Kunchu Kavitha

Evaluation of Ketorolac Tromethamine Microspheres by Chitosan/Gelatin B Complex Coacervation

Microspheres (MS) of Ketorolac Tromethamine (KT) for oral delivery were prepared by complex coacervation (method-1) and simple coacervation (method-2) methods without the use of chemical cross–linking agent (glutaraldehyde) to avoid the toxic reactions and other undesirable effects of the chemical cross-linking agents. Alternatively, ionotropic gelation was employed by using sodium-tripolyphosphate (Na-TPP) as cross linking agent. Chitosan and gelatin B were used as polymer and copolymer respectively. All the prepared microspheres were subjected to various physico-chemical studies, such as drug-polymer compatibility by Thin Layer Chromatography (TLC) and Fourier Transform Infra Red Spectroscopy (FTIR), surface morphology by Scanning Electron Microscopy (SEM), frequency distribution, encapsulation efficiency, in-vitro drug release characteristics and release kinetics. The physical state of drug in the microspheres was determined by Differential Scanning Calorimetry (DSC) and X-ray powder Diffractometry (XRD). TLC and FTIR studies indicated no drug-polymer incompatibility. All the MS showed release of drug by a fickian diffusion mechanism. DSC and XRD analysis indicated that the KT trapped in the microspheres existed in an amorphous or disordered-crystalline status in the polymer matrix. It is possible to design a controlled drug delivery system for the prolonged release of KT, improving therapy by possible reduction of time intervals between administrations.

Evaluation of Ionotropic Cross-Linked Chitosan/Gelatin B Microspheres of Tramadol Hydrochloride

Microspheres of tramadol hydrochloride (TM) for oral delivery were prepared by complex coacervation method without the use of chemical cross-linking agents such as glutaraldehyde to avoid the toxic reactions and other undesirable effects of the chemical cross-linking agents. Alternatively, ionotropic gelation was employed by using sodium-tripolyphosphate as cross-linking agent. Chitosan and gelatin B were used as polymer and copolymer, respectively. All the prepared microspheres were subjected to various physicochemical studies, such as drug–polymer compatibility by thin layer chromatography (TLC) and Fourier transform infrared (FTIR) spectroscopy, surface morphology by scanning electron microscopy, frequency distribution, drug entrapment efficiency, in vitro drug release characteristics and release kinetics. The physical state of drug in the microspheres was determined by differential scanning calorimetry (DSC) and X-ray diffractometry (XRD). TLC and FTIR studies indicated no drug–polymer incompatibility. All the microspheres showed initial burst release followed by a fickian diffusion mechanism. DSC and XRD analysis indicated that the TM trapped in the microspheres existed in an amorphous or disordered-crystalline status in the polymer matrix. From the preliminary trials, it was observed that it may be possible to formulate TM microspheres by using biodegradable natural polymers such as chitosan and gelatin B to overcome the drawbacks of TM and to increase the patient compliance.

Synthesis and pharmacological investigation of novel 4-(3-ethylphenyl)-1-substituted-4H-[1,2,4]triazolo[4,3-a] quinazolin-5-ones as a new class of H1-antihistaminic agents

