Development and Optimization of Inhalable Levofloxacin Nanoparticles for The Treatment of Tuberculosis.

BACKGROUND: Levofloxacin has been recommended by the WHO for the treatment of pulmonary tuberculosis and inhalable delivery of levofloxacin can be advantageous over conventional delivery. OBJECTIVE: This study aimed to develop and optimize inhalable levofloxacin Loaded Chitosan Nanoparticles (LCN). The objective was to achieve the mean particle size of LCN less than 300nm, sustain the drug release up to 24 h, and achieve MMAD of LCN of less than 5µm. METHODS: LCN were prepared by ionic gelation of chitosan with sodium tripolyphosphate (STPP) and subsequent lyophilization. A Plackett Burman screening design, 32 full factorial design, and overlay plots were sequentially employed to optimize the formulation. The mean particle size, % entrapment efficiency, in vitro drug release, and minimum inhibitory concentration were all evaluated. RESULTS: The Pareto chart from the Placket Burman screening design revealed that the concentrations of chitosan and STPP was found to be significant (p < 0.05). Further analysis by 32 full factorial design revealed that F-ratio for each model generated was found to be greater than the theoretical value (p < 0.05), confirming the significance of each model. CONCLUSION: The optimized formulation showed a mean particle size of 171.5 nm, sustained the drug release up to 24 h in simulated lung fluid, and revealed MMAD of 3.18 µm, which can confirm delivery of the drug to the deep lung region. However, further in vivo studies are required to design a suitable dosage regimen and establish the fate of nanoparticles for safe and efficacious delivery of the drug.

Formulation and optimization of microsponge-loaded emulgel to improve the transdermal application of acyclovir-a DOE based approach.

The cutaneous penetration of acyclovir from the conventional topical formulations such as cream and ointments is poor due to low water solubility and low octanol buffer partition coefficient of the drug. The present investigation was aimed to prepare acyclovir-loaded microsponge-based emulgel to improve its topical delivery. The microsponges were prepared by the quasi-emulsion diffusion method. The central composite design was employed to investigate the effect of changes in various formulation and process parameters on critical product attributes. Homogenization speed (X1), drug/polymer ratio (X2), and concentration of PVA (X3) were selected as independent variables while particle size,b% yield, % drug loading efficiency, % entrapment efficiency, the drug released at 0.25 h and 6 h were selected as response variables. The regression analysis proved a significant effect of all the independent variables on the dependent variables (p < 0.05). All the designed batches released more than 40% drug in less than 1 h and were also able to sustain the drug release for more than 6 h. Based on the solution suggested by the software, the optimized batch was prepared with 1000-rpm homogenization speed, 1.6:1 drug/polymer ratio, and 0.088% of PVA. The optimized microsponge-loaded emulgel had acceptable viscosity (10,897 to 12,416 centipoise), spreadability (32.5 to 36.57 g × cm/s), pH (between 6 and 7), and drug content (93 to 95%). The results of the ex vivo permeation study proved significant improvement in drug permeation from optimized microsponge-loaded emulgel compared to the marketed formulation (f2 < 50).

Preparation and optimization of multi-functional directly compressible excipient: an integrated approach of principal component analysis and design of experiments.

Developing a new excipient and obtaining its market approval is an expensive, time-consuming, and complex process. The application of a multivariate analytical approach - principal component analysis (PCA) - in combination with the design of experiments (DoE) approach can make the process of developing co-processed excipient cost-effective and rapid. The present investigation was aimed to demonstrate the applicability of the DoE approach and PCA in developing a co-processed excipient by using the spray drying technique. The preliminary studies suggested a significant effect of inlet air temperature (X 1) and polymer ratio [chitosan chlorhydrate (CC): mannitol - X 2) on critical product characteristics so they were selected as independent variables in 32 full factorial design. The result of regression analysis suggested a significant effect of both independent variables on all response variables. The PCA of practically obtained value suggested a strong effect of all the selected response variables on the model. The prepared co-processed excipient had better tableting properties compared to the physical mixture of excipients and was able to accommodate more than 80% drug without compromising the flow property and compressibility. The present investigation successfully proved the applicability PCA and DoE approach as an effective and rapid tool for optimizing process parameters and formulation composition for preparing a directly compressible co-processed excipient.

