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DEVELOPMENT OF MUCOADHESIVE FILMS FOR BUCCAL ADMINISTRATION OF MONTELUKAST
Raghavendra Rao N. G *
International Journal of Pharmacy and Technology , 2010,
Abstract: The Montelukast is a leukotrine receptor antagonist (LTRA) used for the maintenance treatment of asthma, chronic asthma attacks and to relieve symptoms of seasonal allergies. Montelukast biological half life is 2.5 to 5.5 hrs there by decreasing bioavailability upto 64%. So, in order to improve the bioavailability and efficacy, we have prepared buccal films of montelukast. In the present research work, buccal films were prepared using mucoadhesive polymers like HPMC (K4M), HPMC (50cps), HPMC (5 cps), Eudragit RL-100 and PVP K-30 by Solvent Casting technique. Buccal films were characterized for number of parameters like physical appearance and surface texture, weight uniformity, thickness, folding endurance, swelling index, surface pH, drug content uniformity, in vitro residence time, bursting strength, drug–excipients interaction study, and in vitro drug release study. All the prepared films were smooth surface and elegant texture. All the prepared films are weighing in between 26.33 to 37.66 mg. The thickness of the films was in the range of 0.246 to 0.373 mm. Folding endurance was in the range of 259 to 289. Swelling index in the range of 29.81 to 43.48 %. Surface pH was in the range of 6.00 to 6.83 pH. Drug content uniformity study showed uniform dispersion of the drug throughout the formulation in the range of 94.33 to 98.33 %. The in vitro residence time for all the films is in between 3.13 to 5.50 hrs. The bursting strength of films is in the range of 6.533 to 4.366 Kg/cm2. FT-IR studies revealed that,there was no incompatibility of the drug with the excipients used. In vitro drug release studies in the range of 67.35 to 93.62 at the end of 8th hrs.
Cryptanalysis of Block Ciphers via Improved Particle Swarm Optimisation and Extended Simulated Annealing Techniques
Nalini N,G. Raghavendra Rao
International Journal of Network Security , 2008,
Abstract: Optimization heuristics have been pursued in recent years as a viable approach in cryptanalysis. Even in simple ciphers where brute force method is successful, use of these techniques demonstrates their potential application in attacks of complex ciphers. This paper establishes the applicability of a couple of optimization heuristics to cryptanalysis studies; one based on thermostatistical persistency applied to simulated annealing and the other one based on particle swarm principle. Though both methods lead to successful attacks, our improvised version of group swarm optimization yields better performance. As a vehicle of demonstration of our concept, we choose simple yet representative block ciphers such as computationally tractable versions of DES, for our studies.
FORMULATION AND DESIGN OF FAST DISSOLVING TABLETS OF FELODIPINE USING NOVEL CO-PROCESSED SUPERDISINTEGRANTS
Dr. Raghavendra Rao N. G
International Journal of Pharmaceutical Research and Development , 2010,
Abstract: In the present study, novel co-processed superdisintegrants were developed by solvent evaporation method using crospovidone and sodium starch glycolate in different ratios (1:1, 1:2 and 1:3) for use in the fast dissolving tablet formulations. The developed excipients were evaluated for angle of repose, Carr’s index and Hausner’s ratio in comparison with physical mixture of superdisintegrants. The angle of repose of the developed excipients was found to be < 300, Compressibility (%) index in the range of 15.22 to 16.88 % and Hausner’s ratio in the range of 1.15-1.27. Felodipine is used in the present study and widely accepted for its excellent antihypertensive and antianginal properties since it is calcium antagonist compound (calcium channel blocker). Fast dissolving tablets of Felodipine were prepared using the above co-processed superdisintegrants and evaluated for pre-compression and post-compression parameters. Effect of co-processed superdisintegrants (such as crospovidone, and sodium starch glycolate) on wetting time, disintegrating time, drug content, in-vitro release, and stability parameters have been studied. The prepared tablets were characterized by FTIR Studies. Based on in-vitro dispersion time (approximately 17 sec), promising formulation CP1 was tested for in-vitro drug release pattern in phosphate buffer pH 6.5 containing 0.1% SLS. Among the designed formulations, the formulation (CP1) containing 4% w/w of co-processed superdisintegrant (1:1 mixture of crospovidone and sodium starch glycolate) emerged as the overall best formulation (t 50% 1.97 min) based on drug release characteristics in phosphate buffer pH 6.5 containing 0.1% SLS. Short-term stability studies on promising formulation indicated that there were no significant changes in drug content and in- vitro dispersion time (p<0.05). From this study, it can be concluded that dissolution rate of felodipine could be enhanced by tablets containing co-processed superdisintegrant.
