Pharmacological and toxicological investigations of etodolac loaded gum katira microspheres prepared by W1/O/W2 emulsion solvent evaporation technique in rats

ABSTRACT Etodolac is a non-steroidal anti-inflammatory drug (NSAID) and approved by USFDA as a COX2 inhibitor. Although etodolac therapy provides clinical benefits, it is associated with upper gastrointestinal (GI) tract complications also. Etodolac loaded gum Katira microsphere (ELGKM) was prepared by W1/O/W2 emulsion solvent evaporation technique. The gastric irritation properties of orally administered pure etodolac, ELGKM and blank microspheres (without etodolac) were evaluated in experimental rats treated for 6 days. The stomach examination and biochemical investigation of stomach tissue of treated rats indicated that ELGKM formulation remarkably reduced ulcerogenecity as compared to pure etodolac. The anti-inflammatory activities of pure etodolac and ELGKMs were ascertained by the implantation of cotton pellets in rats for 6 days. Based on the results, ELGKMs showed significant anti-inflammatory activities (P<0.01) as compared to control group. The cotton pellets test suggested that ELGKM formulation retained more anti-inflammatory properties among the groups. The hematological changes, biochemical analysis and histopathological studies of subacute toxicity in rats revealed that ELGKM were the effective sustained release formulation in the treatment of chronic pain and inflammation. In conclusion, the physicochemical characterization, pharmacological and toxicological studies suggest that ELGKMs may represent as a potential candidate for sustained drug delivery (10-12 hours) in chronic joint pain related diseases with remarkably diminished gastrointestinal side effects.

Post marketing surveillance of sublingual buprenorphine naloxone combination tablets.

Background & Objectives : A combination of buprenorphinenaloxone (Addnok-N) tablets has been recently introduced in India as treatment for Opioid dependence. This study was undertaken to evaluate the possible adverse consequences following use of the buprenorphinenaloxone tablets through post marketing surveillance. Methods : National Drug Dependence Treatment Centre (NDDTC), AIIMS, India, monitored all patients receiving buprenorphine-naloxone combination tablets from the centre over a period of two and half years. Evaluation included subjective and objective side effect checklist, physical examination, and laboratory investigation. Results : Data was obtained from 1132 observations among 158 patients. Commonly reported medication effects, like muscle aches (44.0%), sleepiness (44.0%), relief from pain (41.3%), etc; are expected in opioid substitution treatment. Laboratory investigations were mostly normal except for liver enzyme abnormalities (52.2% of cases). Eight adverse events were reported in the study. No dangerous event or mortality was reported during the study.

Comparison of self-reported benzodiazepine use and urinalysis among consecutive treatment seekers at a tertiary care drug dependence treatment centre.

Information provided by drug dependent patients might be incomplete and/or discrepant. Benzodiazepines are frequently abused, but not necessarily reported, even by the treatment seeking population. The study aims to compare the self reported benzodiazepine use with a quick and effective urinalysis method. A total of 51 consecutive adult patients were included after an informed consent during their first visit to a tertiary care drug dependence treatment centre. The socio-demographic and clinical details were recorded on a semi-structured proforma. Patients were specifically asked for ever, current and recent benzodiazepine use and thereafter ten ml urine sample was collected to perform urinalysis with cassette test for benzodiazepines. The sample, predominantly males, had a mean age of 37.86 ±10.46 years. The common primary drugs of use were heroin (52.9%), alcohol (23.5%) and other opioids (21.6%).Drug use was uninterrupted in most of users (72.5%) and ranged from one to forty years. The recent benzodiazepine use was reported by 21.6% of all users whereas urinalysis by cassette test was positive in 50.9% of the treatment seekers. Denial among users was 69.2% and denial among negative self report was 45%. A poor level of agreement (K) was found between results of self-report and urinalysis for all the treatment seekers. Self report of benzodiazepine use is highly questionable among treatment seekers. The urinalysis with cassette test is a quick objective method which is recommended for routine screening.

Assessment of differential doses of buprenorphine for long term pharmacotherapy among opiate dependent subjects.

The aim of the present study was to evaluate, two different doses of sublingual buprenorphine (2 mg and 4 mg) among patients on maintenance treatment and to assess the relationship of steady state plasma level with craving. Twenty three male opioid dependent (ICD-10 DCR) subjects, were assigned to double blind randomized controlled trial of 2 and 4 mg/day doses of buprenorphine in an inpatient setting. They were evaluated thrice (2nd, 7th and 14th day) in 2 weeks for withdrawal symptoms (acute and protracted), sedation, euphoria, craving, side effects, global rating of well being and for measurement of plasma levels of buprenorphine. The data showed that there were no significant difference in scores of euphoria and sedation, protracted withdrawal symptoms and side effects, craving and overall well being and plasma level of buprenorphine among the subjects. However, both the groups had significant difference in score on almost all the measurements on final observation in comparison to initial observation. Both 2 mg/day and 4 mg/day dose of buprenorphine were effective in long term pharmacotherapy of opioid dependence without significant difference as compared by different measures used in the study.

Blocking of enhanced sensitivity to behavioral effects of naloxone induced by narcotic agonists in rats.

The present experiment evaluated whether prior treatment with naloxone could block the sensitization to opiate antagonist induced by single dose administration of pure agonist (morphine) or mixed agonist (buprenorphine). Food deprived male Wistar rats were trained to respond for food on a multiple-trial, fixed-interval 3 min schedule. Reinforcement was contingent upon a response within a 10-s limited hold period following a fixed-interval of 3 min. A trial consisted of three fixed interval of 3 min separated by a 10 min timeout period during which responses were not reinforced. The rate decreasing effects of the opioid antagonist naloxone was determined by cumulative dosing. Pretreatment with morphine (0.3 mg/ kg, SC) and buprenorphine (0.03 mg/kg, SC) resulted in an increase sensitivity to the rate decreasing effect of naloxone compared to saline pretreatment. Administration of naloxone (0.3 mg/kg) 10 min prior to pretreatment doses of buprenorphine (0.03 mg/kg; 1.0 mg/kg) and morphine (0.3 mg/kg) increased sensitization to naloxone. However, greater sensitization was observed at low dose of buprenorphine. The increased sensitivity was partially blocked at high dose of buprenorphine (1.0 mg/ kg) by naloxone pretreatment. These results suggest that the doses of naloxone used to block opioid induced sensitization might be different from those required in animals with normal sensitivity to opioid antagonists. Further agonist-induced sensitization to behavioral effects of opioid antagonist appears to be opioid receptor specific.