Development and In Vitro - In Vivo Evaluation of Gastroretentive Drug Delivery of Nizatidine Using Natural and Semi Synthetic Polymers

Drug delivery through the numerous gastroretentive approaches has opened a new horizon for effective way of increasing patient compliance and increasing bioavailability of variety of drugs through oral rout. Many approaches with use of different polymers and other constituents can produce different range of gastroretentive systems. Especially the floating drug delivery system is the most widely used in gastroretentive dosage forms. However a lot of work is still needed to be done to overcome the different physiological and pharmaceutical barriers to develop the more effective gastroretentive dosage forms. 2. Nizatidine floating tablets were successfully prepared with hydrophilic polymers like HPMC K4M and Tamarind seed polysaccharide. 3. All formulations were evaluated for Compressibility Index, Angle of repose and Hausner ratio. The results indicated that the final blend had good flow and suited for direct compression technique. 4. From the pre-formulation studies for drug excipient compatibility it was observed that Nizatidine, doesn’t show any physical or chemical incompatibility between the drug and other excipients. 5. All formulations were tested for post compression parameters like hardness, thickness, weight variation, friability and drug content. All estimated parameters were found to be within the limits. This indicated that all the prepared formulations were good. 6. All formulations were tested for buoyancy properties like floating lag time & total floating time. Almost all the formulations showed satisfactory results. 7. All formulations were tested for in vitro drug release. The optimized formulations among HPMC K4M and Tamarind seed polysaccharide are F8. It contains combination of polymer with tamarind seed polysaccharide and HPMC K4M (1:1)ratio which exhibit least floating lag time in 50 sec and with maximum rate of drug release of 98.28% So, this formulation was considered to be the optimized formulation. 8. Comparitively kinetic model obtained for the floating tablet of nizatidine best formulation F8 and for other formulation are r2 in Zero order kinetics and mechanism is fit to Kormeyer –Peppa’s model. 9. The F8 formulation was chosen as the best formulation among all the other formulations. So stability studies are performed after one month also the formulation is stable. 10. Use of Tamarind seed polysaccharides enhanced the floating lag time, maintained the Controlled release of drugs. CONCLUSION: It can be concluded that the combination of tamarind seed polysaccharide and HPMC in ratio of (1:1) can be used to develop controlled release floating tablets of Nizatidine by incorporating sodium bicarbonate and citric acid for gas generation. However, clinical experiment on the human should be concluded with optimized formulation F8 in order to correlate in vivo performance with its in vitro behaviour

Comparison of latencies of N1 and transient evoked otoacoustic emissions: An evaluation of reverse travel in the cochlea

Transient evoked otoacoustic emissions (TEOAE) are delayed responses to short-duration frequency-specific stimuli that are measured in the ear canal after stimulus offset. This delay (latency) must stem, in part, from travel along the cochlear partition to the place of best frequency and back to the ear canal. If both the forward and reverse transmission of sound energy are along the cochlear partition, then the TEOAE latencies should be approximately twice that of an independently estimated forward travel time, obtained in this study from the N1 latency at 65 dB pe SPL. TEOAEs consisted of multiple bursts and each individual burst had approximately the same latency at all stimulus levels. Two response bursts were selected based on certain \u27identifiable features\u27, similar to those observed by Tanaka et al. (1990). The earlier of the two bursts had an approximately linear amplitude dependence on stimulus level while the later one saturated for levels above 55 pe dB SPL. The latency of the earlier burst was too short to account for travel along the cochlear partition and was, hence, taken as an indication that the first response to the stimulus occurs through the cochlear fluid. While the later burst could be detected in the ear canal signals for all individuals, the first burst was only detected for stimulus frequencies above 2 kHz and at the lower frequencies when the stimulus frequency was close to that of a click-evoked otoacoustic emission (CEOAE) for that individual. TEOAEs and N1 were also measured under aspirin administration. The elevation of N1 detection thresholds paralleled that of the behavioral thresholds. TEOAEs were measured on all three days of the aspirin schedule although the CEOAEs were eliminated within 36 hours. The occurrence of the first burst evoked with stimulus frequencies below 2 kHz reduced progressively with aspirin consumption while those evoked with a 3 kHz stimulus showed only a small elevation in detection threshold. The pattern of the response bursts for low frequency stimuli were more complicated than those observed during the pre- and post-aspirin sessions, and the earlier burst was also more vulnerable to salicylates