Research: DESIGN AND DEVELOPMENT OF FAST DISINTEGRATING TABLET BY VACUUM DRYING TECHNIQUE
N G Raghavendra Rao*,Md Subhan
Pharmacie Globale : International Journal of Comprehensive Pharmacy , 2011,
Abstract: Nimodipine is an antihypertensive, calcium channel blocker, vasodilator agent and used in the treatment of various cardiovascular disorders such as angina pectoris, cardiac arrhythmia and hypertension. Oral bioavailability of nimodipine is around 13% and having half life 9 hrs. In present research work an attempt has been made to prepare fast dissolving tablets of nimodipine by vacuum drying technique. The blend was examined for the pre-compressional parameters and post-compressional parameters. Drug compatibility with excipients was checked by FTIR and DSC studies. No chemical interaction between drug and excipients was confirmed by DSC and FTIR studies. The values of pre-compression parameters evaluated were within prescribed limits and indicated good free flowing property. All the post-compressional parameter are evaluated were prescribed limits and results were within IP acceptable limits. The results obtained showed that quantity of camphor significantly affect the response variables (P> 0.05). The formulations SBP2, SBC2, SBP3 and SBC3 shows less in vitro disintegration time 12.87, 13.48, 11.34 and 12.07 sec respectively. The in-vitro drug release showed 90 % drug released within 5 min. This data reveals that overall, the formulation SBP3 and SBC3 shows nearly faster drug release. The stability study conducted as per the ICH guidelines and the formulations were found to be stable. The results revealed that tablets prepared by the vacuum drying technique using 15 % camphor (SBP3) significantly enhanced the dissolution rate of drug. The results concluded that fast dissolving tablets of Nimodipine showing enhanced dissolution rate may lead to improved bioavailability and effective therapy by using vacuum drying technique.
FORMULATION AND EVALUATION OF ZIDOVUDINE CONTROLLED RELEASE GAS POWERED SYSTEM USING HYDROPHILLIC POLYMER
N. G. Raghavendra Rao,Shrishail M. Ghurghure
International Research Journal of Pharmacy , 2011,
Abstract: Zidovudine is the first approved compound for the treatment of AIDS; however the main limitation to therapeutic effectiveness of zidovudine is its dose-dependent toxicity, short biological half-life and poor bioavailability. The present research work an attempt has been made to develop the Zidovudine gas powered drug delivery system for controlled release. The Zidovudine gas powered tablets were prepared by direct compression method by using the different grades of hydrophilic polymer like HPMC. The sodium bicarbonates and citric acid were also used as a gas generating agent. The power blend was subjected for pre-compressional parameters. The prepared gas powered tablets are evaluated to post-compressional analysis of parameter such as hardness, friability, weight variation , thickness, drug content, lag time subsequently buoyancy time and in-vitro dissolution studies and swelling index. All the pre and post-compressional parameter are evaluated the results were within acceptable limits. The results of in-vitro buoyancy time and lag time study, the values of in-vitro buoyancy time ranges from 38 to 960 min where as floating lag time ranges from 3.5 to 60 min. The formulation F4 shows the lag time 3.5 min and buoyancy time 960 min. The results of in-vitro buoyancy time and lag time study revealed that as the concentration of sodium bicarbonate increases there is increase in total buoyancy time and decrease in lag time. It is evident from the in-vitro dissolution data that increase in citric acid concentration increased the release rate but reduced the floating time, probably due to of excess carbon dioxide, disturbing the monolithic tablet. The citric acid level in the formulations greatly influenced the drug release. The formulation, F-4 shows maximum drug release at the end of 12 hrs. Form this study, it is concluded that, the formulation retained for longer periods of time in the stomach and provides controlled release of the drug. Hence it may be increase the therapeutic efficacy of the drug by increasing the bioavailability and patient compliance.
