Formulation and characterization of a novel pH-triggered in-situ gelling ocular system containing Gatifloxacin.

The present research work deals with the formulation and evaluation of in-situ gelling system based on sol-to-gel transition for ophthalmic delivery of an antibacterial agent gatifloxacin, to overcome the problems of poor bioavaila-bility and therapeutic response exhibited by conventional formulations based a sol-to-gel transition in the cul-de-sac upon instillation. Carbopol 940 was used as the gelling agent in combination with HPMC and HPMC K15M which acted as a viscosity enhancing agent. The prepared formulations were evaluated for pH, clarity, drug content, gelling capacity, bioadhesive strength and in-vitro drug release. In-vitro drug release data of optimized formulation (F12) was treated according to Zero, First, Korsmeyer Peppas and Higuchi kinetics to access the mechanism of drug release. The clarity, pH, viscosity and drug content of the developed formulations were found in range 6.0-6.8, 10-570cps, 82-98% respectively. The gel provided sustained drug release over an 8 hour period. The developed formulation can be used as an in-situ gelling vehicle to enhance ocular bioavailability and the reduction in the frequency of instillation thereby resulting in better patient compliance.

Formulation and characterization of a novel pH-triggered in-situ gelling ocular system containing Gatifloxacin.

The present research work deals with the formulation and evaluation of in-situ gelling system based on sol-to-gel transition for ophthalmic delivery of an antibacterial agent gatifloxacin, to overcome the problems of poor bioavaila-bility and therapeutic response exhibited by conventional formulations based a sol-to-gel transition in the cul-de-sac upon instillation. Carbopol 940 was used as the gelling agent in combination with HPMC and HPMC K15M which acted as a viscosity enhancing agent. The prepared formulations were evaluated for pH, clarity, drug content, gelling capacity, bioadhesive strength and in-vitro drug release. In-vitro drug release data of optimized formulation (F12) was treated according to Zero, First, Korsmeyer Peppas and Higuchi kinetics to access the mechanism of drug release. The clarity, pH, viscosity and drug content of the developed formulations were found in range 6.0-6.8, 10-570cps, 82-98% respectively. The gel provided sustained drug release over an 8 hour period. The developed formulation can be used as an in-situ gelling vehicle to enhance ocular bioavailability and the reduction in the frequency of instillation thereby resulting in better patient compliance.

Aceclofenac delivery by microencapsulation using LBL self-assembly for delayed release

Colonic targeting has gained increasing interest over the past years, not just for the transport of drugs for the treatment of local diseases associated with the colon but also for its potential for transporting peptides and proteins, particularly low molecular weight peptide drugs. Without protection, such peptide drugs are usually digested within the gastric and small intestinal sections. In the present work Layer-By-Layer [LBL] self-assembly was utilized to make Aceclofenac single bilayer microcapsules produced by sequential adsorption of positively charged chitosan and negatively charged Pectin on the external surface of negatively charged Aceclofenac microcrystals. Taguchi approach was applied to determine the best concurrence of composition factors that is concentration of chitosan, pectin, centrifugation speed and incubation time. The microcapsules were characterized for encapsulation efficiency, particle size, zeta potential, scanning electron microscopy and in-vitro release kinetics. Surface electric potential of Aceclofenac microcrystals was found to be negative with zeta potential -1.39 mV, in acetate buffer of pH 4. The primary and the secondary deposit layer of chitosan and pectin was found to have a positive and negative charge with zeta potential of +5.57 mV and -22.8 mV respectively. The sequential changing of surface zeta potential after each deposition is a satisfactory indication of the LBL self-assembly of the oppositely charged polyelectrolytes. The average size and encapsulation efficiency of the optimized single bilayer microcapsules [F5] was found to be 20microm and 63.83%, respectively. The ex-vivo percentage cumulative drug release of [F5] in Phosphate buffer pH 6.8 containing 2-4% w/v colonic fecal matter of male albino rat was found to be 98.40%. The optimized batch of microcapsules showed first order release kinetics [R[2]= 0.950] in presence of colonic fecal matter

Development of meloxicam formulations utilizing ternary complexation for solubility enhancement

Meloxicam [an oxicam derivative], a relatively new cyclo-oxygenase inhibitor, is a member of enolic acid group of non-steroidal anti-inflammatory drugs. It is generally used in the treatment of rheumatoid arthritis, osteoarthritis and other joint pains. Meloxicam is practically insoluble in water [8 microg/ml], which directly influences the C[max], T[max], as well as the bioavailability of the drug. In the present study, an attempt has been made to improve the dissolution of Meloxicam by preparation of its solid dispersion using p-cyclodextrin blended with various water soluble polymer carriers i.e., HPMC [methocel IH], methylcellulose [400cps], PVP K30, HPMC [K[4]M], HPMC [50cps]. It is reported that when small amount of water soluble polymer is added to beta-cyclodextrin, its nature of solubilization significantly increases due to increase in the apparent complex stability constant. Phase solubility studies were carried out to evaluate the solubilizing power of beta-cyclodextrin along with various water soluble polymers. The solid dispersion was prepared and formulated into tablets and suspension, which were evaluated on the basis of various official tests. All the studies suggest that formulations of Meloxicam utilizing solid dispersion technique significantly enhances solubility [90 microg/ml] of the drug and results in superior formulations of the drug by using beta-cyclodextrin blended with 0.12% w/w HPMC [Methocel IH]. Ternary complexation is a valuable tool for solubility enhancement of drugs