Some studies on elliptical microstrip stacked antenna for circular polarization

159-162Experimental investigations conducted to examine the various radiation characteristics of the elliptical microstrip stacked antenna reveal that there is a significant improvement in radiated power level, gain, beamwidth and bandwidth of the antenna when stacked with number of symmetrical parasitic elements. Stacking of antenna with four parasitic elements is found to raise the radiated power level by 4.5 dB, improve the gain by 5 dB, reduce the beamwidth from 80° to 21° and enhance the bandwidth from 0.8% to 4.0% for VSWR 1.5:1 and from 1.3% to 7.0% for VSWR 2:1 as compared to single active element

ANILINE INDUCED HISTOLOGICAL ALTERATIONS AND EVALUATION OF SERUM HORMONES IN THYROID GLAND OF MALE ALBINO RATS

Aniline is a primary aryl amine in which an amino functional group is substituted for one of the benzene hydrogen. It is a primary aryl mine and a member of anilines appears as yellowish to brownish oily liquid with a musty odour. Aniline has diverse uses in industry and in pharmaceuticals. It is used in rubber accelerators and antioxidants dyes and pigments fibres, photographic chemicals. It is also used in herbicides and fungicides. The objective of the present study is to investigate the effect of aniline on thyroid gland in albino rats. Eighteen adults albino rats were divided into three groups A, B and C. Group A was control and provided with normal food and water as well as Group B and C were received 20 mg/kg bw of aniline daily for 15 and 30 days respectively. After the completion of treatment body and organs weight and histology of thyroid gland and evaluation of serum hormones were examined. Results showed that there is decrease in body weight and increase in organ weight in experimental group as compare to control group of animals. Histopathology of thyroid gland of treated rats showed increase in number of microfollicles, reduce colloid secretion, vacuolation in colloid, breakdown of capsular layer, follicular disruption, fusion of thyroid follicles and increase interfollicular space as compared to control. Hormonal analysis of thyroid gland of treated rats showed significant decreased in thyroid hormones Tri-iodothyronine (T3), Tetra-iodothyronine (T4) level and increase Thyroid stimulating hormone (TSH) level as compared to control. From the results, It can be conclude that the aniline has potential to exerts deleterious effect on structure and function of thyroid gland

Aniline Induced Histological Alterations and Evaluation of Serum Hormones in Thyroid Gland of Male Albino Rats

Aniline is a primary aryl amine in which an amino functional group is substituted for one of the benzene hydrogen. It is a primary aryl mine and a member of anilines appears as yellowish to brownish oily liquid with a musty odour. Aniline has diverse uses in industry and in pharmaceuticals. It is used in rubber accelerators and antioxidants dyes and pigments fibres, photographic chemicals. It is also used in herbicides and fungicides. The objective of the present study is to investigate the effect of aniline on thyroid gland in albino rats. Eighteen adults albino rats were divided into three groups A, B and C. Group A was control and provided with normal food and water as well as Group B and C were received 20 mg/kg bw of aniline daily for 15 and 30 days respectively. After the completion of treatment body and organs weight and histology of thyroid gland and evaluation of serum hormones were examined. Results showed that there is decrease in body weight and increase in organ weight in experimental group as compare to control group of animals. Histopathology of thyroid gland of treated rats showed increase in number of microfollicles, reduce colloid secretion, vacuolation in colloid, breakdown of capsular layer, follicular disruption, fusion of thyroid follicles and increase interfollicular space as compared to control. Hormonal analysis of thyroid gland of treated rats showed significant decreased in thyroid hormones Tri-iodothyronine (T3), Tetra-iodothyronine (T4) level and increase Thyroid stimulating hormone (TSH) level as compared to control. From the results, It can be conclude that the aniline has potential to exerts deleterious effect on structure and function of thyroid gland