Preparation and characterization of mucoadhesive microcapsules of salbutamol sulfate
Patil Pradnya,Raghavendra Rao N,Hiremath Doddayya
Asian Journal of Pharmaceutics , 2010,
Abstract: Salbutamol sulfate microcapsules with a coat consisting of sodium alginate and mucoadhesive polymer such as sodium carboxy methyl cellulose (NaCMC), methyl cellulose (MC), carbopol-934, and hydroxy propyl methyl cellulose (HPMC) were prepared by ionotropic gelation technique and were evaluated for morphological characters, drug content, loading efficiency, drug-polymer interactions, swelling ratio, mucoadhesive properties, and in vitro release. The resulting microcapsules were discrete, spherical, and free-flowing, and microencapsulation efficiency was 51.28-96.70%. The microcapsules prepared with alginate alone (A4) have exhibited good mucoadhesive property in the in vitro washoff test. The swelling ratio of microcapsules was enhanced with increased alginate concentration. Salbutamol sulfate release from these mucoadhesive microcapsules was slow and extended over a period of 8 h and depends upon the concentration of the alginate. The drug release from alginate-HPMC/carbopol microcapsules followed diffusion-controlled first-order kinetics. The release rate of alginate-HPMC microcapsules (A4H) was higher than other formulations and comparable with commercially available controlled-release capsules. Microcapsules with alginate alone (A4) followed diffusion mechanism. In conclusion, alginate-HPMC/carbopol mucoadhesive microcapsules could be promising vehicle for oral controlled release of salbutamol sulfate.
Development and evaluation of carbamazepine fast dissolving tablets prepared with a complex by direct compression technique
Raghavendra Rao N,Patel T,Gandhi S
Asian Journal of Pharmaceutics , 2009,
Abstract: The present study deals with the formulation of fast dissolving tablets of poorly soluble carbamazepine by the direct compression technique with β -cyclodextrin complexes using various super disintegrants like Indion-414, croscarmellose sodium, crospovidone and sodium starch glycolate. Carbamazepine is used to control different types of seizures in the treatment of epilepsy. Poor solubility in biological fluids is the major problem with this drug as also its poor bioavailability after oral administration. The rate of absorption and/or the extent of bioavailability for such a poor soluble drug is controlled by rate of dissolution in gastrointestinal fluids. Hence, to enhance the solubility of the drug, a complex of carbamazepine was prepared with β -cyclodextrin and this complex was compressed into tablets. The prepared tablets were evaluated for hardness, friability, drug content, weight variation, disintegrating time, wetting time, in vitro dissolution studies, etc. The prepared tablets were characterized by DSC, Fourier transform infrared spectroscopy (FTIR) and stability studies. The different formulations showed disintegration times between the ranges of 26.86 and 58.54 s. Drug release showed time between the ranges of 4 and 12min. Among all the formulations, B8 showed 99.89% drug release within 4min. Thus, B8 was considered as the best among the other formulations. No chemical interaction between the drug and the excipients was confirmed by DSC and FTIR studies. The stability study was conducted as per the ICH guidelines and the formulations were found to be stable, with insignificant changes in hardness, drug content and disintegration time. These results revealed that fast dissolving tablets of the poorly soluble drug, carbamazepine, showing enhanced dissolution and, hence, better patient compliance.
FORMULATION AND EVALUATION OF FAST DISSOLVING TABLETS OF CARBAMAZEPINE BY SOLID DISPERSION METHOD
N. G. Raghavendra Rao1*
International Journal of Pharmacy and Technology , 2010,
Abstract: An attempt has been made for the development of fast dissolving tablets of the carbamazepine by solid dispersion methods, using different concentrations of croscarmellose sodium as superdisintegrating agent. The major problem of this drug is very low solubility in biological fluids and poor bioavailability after oral administration. The tablets prepared were evaluated for hardness, friability,drug content, disintegrating time, wetting time and in-vitro dissolution studies. The formulations prepared with mannitol solid dispersion were showed disintegration time between the ranges of 12.83 –16.79 sec and Drug release showed between the ranges of 08 – 10 min. However the formulations prepared with PEG-6000 solid dispersion did not disintegrate in specified limit of time for fastdissolving tablet. Among all formulations SM4 showed 99.50 % drug release within 8 minutes. The prepared tablets were characterized by DSC and FTIR Studies. No chemical interaction between drug and excipient was confirmed by DSC and FTIR studies. The stability study conducted as per the ICH guidelines and the formulations were found to be stable. The results concluded that fast dissolving tablets of poorly soluble drug, carbamazepine showing enhanced dissolution, improved bioavailability,effective therapy and hence better patient compliance.
