Rahul

There has been an extensive effort all over the world to develop inorganic complexes which can withstand severe conditions of temperature, oxidation and hydrolysis. While there has been no breakthrough, considerable progress has been made in this direction. Many of these complexes show thermal stability much higher than that of the organic substrate, employed as ligands in the synthesis of metal complexes. These complexes offer academic interest and at the same time provide materials of desired and superior qualities which promise a variety of applications. The Schiff base complexes have been synthesized from 1-(5-chloro-2-hydroxyphenyl) ethanone with 1, 3-diaminopropane using Mn(II), Co(II), Cr(II), Ni(II), Cu(II), Zn(II) and Cd(II) ions and characterized by elemental, spectral and thermogravimetric analysis. The ligand acts as tetradentade molecule coordinating through deprotonated phenolic oxygen atoms and azomethine nitrogen atoms. The isolated products are colored solids and are soluble in DMF and DMSO. The thermogravimetric study indicates all the complexes are stable up to 60-700 C. All the complexes show half decomposition temperature (Table-3) and various kinetic and thermodynamics parameters have been evaluated from thermal data. The similarity in the values of kinetic parameters indicates a common decomposition reaction mode in all the complexes. The thermal activation energy of all the complexes has been calculated by Freeman-Carroll and Sharp-Wentworth methods.

The aim of this study was to investigate the performance and release behavior of drug from hydroxypropyl methylcellulose (HPMC) matrix tablets prepared using HPMC from three different manufacturers. Three various brands of HPMC used were Methocel, Novocoat, and Zhongbao. A protocol was followed to evaluate these three HPMC samples their physico-mechanical properties such as appearance, particle size distribution, bulk density, tapped density, angle of repose, compressibility index (CI), Hausner’s ratio, swelling and morphology. Formulations were prepared using Carbamazepine (CAR) as a drug molecule, by varying drug loading and polymer concentration to evaluate the physical and comparative performance characteristics. Various drug release kinetic models were evaluated for the best fit of the formulations in order to understand the underlying release mechanisms from the formulations. The best performance with respect to release kinetics was exhibited by Methocel,while Novocoat and Zhongbao were found to have similar performance.

For evaluation of the antiemetic effects of the drugs animal models (Ferret,cat dog etc) are used. Although good guidelines may be established through the animal experiments, they may not give accurate indication of the antiemetic effect of the antiemetic drugs in patients due to species differences in pharmacokinetic and pharmacodynamic responses. Therefore, Ipecacuanha-induced emesis and flare models are used to predict more accurately the antiemetic effect of the antiemetic drugs. In ipecacuanha-induced emesis model in 10 healthy human volunteers slow intravenous injection of ondanserton -2 ml. (4 mg) was given over 5 minutes.Thirty minutes after inj. ondanserton, 30 ml. oral syrup of tincture ipecac was given with glassful of water. Then the parameters like time, number and duration of emesis were noted over 6 hour’s period. In flare model in 6 healthy human volunteers Injection Serotonin 0.05 ml of 12.98 µM was given intradermally on the flexor aspect of forearm. Resulting flare response was measured over 5 minutes. At the end of half an hour, injection ondansetron and same dose of injection serotonin was given intradermally. Resulting flare response was measured in the similar way. Out of these two models, ipecac model is technically easy and clinically relevant but its tolerability is less. Flare model has excellent tolerability but it is technically not very easy. Thus one can choose the effective model accordingly. Key words: Antiemetic, Ipecacuanha, Ondansetron, Serotonin

  Microsponge can be effectively incorporated into topical drug delivery system for retention of dosage form on skin, and also use for oral delivery of drugs using bioerodible polymers, especially for colon specific delivery and controlled release drug delivery system thus improving patient compliance by providing site specific drug delivery system and prolonging dosage intervals. Microsponge drug delivery systems offers entrapment of ingredients and is believed to contribute towards reduced side effects, improved stability, reduces systemic exposure and minimize local cutaneous reactions, increased elegance, and enhanced formulation flexibility. Topical preparations have some disadvantages like unpleasant odour, greasiness and skin irritation and fail to reach the systemic circulation this problem is overcome by microsponge delivery system. Microsponge formulations are stable over range of PH 1 to 11; Microsponge formulations are stable at the temperature up to 1300C; compatible with most vehicles and ingredients.  The present review introduces Microsponge technology along with its synthesis, characterization, programmable parameters and release mechanism of MDS.