Formulation and optimization of liquisolid compact for enhancing dissolution properties of efavirenz by using DoE approach.

Efavirenz displays low and variable bioavailability because of its poor aqueous solubility and high log P-value. The present investigation was aimed to improve the dissolution profile of efavirenz by using a simple, scalable and cost-effective technique of liquisolid compact. The drug was dissolved in Trancutol-HP for preparing the liquid medicament which was subsequently mixed with carrier and coating material to make free-flowing and compressible powder. 32 full factorial design was used to optimize the formulation in which the Neusilin US2/Corn starch ratios and carrier/coating material ratio were selected as independent variables. The results of in-vitro dissolution test proved that liquisolid compacts have significantly higher dissolution rate than tablets containing pure drug. Results of DSC and XRD studies suggested that the high dissolution of the drug from the liquisolid compacts was possibly because of the drug either being in an amorphous state or being molecularly dispersed within the internal matrix of compacts.

Pharmacokinetics and in vivo distribution of optimized PLGA nanoparticles for pulmonary delivery of levofloxacin.

OBJECTIVES: The aim of this study was to develop and optimize levofloxacin loaded PLGA nanoparticles (LN) for pulmonary delivery employing screening and experimental design and evaluate their in-vitro and in-vivo performance. The objective was to achieve Mass Median Aerodynamic Diameter (MMAD) of LN of less than 5µm, sustain the drug release up to 120 h and a higher AUC/MIC at the site of action. METHODS: LN were prepared by modified emulsion solvent evaporation technique employing high speed homogenization, probe sonication and subsequent lyophilization. KEY FINDINGS: The Pareto chart from Placket Burman screening design revealed that homogenization speed and amount of PLGA were found to be significant (P < 0.05). Further analysis by 3 full-factorial design revealed that F-ratio was found to be far greater than the theoretical value (P < 0.05) for each regression model. CONCLUSION: The optimized formulation with desirability value 0.9612 showed mean particle size of 146 nm, MMAD of 4.40 µm and sustained the drug release up to 120 h in simulated lung fluid. Augmentation in Cmax (1.71-fold), AUC 0-∞ (5.46-fold), Mean Residence Time (6.64-fold) and AUC/MIC (6.21-fold) of LN through pulmonary route was found to significantly higher (P < 0.05) than levofloxacin (p. o.).

Co-processing of cefuroxime axetil by spray drying technique for improving compressibility and flow property.

The aim of the present investigation was to improve the compressibility and flow property of cefuroxime axetil by co-processing it with mannitol and chitosan chlorhydrate using spray drying method. 32 full factorial design, having inlet air temperature and mannitol: chitosan chlorhydrate ratio as independent variables was used for the optimization. Statistical analysis of obtained results revealed that both independent variables had significant effect on response variables (p value < .05). Evaluation of dependent variables suggested, excellent to good flow properties (angle of repose, Carr's index, and Hausner's ratio) for all prepared batches. Desirability function was used for the selection of the optimized batch which was evaluated for Kawakita's equation, Heckel's plot to assess compression behavior of co-processed product under applied pressure. Result of this analysis revealed that the optimized batch product had better compressibility than physical mixture. The tablets prepared by directly compressing spray-dried product, exhibited excellent tensile strength acceptable friability (<1%) and similar release profile when compared with marketed formulation (Similarity factor 89.24 and dissimilarity factor 1.79). So the results of the present investigation concluded that cefuroxime axetil was successfully co-processed with above mentioned excipients by using spray drying method to make it directly compressible.

Microemulgel of Voriconazole: an Unfathomable Protection to Counter Fungal Contagiousness.