Synthesis and pharmacological investigation of novel 4-(3-ethylphenyl)-1-substituted-4H-[1,2,4]triazolo[4,3-a] quinazolin-5-ones as a new class of H1-antihistaminic agents A series of novel 4-(3-ethylphenyl)-1-substituted-4H-[1,2,4] triazolo[4,3-a]quinazolin-5-ones (4a-j) were synthesized by the cyclization of 3-(3-ethylphenyl)-2-hydrazino-3H-quinazolin-4-one (3) with various one-carbon donors. The starting material, compound 3, was synthesized from 3-ethyl aniline by a new innovative route with improved yield. When tested for their in vivo H1-antihistaminic activity on conscious guinea pigs, all test compounds protected the animals from histamine induced bronchospasm significantly. Compound 4-(3-ethylphenyl)-1-methyl-4H - [1,2,4]triazolo[4,3-a]quinazolin-5-one (4b) emerged as the most active compound of the series and it is more potent (74.6 % protection) compared to the reference standard chlorpheniramine maleate (71 % protection). Compound 4b shows negligible sedation (10 %) compared to chlorpheniramine maleate (30 %). Therefore compound 4b can serve as the leading compound for further development of a new class of H1-antihistamines. Sinteza i farmakološko ispitivanje novih 4-(3-etilfenil)-1-supstituiranih 4H-[1,2,4]triazolo [4,3-a]kinazolin-5-ona kao nove klase H1-antihistaminika Ciklizacijom 3-(3-etilfenil)-2-hidrazino-3H-kinazolin-4-ona (3) s različitim donorima jednog C atoma sintetizirana je serija novih 4-(3-etilfenil)-1-supstituiranih 4H-[1,2,4]triazolo[4,3-a]kinazolin-5-ona (4a-j). Početni spoj 3 pripravljen je iz 3-etil anilina na novi, inovativni način, s poboljšanim iskorištenjem. U testovima in vivo na zamorcima, svi testirani spojevi pokazali su značajno zaštitno djelovanje protiv bronhospazma induciranog histaminom. Spoj 4-(3-etilfenil)-1-metil-4H-[1,2,4]triazolo[4,3-a]kinazolin-5-on (4b) najaktivniji je među testiranim spojevima (zaštita 74.6 %) i jači od referentnog standarda klorfeniramin maleata (zaštita 71 %). Spoj 4b pokazuje zanemarivu sedaciju (10 %) u usporedbi s klorfeniramin maleatom (30 %). Stoga spoj 4b može biti vodeći spoj za daljnji razvoj nove klase H1-antihistaminika.

Inter-satellite laser communication system

Laser communication links in space are attractive alternatives to present-day microwave links. This paper firstly makes an overview of an optical inter-satellite communication terminal. This terminal contains several modules such as transmit assembly, receive assembly, diplexers, mirrors assembly, acquisition and tracking sensor optics, etc. Out of these modules present in the terminal, we proposed the optical antenna design and development of-collimation lenses system. And also carried out partial prototyping and evaluating of sensitive acquisition tracking sensor (ATS) module featuring a receiving collimator fiber assembly. ATS system is overviewed using proposed two level system controls. The lower level controls the gimbals of the optical head of the electro-optical transceiver. The higher level is a fast closed loop that simultaneously controls the beam width and direction. Initial pointing acquisition assumes exchange of position related information between the satellites to establish the initial line of sight (LOS). After initial acquisition a cooperative extremum-seeking algorithm is used for the fast higher level closed loop control This compact and light weight terminal achieves single wavelength data transmission at 2.5 Gbps.

Hypoglycemic Effect of Andrographis Echioides on Streptozotocin Induced Experimental Rats

The present study aims to study the hypoglycemic effect of methanol extract of Andrographis echioides (MEAE) in streptozotocin (STZ)-induced diabetic Wistar rats. Hyperglycemia was induced in rats by single intraperitoneal injection of STZ (55 mg/kg bodyweight). Three days after STZ induction, the hyperglycemic rats were treated with MEAE orally at the doses of 200, 500, and 800 mg/kg body weight daily for 21 days. Glibenclamide (1 mg/kg, orally) was used as reference drug. The fasting blood glucose levels were measured on each 7th day during the 21 days of treatment. Serum biochemical parameters including lipid content were estimated. MEAE at the doses of 200, 500 and 800 mg/kg orally significantly (P < 0.01) and dose dependently reduced and normalized blood glucose levels as compared to that of STZ control group; the dose 800 mg/kg being the most potent showing complete normalization of blood glucose levels. Serum biochemical parameters including lipid profile were significantly (P < 0.01) restored toward normal levels in MEAE-treated rats as compared to STZ control animals. This study concludes that Andrographis echioides demonstrated promising hypoglycemic action in STZ-induced diabetic rats substantiating its ethno medicinal use.