Sandipan Dasgupta

Objective: A simple, reliable, sensitive and validated reversed phase-high performance liquid chromatography (RP-HPLC) method was developed for quantification of lornoxicam (LX) in rat plasma.Methods: Solid lipid nanoparticle (SLN) and nanostructured lipid carriers (NLC) gel formulations containing lornoxicam were prepared using high-speed homogenization followed by ultra-sonication. Pharmacokinetic study of formulated LX loaded SLN and NLC were performed on Wister albino rats.Results: The chromatographic separation was performed on hypersil octadecylsilane (ODS)-18 column using a mobile phase of 10 mmol. Phosphate buffer (pH, 4.5) and acetonitrile (65:35 v/v). Elute was monitored at 377 nm with a flow rate of 1 ml/min. Calibration curve was linear over the concentration range of 25.38–2046.45 ng/ml. Retention times of LX and internal standard (piroxicam) were 9.3 and 10.2 min, respectively. Maximum plasma drug concentration, the area under the plasma drug concentration versus time curve and elimination half-life for LX loaded SLN gel were found 6381.51±971.27ng/ml, 19917.21±7111.24 ng h/ml and 7.27±1.21h and 8558.13±1564.08 ng/ml, 21317.99±4568.71 ng/ml and 6.22±2.16 h. respectively. In vivo in vitro correlation study, the fraction of drug dissolved from nanoparticle in pH 7.4 was plotted against the fraction of drug absorbed and a linear correlation (R2= 0.9987) was obtained.Conclusion: A novel simple, simple, sensitive, precise, rapid, accurate, and economical and reliable RP-HPLC method was developed and validated for the estimation of LX in rat plasma.

The objective of this work was to increase the solubility, in vitro skin permeability of lornoxicam from semisolid topical formulations and also to investigate the in vivo potential of nanoemulsion formulation. Optimized lornoxicam loaded nanoemulsion was prepared successfully by spontaneous self-emulsification method and the size of the stable formulations was found within the range of 102 to 200 nm. The stable nanoemulsion formulations characterized for viscosity, droplet size, transmission electron microscopy (TEM) and refractive index. In vitro permeation rate of nanoemulsion and conventional gel of lornoxicam (LX) were determined. Prmeability parameters like steady-state flux (J_ss), permeability coefficient (K_p), and enhancement ratio (E_r) were significantly increased in nanoemulsion NE8 and the nanogel NG8 as compared to conventional gel (LG). In vivo studies revealed a significant increase in anti-inflammatory effects as compared with conventional gel of LX. The anti-inflammatory effects of formulation NG8 showed a significant increase in percent inhibition value when compared with control, this difference was found to be highly significant (p<0.001). This work shows for the first time that lornoxicam can be formulated into nanoemulsions and may show promise in enhancing solubility and permeation.

Solid lipid nanoparticles (SLN) are very potential formulations for topical delivery of anti-inflammatory and anti-arthritic drugs. The solid state of the lipid particles enable efficient drug encapsulation and controlled drug release. In the present study, the evaluation of different formulation parameters based on variation of concentration of lipid and cosurfactant was studied. The SLN gel formulations of the dispersions were compared to the SLN dispersions and with the marketed gel of aceclofenac. The SLNs were prepared by high speed homogenization and ultra-sonication method with fixed amount of aceclofenac (10%) and pluronic F68 (1.5%). The particle size, zeta potential and span of developed formulations was found to be within the range of 123 nm to 323 nm, -12.4 to -18.5 and 0.42 to 0.86 respectively as the lipid concentration was increased from 7.5% to 40%. The highest entrapment efficiency was found to be 75% with the formulation having lipid concentration of 30% and 0.85% of phospholipon 90G. Permeation rate and controlled release property of xanthan gum loaded SLN gel formulations and SLN dispersion was studied through excised pig skin for 24hr. The drug release of SLN gel formulations was better controlled as compare to SLN dispersions. In vivo anti-inflammatory study showed that action of aceclofenac was enhanced for SLN dispersion and gel formulations. The results indicated the superiority of SLN based formulations for topical delivery of aceclofenac.

The aim of the present study was to investigate the potential of a nanoemulsion for topical delivery of aceclofenac using different excipients having optimum emulsifying ability rather than their solubilizing capacity. The oil-in-water nanoemulsions were prepared by screening the excipients from the nanoemulsion region of pseudoternary phase diagram. The prepared nanoemulsions were subjected to different thermodynamic stability tests. The nanoemulsion formulations that passed thermodynamic stability tests were characterized for viscosity, droplet size, transmission electron microscopy, refractive index and in vitro skin permeation. The in vitro skin permeation profile of optimized nanoemulsion formulation (NE31, containing 23.85% Polyoxy-35-castor oil, 7.95% PEG 400 and 13.6% Triacetin) was compared with that of nanoemulsion gel (NG31) and marketed gel formulation (HIFENAC GEL (HIG)). In vivo anti-inflammatory efficacy studies were also carried out for NE31, NG31 and HIG. The significant (p < 0.001) increase in in vitro permeability and in vivo anti-inflammatory efficacy of the NG31 formulation was observed as compared with HIG formulation. It can be concluded that the selection of surfactant and cosurfactant on the basis of their emulsification capabilities other than the solubilizing capacity of drug is an important criterion for the formulation of nanoemulsion.