BACKGROUND: Fluconazole and ketoconazole both have poor minimum inhibitory concentration than voriconazole. Voriconazole had serious side effects in oral and intravenous doses. It has poor water solubility. The objective of the study was to prepare and optimize microemulgel of voriconazole for topical delivery. AIM: Formulation, development, and evaluation of voriconazole microemulgel for topical delivery. METHODS: Oil and emulsifi ers selected were on the basis of equilibrium solubility study and emulsification property respectively. The pseudo-ternary plot and constrained simplex lattice design were applied for preparation of microemulsions. Microemulsions were subjected to micelle size, zeta potential, polydispersity index, and in vitro study. They were optimized by Design-Expert® 9.0.3.1 software. Formulation, development, evaluation and optimization of microemulgel were carried out. Microbial assay of an optimized batch of microemulgel was performed. RESULTS: Solubility of voriconazole in Parker Neem® oil was 7.51±0.14 mg/g. Acrysol™K-150: PEG-400 in 4:1 ratio had the highest area for microemulsion. 59.2% Acrysol™K-150, 14.8% PEG-400, 11% Parker Neem® oil, 15% rose water, and 1% voriconazole as an optimized batch of microemulsion was selected for preparation of microemulgel. Carbomer 934P found a good gelling agent in 0-2% w/w concentration. An optimized batch of microemulgel had 0.974 desirability value. An optimized batch of microemulgel and Nizral® cream had 37.32±0.63% and 26.45±0.63% zones of inhibition. CONCLUSION: Topical antifungal treatment was successfully achieved with voriconazole microemulgel.

Development and Characterization of Multifunctional Directly Compressible Co-processed Excipient by Spray Drying Method.

The present investigation was carried out to develop and characterize a multifunctional co-processed excipient for improving the compressibility of poorly compressible drugs. Etodolac was used as a model drug. Microcrystalline cellulose (MCC), lactose monohydrate (lactose), and StarCap 1500 (StarCap) were selected as components of the co-processed excipient. The spray drying method was used for co-processing of excipients. D-optimal mixture design was applied to optimize the proportion of component excipients. Statistical analysis of the D-optimal mixture design revealed that all response variables were significantly affected by the independent variables (p value < 0.05). Optimized composition was obtained from the desirability function. The optimized composition of the co-processed excipient was found to be 30% MCC, 25% lactose, and 45% StarCap. This optimized batch was evaluated for flow properties, compressibility parameters such as Kawakita's and Kuno's equation and Heckel's equation, and dilution potential. Evaluation parameters for flow properties (angle of repose, Carr's index, and Hausner's ratio) suggested excellent flow character. The parameters of Kawakita's and Kuno's equation and Heckel's equation suggested improvement in the compressibility of the model drug. Dilution potential was found to be 40%, and based on that, tablets of the model drug were formulated and evaluated for general evaluation parameters of tablets. All the parameters were found to be within the acceptance criteria which concluded that the multifunctional directly compressible co-processed excipient was prepared successfully that improved the compressibility of the poorly compressible model drug etodolac along with spray drying as an efficient method for the preparation of co-processed excipient.

Design, Optimization, and Evaluation of Lurasidone Hydrochloride Nanocrystals.

The present investigation was carried out to design, optimize, and evaluate lurasidone hydrochloride nanocrystals for improving its solubility and dissolution characteristics. Nanocrystals were prepared by media milling technique using zirconium oxide beads with 0.1 mm diameter. Various stabilizers, viz. poloxamer 188, PVP K30, SLS, HPMC E15, and PVP S 630 D, were evaluated to stabilize the nanocrystals. The Pareto chart obtained through Plackett-Burman screening design revealed that HPMC E 15 showed the highest standardized effect (p value <0.05) on percent dissolution efficiency at 2 min. In subsequent studies, a 3(2) factorial design was employed to quantify the effect of two independent variables, namely amount of stabilizer and milling time on predetermined response variables mean particle size, saturation solubility, and percent dissolution efficiency at 2 min. Statistical analysis of the factorial design revealed that all predetermined response variables were significantly dependent (p value <0.05) on the independent variables. The observed response of the optimized batch prepared as per the desirability function was in close agreement with predicted response, and mathematical model generated was validated. The optimized batch was lyophilized, and X-ray powder diffraction studies indicated that there was no substantial change in crystallinity of the drug. The optimized formulation showed mean particle size of 228 nm and released almost all the drug within first 5 min. Since the crystallinity of the drug is maintained, improvement in saturation solubility and dissolution efficiency could be attributed to decrease in mean particle size of the drug.

