Carvedilol is a non-selective beta-blocker indicated in the treatment of mild to moderate congestive heart failure. It is a basic, lipophilic compound. Being categorized as Class II compound as per the BCS classification system, it possesses very poor oral bioavailability and shows significant first pass metabolism (1). Thus, a strategy to improve bioavailability should aim at improving its aqueous solubility and overcoming first pass The purpose of this study was to improve the solubility and dissolution rate of carvedilol by forming a ternary complex with b-cyclodextrin and citric acid and to formulate its mouth-dissolving tablets. The rationale for preparing mouth-dissolving tablet of carvedilol was to make the drug available in a soluble form in the mouth, which would facilitate its absorption from the buccal cavity. This would help to overcome its first-pass metabolism and thereby improve bioavailability. Phase solubility studies revealed the ability of b-cyclodextrin and citric acid to complex with carvedilol and significantly increase its solubility. Ternary complexation of carvedilol was carried out with b-cyclodextrin and citric acid by physical mixing, kneading and spray drying methods and the prepared complexes were characterized by Fourier transform infra red spectroscopy, differential scanning calorimetry, powder X-ray diffractometry, scanning electron microscopy and complexation efficiency. The complex obtained by the spray drying method resulted in highest complexation efficiency and a 110-fold increase in the solubility of carvedilol. The mouth-dissolving tablets formulated using the spray dried complex with suitable excipients showed 100 % dissolution within five minutes. Accelerated stability studies of mouth-dissolving tablets carried out as per ICH guidelines revealed that the tablets were stable.

Background: Anti-inflammatory agents are widely used to relieve inflammation caused by various factors. Aim: This study was initiated with the intention to deliver low aqueous soluble ketoprofen to enhance its solubility by developing microemulsion system as a template and then incorporating it into gel phase. Materials and methods: Initially ketoprofen was solubilized into microemulsion preparation made up of clove oil, Tween 20 and propylene glycol as oil phase, surfactant and co-surfactant respectively, then it was incorporated into different concentration of gelling phase using gelling agents namely Carbopol 940, Carbopol 934 and hydroxypropyl methyl cellulose K 4 M (HPMC K 4 M). Formulated emulgels were evaluated for their physical appearance, pH, rheological properties, globule size, extrudability, drug content, spreadability, bioadhesion strength, in vitro and ex vivo drug release, skin irritation test and anti-inflammatory activity. Results: Microemulsion had shown globule size 396 nm, pH 6-6.7, viscosity 29.4 cps and zeta potential À12 mV indicating good stability. Formulated emulgels showed good physical appearance, skin acceptable pH 6-6.9, non-Newtonian shear thinning system, drug content 99.28 AE 0.16%, bioadhesion strength 48.4 gram force, globule size 473 nm, spreadability 22.96 gm.cm/s, good extrudability, in vitro release, ex vivo release did not showed any irritation reaction and possess a good anti-inflammatory activity. Conclusions: Selected batch showed enhanced drug release (92.42 AE 4.66%) as compared to marketed gel (65.94 AE 3.30). Similarly ex vivo release of formulation showed 72.22% release through mice skin compared with marketed gel. Formulations followed Korsmeyer-Peppas diffusion kinetic model. It was observed from the results that the formulated emulgel can provide promising delivery of ketoprofen.

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T he delivery of drugs to the colon through oral route is valuable in treating diseases of the colon with the expectation to protect the drug during the transit time in the gastrointestinal tract and to allow its release only in the colon. The objective of this study was to develop colon targeted drug delivery system for satranidazole that is used in the treatment of amoebiasis. Matrix tablets containing a combination of guar gum and hydroxypropyl methyl cellulose (HPMC) K4M in different ratios were prepared by wet granulation technique followed by enteric coating with Eudragit S100. Citric acid was also added, which might further facilitate drug dissolution and absorption. All formulations were evaluated for hardness, swelling, drug content and in-vitro drug release studies. The results of the studies showed that colon targeted matrix tablet of satranidazole containing guar gum and HPMC K4M in the ratio proportion of 3:1 does not released drug in 0.1N HCl (pH 1.2) and small intestine (phosphate buffer, pH 7.4). When the dissolution study was continued in colonic fluids (phosphate buffer, pH 6.8), the matrix tablets released 79.21% drug while in the presence of 4% rat cecal content, it was 94.08% at the end of the 24 h. It was expected that guar gum could be degraded by colonic microflora containing anaerobic microorganism and the release may be controlled by HPMC K4M and citric acid. Studies demonstrated that orally administered Satranidazole matrix tablets can be used effectively for the delivery of the drug to the colon. How to cite this article: Jagtap J, Patil M, Patil V. Development and in-vitro evaluation of colon specific satranidazole tablet for the treatment of amoebiasis. Asian J Pharm 2013;7:55-60.

Introduction: Etodolac is used in the treatment of acute pain and inflammation. It has low solubility because of high hydrophobicity and it is reported that upon oral administration shows gastric disturbances. This encourages the development of topical vesicular formulation. Method: In this work we used coacervation-phase separation method for the development of etodolac loaded vesicular system by using non-ionic surfactants, cholesterol and soya lecithin. Central composite design (rotatble) was used to optimize the concentrations of soy lecithin, surfactant and cholesterol. The prepared formulations were characterized by number of vesicles formed, vesicle size, zeta potential, entrapment efficiency, in-vitro permeation, ex-vivo permeation and anti-inflammatory study. Results: Etodolac was successfully entrapped in all formulations having efficiency in the range of 74.36% to 90.85%, which was more at 4 °C than room temperature. When hydrated with water; niosome in the range of 54 to 141 (per cubic mm) were spontaneously produced. The results of in-vitro diffusion study revealed that etodolac was released in the range of 71.86 to 97.16% over a period of 24 hrs. The average vesicle size of optimized formulation was found 211.9 nm with PDI of 0.5. The observed responses i.e. % encapsulation efficiency and drug release were 74.12 and 95.08 respectively. The zeta potential was -19.4mV revealed the stability of formulation which was further confirmed by no changes in drug content and drug release after stability studies. The % inhibition in paw volume was 40.52% and 43.61% for test and marketed proniosomal gel. Conclusion: Proniosomal gel formulation was stable and could enhance skin delivery of etodolac because of excellent permeation capability of vesicular system.