Aceclofenac organogels: in vitro and in vivo characterization.

PURPOSE: To develop and evaluate the suitability of lecithin organogels containing aceclofenac for topical application and compare its In vitro and In vivo effects with conventionally used hydrogels. METHODS: The components and their concentration necessary for organogels formation were evaluated using phase diagram. Solubility of aceclofenac was determined. The In vitro skin permeation ability of aceclofenac from ethyl oleate based lecithin organogels [EO/lecithin organogel] and hydrogel was investigated. The In vivo characterization of ethyl oleate based organogel study was compared with that of hydrogel.The alterations in microstructure of organogels during diffusion study were elucidated. Viscosity and micellar size of the organogel sample were estimated. The safety of optimized organogel was determined using histopathological investigation. RESULTS: The flux calculated for skin permeation ability of aceclofenac was in the order EO/lecithin organogel > hydrogel. The In vivo results also demonstrated that organogels are more effective in faster drug release as compared to hydrogels. It was observed that viscosity of gels decreased with increasing stress .The size of micellar aggregation increased with water added and has been revealed in dynamic light scattering (DLS) study. The histopathological data showed that EO/lecithin organogel were safe enough for topical purpose.

Formulation and evaluation of flurbiprofen microemulsion.

The purpose of the present study was to investigate the microemulsion formulations for topical delivery of Flurbiprofen (FP) in order to by pass its gastrointestinal adverse effects. The pseudoternary phase diagrams were developed and various microemulsion formulations were prepared using Isopropyl Myristate (IPM), Ethyl Oleate (EO) as oils, Aerosol OT as surfactant and Sorbitan Monooleate as cosurfactant. The transdermal permeability of flurbiprofen from microemulsions containing IPM and EO as two different oil phases was analyzed using Keshary-Chien diffusion cell through excised rat skin. Flurbiprofen showed higher in vitro permeation from IPM as compared to that of from EO microemulsion. Thus microemulsion containing IPM as oil phase were selected for optimization. The optimization was carried out using 2(3) factorial design. The optimized formula was then subjected to in vivo anti-inflammatory study and the performance of flurbiprofen from optimized formulation was compared with that of gel cream. Flurbiprofen from optimized microemulsion formulation was found to be more effective as compared to gel cream in inhibiting the carrageenan induced rat paw edema at all time intervals. Histopathological investigation of rat skin revealed the safety of microemulsion formulation for topical use. Thus the present study indicates that, microemulsion can be a promising vehicle for the topical delivery of flurbiprofen.

Topical delivery of aceclofenac from lecithin organogels: preformulation study.

The purpose of this research is to evaluate the suitability of lecithin organogels containing aceclofenac for topical application. The present article focuses on the preformulation part of the whole research work. Thin layer chromatography was carried out to determine lecithin's purity. The excipients for formulating lecithin organogel were screened. Lecithin organogels are thermo reversible in nature and hence gelation temperature study was carried out to determine the temperature where Sol-Gel and Gel-Sol transformation takes place. Partition coefficient of the drug was estimated. Drug solubility in plain oil and organogel containing reverse micelles was estimated. Effect of water added on the properties of lecithin organogels such as X-ray diffraction pattern, conductivity and viscosity were determined. Microscopy of the gel sample has been carried out at different magnifications. The pseudo ternary phase diagram has been constructed to determine the organogel existence region. The permeation study of aceclofenac from different concentrations of lecithin organogels [200 mM, 300 mM and 400 mM] has been determined using cellulose acetate membrane (0.45 micro) and excised rat skin. Lecithin organogel in ethyl oleate has desired stability and consistency. A single spot on the TLC plate confirms the purity of soy lecithin to be used in organogel formation. Aceclofenac solubility was found to be more in lecithin/oil reverse micellar system as compared to its solubility in oil. The X-ray diffraction pattern confirms the incorporation of water in micellar gel network. The physical properties of organogels are affected by water incorporated and concentration of gelator. The permeation of aceclofenac through artificial membrane and excised rat skin demonstrated the same trend and were in the following order 200 mM>300 mM>400 mM. The results showed that organogel exhibits useful pharmaceutical properties.

Applications of microemulsion based drug delivery system.

The use of microemulsions as drug delivery vehicle has been an exciting and attractive area of research because of its many potential and extraordinary benefits. Microemulsions offer an interesting and potentially quite powerful alternative carrier system for drug delivery because of their high solubilization capacity, transparency, thermodynamic stability, ease of preparation, and high diffusion and absorption rates when compared to solvent without the surfactant system. The oral efficacy of microemulsion has already been proved by cyclosporine formulation (Neoral), but apart from oral route, microemulsions for other routes like dermal, transdermal, ocular, vaginal, rectal, buccal, periodontal, parenteral, and nasal delivery routes have also been developed. The present review focuses on various applications of microemulsions through different above mentioned routes and also gives idea about new application of micro emulsion as oral solid dosage form, as microreactors and as blood substitute.

Advanced approaches in insulin delivery.

Diabetes is a syndrome of disordered metabolism and inappropriate hyperglycemia resulting from a deficiency of insulin secretion or insulin resistance. Insulin, a pancreatic hormone, helps to lower the blood sugar levels. The structural features of insulin and insulin receptors are summarized. Diabetic patients use insulin in the form of injections, which involves lots of pain, and a need for non-invasive, alternative mode of insulin administration is desired. These challenges have lead to attempts in insulin therapy using oral, nasal, pulmonary, rectal, transdermal, buccal, gene therapy, islet cell transplantation and diabetes vaccine. Among all the approaches pulmonary administration has achieved some clinical significance. Future approaches that can be exploited for insulin therapy in Insulin Dependent Diabetes Mellitus [IDDM] have been summarized. Insulin inhalers or tablets for IDDM are interesting alternatives.