Application of Response Surface Methodology Using Face-centered Central Composite Design for Studying Long-Term Stability of Gliclazide-Loaded Multiparticulate Systems

The appropriate design of experiments (DoE) could support post-approval lean-stability approaches. A three-factor three-level face-centered design was constructed to evaluate the long-term stability of gliclazide (GLZ) alginate-gelatin beads. The formulation variables were GLZ%(X1), alginate:gelatin ratio(X2), and glutaraldehyde%(X3). The studied responses included GLZ release at predefined intervals in 0.1 N HCl (2 h) followed by phosphate buffer (pH 7.4). Model-dependent and independent approaches were utilized for comparison. DoE-model validation and reduction were implemented. All the studied formulations showed non-significant changes in the particle size (p > 0.05) and most of them showed similar release profiles before and after storage. The directions of the relationships between the factors' main effects and the responses (Y1:Q0.5h, Y2:Q2h, and Y3:Q4h) remained unchanged after storage. The optimal factor settings based on the proposed optimization criteria were defined. The optimized formulations (OP-1 and OP-2) showed non-significant changes in the particle size after storage. The release profiles and kinetics of OP-1 and OP-2 remained unchanged after storage. No chemical change was indicated (FT-IR). DSC-thermograms of OP-1 indicated GLZ conversion to a more stable polymorph after storage. While OP-2 showed a change in GLZ crystallinity. The stored and fresh beads' surfaces after GLZ release were almost similar. DoE could be utilized to evaluate, optimize, and predict the effects of different formulation variables on the long-term stability of GLZ alginate-gelatin beads.

Optimization of Meloxicam Solid Dispersion Formulations for Dissolution Enhancement and Storage Stability Using 33 Full Factorial Design Based on Response Surface Methodology

This study aimed to formulate and optimize solid-dispersion of meloxicam (MX) employing response-surface-methodology (RSM). RSM allowed identification of the main effects and interactions between studied factors on MX dissolution and acceleration of the optimization process. 3³ full factorial design with 27 different formulations was proposed. Effects of drug loading percentage (A), carriers' ratio (B), method of preparation (C), and their interactions on percent MX dissolved after 10 and 30 min (Q_10min & Q_30min) from fresh and stored samples were studied in distilled water. The considered levels were 2.5%, 5.0%, and 7.5% (factor A), three ratios of Soluplus®/Poloxamer-407 (factor B). Physical mixture (PM), fusion method (FM), and hot-melt-extrusion (HME) were considered factor (C). Stability studies were carried out for 3 months under stress conditions. The proposed optimization design was validated by 3-extra checkpoints formulations. The optimized formulation was selected via numerical optimization and investigated by DSC, XRD, PLM, and in vitro dissolution study. Results showed that HME technique gave the highest MX dissolution rate compared to other techniques (FM & PM). At constant level of factor (C), the amount of MX dissolved increased by decreasing MX loading and increasing Soluplus in carriers' ratio. Actual responses of the optimized formulation were in close consistency with predicted data. Amorphous form of MX in the optimized formulation was proved by DSC, XRD, and PLM. Selected factors and their levels of the optimization design were significantly valuable for demonstrating and adapting the expected formulation characteristics for rapid dissolution of MX (Q_10min= 89.09%) from fresh and stored samples.

Preparation, characterization and in-Vitro/in-Vivo evaluation of meloxicam extruded pellets with enhanced bioavailability and stability

OBJECTIVE

The present study involved enhancement of Meloxicam (MX) oral absorption for rapid onset of therapeutic action. A challenging approach using hot-melt-extrusion technique (HME) for production of stable novel preparation of MX pellets was successfully proposed.

METHODS

Manipulating HME processing parameters (barrel-temperatures and screw-speed) and proper polymer(s) selection (Soluplus, a combination of Soluplus/Poloxamar and Polyethylene Glycol 6000) were the main strategies involved for productive extrusion of MX. Evaluation of MX solid-state (TGA, DSC and PLM), absolute percent crystallinity, in-vitro dissolution (in acidic/aqueous pHs), and stability testing in accelerated conditions up to 6-months as well as a long-term shelf for 36-months were performed. A comparative bioavailability study of selected MX-Pellets was carried-out against the innovator product (Mobic^®) in 6 healthy volunteers under fed-conditions.

RESULTS

TGA, DSC and PLM analyses proved the dispersion of MX in amorphous-state within polymeric matrix by HME. MX/Soluplus pellets exhibited the lowest crystallinity % and best dissolution performance among other polymers in both pHs. In addition, presence of Soluplus safeguards final pellets stability under different storage conditions. MX rate of absorption (T_max) from Soluplus-based pellets attained a value of 45 min, which was 6-times faster than Mobic^® (4.5 hr).

CONCLUSION

A promising oral MX formula prepared by HME was successfully developed with a rapid onset of analgesic action (T_max of 45 mins; almost 2-times faster than reported intramuscular injection), hence appropriate in the early relief of pain associated with rheumatoid arthritis and osteoarthritis. Moreover, the proposed formula was physico-chemically stable up to 36 months of shelf-life storage.