Conventional drug therapy requires periodic doses of therapeutic agents. These agents are formulated to produce maximum stability, activity and bioavailability.  Floating drug delivery systems (FDDS) have a bulk density less than gastric fluids and so remain buoyant in the stomach without affecting gastric emptying rate for a prolonged period of time. While the system is floating on the gastric contents drug is released slowly at the desired rate from the system. The present study mainly focuses on the development and evaluation effervescent based floating matrix tablet of famotidine. This oral drug delivery offers several advantages over the standard conventional oral dosage forms. Effervescent based floating matrix tablet of famotidine was prepared using sodium bicarbonate as effervescent agent and by incorporating hydrophobic agent stearic acid which retards the drug release and allow the dosage form to float on gastric fluid for several hrs. Then the tablet was evaluated for hardness, friability, drug content and in vitro drug release. On the basis of the preliminary trials, a 32 full factorial design was employed to study the effect of independent variables, HPMC K4M: Carbopol 934P ratio (X1) and concentration of effervescent agent (X2) on dependent variables like floating lag time, Q4 and Q8. The best batch (F3) exhibited optimum floating lag time (16 sec), drug content (98.94%), Q4 (54.36 %), Q8 (93.98%) and similarity factor (83.92). The controlled release of famotidine was observed and good fit to the zero order was demonstrated.

  To study antidepressant action of nicotine in animal model of depression. The animal model for depression, used was ‘Isolation induced hyperactivity in rats’. Doses given were vehicle 1ml/kg (intra-peritoneal), imipramine10mg/kg (intra-peritoneal), nicotine0.4mg/kg (subcutaneous), nicotine 0.2mg/kg (inhalational) Nicotine administered by subcutaneous route showed significant reduction in hyperactivity at 10 and 20 minutes when compared with that of vehicle (control) group. When it was compared with imipramine, it showed significant reduction in hyperactivity at 10 minutes. Nicotine administered by inhalation route showed significant reduction in hyperactivity at 10 min and at 30, 40 50 minutes when compared with that of control group. When compared with imipramine, it showed significant reduction in hyperactivity at 10 minutes and it showed comparable effect with that of imipramine at 30, 40, and 50 minutes. Nicotine administered by inhalation route produced significant reduction in hyperactivity at 10, 20, 30, 40,50minutes, when compared with that of nicotine administered by subcutaneous route. Combination with imipramine acute or chronic administration of nicotine by inhalational route showed significant reduction in hyperactivity, when compared with imipramine treated rats. Imipramine treated rats showed significant changes in behavior with persistent sniffing, intense biting and paw licking when it compared with vehicle treated rats. Behavioral changes in nicotine treated rats showed     significant change sat persistent sniffing, intense biting, and paw licking. Effects of nicotine with imipramine were studied on all the above parameters. Nicotine administered by subcutaneous and inhalation route showed significant antidepressantactivity. Key words: Behavioral Changes, Depression, Isolation-Induced Hyperactivity, Nicotine

  Nothing in this world is stable and ever accepted. Change is the requirement of nature for the sake of adaptability. However, the pharmaceutical world is also not far off from this change. Technical advancement in pharma world also leads to the development of new dosages forms. This leads to the replacement of the older dosages forms with the newer once. But for the tablet dosages forms this replacement is substituted with modifications. On the top of it the availability of numerous evaluation parameters provides these new modifications in tablets a clear cut demonstration idea.

The term “liquisolid medication” implies oily liquid drugs and solutions or suspensions of water insoluble drugs carried in suitable non-volatile solvent systems. Liquisolid compacts demonstrated a considerably higher drug dissolution rates than those of conventionally made capsules and directly compressed tablets. This was due to the increased wetting properties and surface of drug available for dissolution. This review paper highlights the application of liquisolid technique to enhance the solubility and dissolution of water insoluble drugs. This technique is appropriate for poorly or water insoluble drugs and also for immediate or sustained release formulations. This review also depicts the various formulation parameters that must be optimized before formulation the liquisolid compacts.