DESIGN AND DEVELOPMENT OF MUCOADHESIVE DRUG DELIVERY SYSTEM OF MONTELUKAST SODIUM
N. G. Raghavendra Rao,V. B. Suryakar
International Journal of Research in Ayurveda and Pharmacy , 2011,
Abstract: The Montelukast sodium is a leukotrine receptor antagonist used for the maintenance treatment of asthma, chronic asthma attacks and to relieve symptoms of seasonal allergies. The biological half life of montelukast sodium is 2.5 to 5.5 hrs and poor bioavailability upto 64%. Because of poor bioavailability of montelukast sodium by oral route, there is a need to increase its bioavailability by formulating it into buccal dosage forms. Hence, montelukast sodium is a suitable drug for buccal dosage forms and may provide a better therapeutic profile than oral route. In the present piece of research work, montelukast sodium buccal films were prepared using different mucoadhesive polymers like hydroxy propyl methyl cellulose (5 cps), Eudragit RL-100, poly vinyl pyrrolidone K-30, and different grades of carbopol (like carbopol-934, carbopol-940, carbopol-971 P and carbopol-974 P) by solvent casting technique. Buccal films were characterized for number of parameters like physical appearance and surface texture, weight uniformity, thickness, folding endurance, swelling index, surface pH, in vitro residence time, drug–excipients interaction study, drug content uniformity and in vitro drug release study. FT-IR studies revealed that, there was no interaction between drug and excipients used. From this study it was concluded that the film containing 5 mg of montelukast sodium were prepared by using eudragit RL 100 with hydroxy propyl methyl cellulose, hydroxy propyl methyl cellulose with carbopol 934, and hydroxy propyl methyl cellulose with carbopol 940 (F3, F4, and F5 formulations) were best formulations. Hence these formulations of montelukast sodium mucoadhesive buccal films promising one as the controlled drug delivery, shows moderate swelling, convenient resident time will lead to improve the bioavailability and greater therapeutic efficacy.
Clinical studies and antimicrobial activity of ciprofloxacin hydrochloride medicated dental gels for periodontal infection
Raghavendra Rao N,Rao K,Muthalik S,Shivanand A
Asian Journal of Pharmaceutics , 2009,
Abstract: For the effective treatment of periodontitis, ciprofloxacin hydrochloride (HCl) medicated dental gels are prepared with different hydrophilic polymers (MC, HPMC, HPC, and HEC) in different concentrations of propylene glycol. The formulations are subjected to various physicochemical studies like pH, spreadability, extrudability, viscosity, drug content, in vitro drug release, and rheological and stability studies. During the rheological studies plots of shear rate versus viscosity showed that all the gels were non-Newtonian and exhibited pseudoplastic behavior. in vitro drug release studies were carried out in the diffusion cell using a pH 7.2 phosphate buffer as a receptor medium. Formulations exhibited an extended release of the drug for over a period of 6 hours and the release depended on the type of polymer and concentrations of propylene glycol used. Stability studies showed no significant variations ( P > 0.05) in pH, spreadability, viscosity, extrudability, and drug content. An in vitro release study concluded that hydrocolloid based ciprofloxacin hydrochloride medicated dental gels appear to be probably extend the release of ciprofloxacin hydrochloride. Optimal formulations were selected for in vivo or clinical studies. The clinical evaluation of ciprofloxacin hydrochloride gels was carried out to determine the efficacy in the treatment of periodontitis. Six groups, each containing five patients, were used in the study. All the patients were evaluated for plaque index (PI) and gingival index (GI), probing depth (PD), and bleeding on probing (BOP). In all these studies, two groups were treated with formulations alone and another two groups were treated with formulations along with scaling and root planning. One group was treated with scaling and root planning only, whereas, the last group was treated as control (No treatment). All the groups showed a similar baseline PI. However, the PI values decreased remarkably in the groups treated with formulation along with scaling and root planning when compared to the other groups. Similarly, the results of GI, BOP, and PD also showed a significant reduction ( P < 0.05) in the groups treated with formulation along with scaling and root planning compared to other groups. The above studies revealed that the adjunctive use of ciprofloxacin hydrochloride gels along with scaling and root planning results in significant benefits, in the treatment of periodontitis.
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