Formulation, evaluation and optimization of the felodipine nanosuspension to be used for direct compression to tablet for in vitro dissolution enhancement.

The oral bioavailability of felodipine very low, nearly just 15% due to its limited solubility and high first pass metabolism. The present study was aimed to improve the rate of the dissolution of Felodipine by formulating a nano suspension of it by combination of high-speed homogenization and media milling technique. Stabilizers screened in this study were Poloxamer 401, HPMC K15M and Tween 80. Concentration of stabilizers were optimized by simplex lattice design for Mean Particle Size (MPS), Poly dispersity Index (PDI), saturation solubility (SS) and in vitro drug release in 30 min. The particle size of 201 nm and increase in saturation solubility of nearly 9 folds were obtained for optimize batch. The prepared nano suspension of drug was used as a granulating agent to form tablets having Microcrystalline Cellulose (MCC) as diluents. In vitro Drug release study indicates that more than 90% of the drug releases in 30 minutes. Preparing the nano suspension of the low solubility drug is an effective method to increase its saturation solubility. This nano suspension can be prepared effectively by combination of high-speed homogenization and media milling which is also very economical as well.

Development and optimization of press coated tablets of release engineered valsartan for pulsatile delivery.

The present work is aimed to develop and optimize pulsatile delivery during dissolution of an improved formulation of valsartan to coordinate the drug release with circadian rhythm. Preliminary studies suggested that ß cyclodextrin could improve the solubility of valsartan and showed AL type solubility curve. A 1:1 stoichiometric ratio of valsartan to ß cyclodextrin was revealed from phase solubility studies and Job's plot. The prepared complex showed significantly better dissolution efficiency (p < 0.05) compared to pure drug, which could be due to the formation of inclusion complex as revealed from FTIR and DSC studies. Continuous dissolution-absorption studies revealed that absorption of drug from valsartan ß cyclodextrin complex was significantly higher (p < 0.05) compared to pure drug, in second part press-coated tablets of valsartan ß cyclodextrin complex were subsequently prepared and application of the Plackett-Burman screening design revealed that HPMC K4M and EC showed significant effect on lag time. A 3(2) full factorial design was used to measure the response of HPMC K4M and EC on lag time and time taken for 90% drug release (T90). The optimized batch prepared according to the levels obtained from the desirability function had a lag time of 6 h and consisted of HPMC K4M:ethylcellulose in a 1:1.5 ratio with 180 mg of coating and revealed a close agreement between observed and predicted value (R(2 )= 0.9694).

Self-nanoemulsifying drug delivery system of glimepiride: design, development, and optimization.

The objective of the present investigation was to develop and characterize the self-nanoemulsifying drug delivery system (SNEDDS) of glimepiride, a poorly soluble drug. Solubility of glimepiride in various vehicles was determined, and ternary phase diagrams were constructed using a suitable oil, surfactant, and cosurfactant system to find out the efficient self-emulsification system. A three factor, three level Box-Behnken statistical design was employed to explore the main and interaction effect of independent variables, namely X1 (amount of Capmul MCM), X2 (amount of Acrysol K 140), and X3 (amount of Transcutol P). Percent transmittance value (Y1), droplet diameter (Y2), and percent drug released at 5 min (Y3) were the dependent variables. Formulation optimization was carried out to optimize the droplet diameter and percent drug dissolved at 5 min. The batch prepared according to the optimized formulation showed a close agreement between observed and predicted values. Box-Behnken statistical design allowed us to understand the effect of formulation variables on the rapid dissolution of drug from SNEDDS and to optimize the formulation to obtain a rapid drug dissolution at 5 min. LAY ABSTRACT: A self-nanoemulsifying drug delivery system of glimepiride has been design, developed, and optimized. A three factor, three level Box-Behnken statistical design was employed to explore the main and interaction effect of independent variables, namely X1 (amount of Capmul MCM), X2 (amount of Acrysol K 140), and X3 (amount of Transcutol P). Percent transmittance value (Y1), droplet diameter (Y2), and percent drug released at 5 min (Y3) were the dependent variables. The Capmul MCM-Akcrysol K 140-Transcutol system was found to be the suitable ternary system that was able to release almost 80% of drug within the first 5 min. The improved dissolution of glimepiride might improve patient compliance.

