in various dosage forms by capillary isotachophoresis.

Pospisilova M, Polasek M, Jokl V.

Department of Analytical Chemistry, Faculty of Pharmacy, Charles University, Heyrovskeho, Czech Republic.

Cationic capillary isotachophoresis (ITP) with conductometric detection has been used for separating and determining milligram amounts of tramadol [2-dimethylaminomethyl-1-(3-methoxyphenyl)-cyclohexanol hydrochloride] (I) in seven commercial mass-produced pharmaceutical preparations. The optimised ITP electrolyte system consisted of 5 mM potassium picolinate + 5 mM picolinic acid (pH 5.25) as the leading electrolyte and 10 mM formic acid as the terminating electrolyte. The driving and detection currents were 50 microA (for 320 s) and 10 microA, respectively (a single analysis took 12-15 min). Under such conditions the effective mobility of I was determined as 24.26 x 10(-9) m2 V(-1) s(-1) (with tetraethylammonium ion as standard); thermodynamic pKa value of I was 9.44 +/- 0.03 (n = 8) as determined by UV spectrophotometry at 25 degrees C and I = 0.01 (NaCl). The calibration graph relating the ITP zone length to the concentration of I was rectilinear (r = 0.99997) in the range 15-180 mg l(-1) of I. The relative standard deviation (RSD) was 0.21% (n = 6) when determining 60 mg l(-1) of I in pure test solution. Sample pre-treatment of the dosage forms involved dilution or extraction of I with water (for suppositories the extraction was carried out in an ultrasonic bath at 40 degrees C for 10 min). The method was suitable for determining 50 or 100 mg ml(-1) of I in injections and drops, 50 mg of I in capsules, and 100 mg of I in suppositories with RSD values 0.4 to 1% (n = 6). According to the validation procedure based on the standard addition technique the recoveries were 97.2-100.1% of I.

Tramadol reference source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9919980&dopt=Abstract tramadol Ultram