Formulation and evaluation of glipizide floating-bioadhesive tablets

The purpose of this study was formulation and in vitro evaluation of floating-bioadhesive tablets to lengthen the stay of glipizide in its absorption area. Effervescent tablets were made using chitosan (CH), hydroxypropyl methylcellulose (HPMC), carbopolP934 (CP), polymethacrylic acid (PMA), citric acid, and sodium bicarbonate. Tablets with 5 percent effervescent base had longer lag time than 10 percent. The type of polymer had no significant effect on the floating lag time. All tablets floated atop the medium for 23-24 hr. Increasing carbopolP934 caused higher bioadhesion than chitosan (p < 0.05). All formulations showed a Higuchi, non-Fickian release mechanism. Tablets with 10 percent effervescent base, 80 percent CH/20 percent HPMC, or 80 percent CP/20 percent PMA seemed desirable.

Formulation and evaluation of stomach-specific amoxicillin-loaded carbopol-934P mucoadhesive microspheres for anti-Helicobacter pylori therapy.

The purpose of this research was to formulate and systemically evaluate in vitro and in vivo performances of mucoadhesive amoxicillin microspheres for the potential use in the treatment of gastric and duodenal ulcers, which were associated with Helicobacter pylori. Amoxicillin mucoadhesive microspheres containing carbopol-934P as mucoadhesive polymer and ethyl cellulose as carrier polymer were prepared by an emulsion-solvent evaporation technique. Results of preliminary trials indicate that quantity of emulsifying agent, time for stirring, drug-to-polymers ratio and speed of rotation affected the characteristics of microspheres. Microspheres were discrete, spherical, free flowing and showed a good percentage of drug entrapment efficiency. An in vitro mucoadhesive test showed that amoxicillin mucoadhesive microspheres adhered more strongly to the gastric mucous layer and could retain in the gastrointestinal tract for an extended period of time. A 3(2) full factorial design was employed to study the effect of independent variables, drug-to-polymer-to-polymer ratio (amoxicillin-ethyl cellulose-carbopol-934P) (X(1)) and stirring speed (X(2)) on dependent variables, i.e. percentage mucoadhesion, drug entrapment efficiency, particle size and t(80). The best batch exhibited a high drug entrapment efficiency of 56%; mucoadhesion percentage after 1 h was 80% and the particle size was 109 µm. A sustained drug release was obtained for more than 12 h. The drug-to-polymer-to-polymer ratio had a more significant effect on the dependent variables. The morphological characteristics of the mucoadhesive microspheres were studied under a scanning electron microscope. In vitro release test showed that amoxicillin released slightly faster in pH 1.2 hydrochloric acid than in pH 7.8 phosphate buffer. In vivo H. pylori clearance tests were also carried out by administering amoxicillin powder and mucoadhesive microspheres to H. pylori infectious Wistar rats under fed conditions at single dose or multiple dose(s) in oral administration. The results showed that amoxicillin mucoadhesive microspheres had a better clearance effect than amoxicillin powder. In conclusion, the prolonged gastrointestinal residence time and enhanced amoxicillin stability resulting from the mucoadhesive microspheres of amoxicillin might make a contribution to H. pylori complete eradication.