Face Recognition Using PCA and DCT Based Approach

Face is a complex multidimensional structure and needs good computing techniques for recognition. Our approach treats face recognition as a two-dimensional recognition problem. In this thesis face recognition is done by Principal Component Analysis (PCA) and by Discrete Cosine Transform (DCT). Face images are projected onto a face space that encodes best variation among known face images. The face space is defined by eigenface which are eigenvectors of the set of faces. In the DCT approach we take transform the image into the frequency domain and extract the feature from it. For feature extraction we use two approach.. In the 1st approach we take the DCT of the whole image and extract the feature from it. In the 2nd approach we divide the image into sub-images and take DCT of each of them and then extract the feature vector from them

DEVELOPMENT AND IN VITRO, IN VIVO EVALUATION OF CONTROLLED RELEASE, BIOCOMPATIBLE NANOPARTICLES

The intention of the study was to formulate poly (D, L-lactic-co-glycolic acid) PLGA nanoparticles containing glibenclamide and to characterize by both in vitro and in vivo method. Nanoparticles were prepared by emulsion solvent evaporation technique using methanol and dichloromethane in a ratio 2:1 as solvent with (PVA/polysorbate-80) in a fixed concentration as surfactant. The prepared nanoparticles were characterized by transmission electron microscopy (TEM), differential scanning calorimetry (DSC), stability and for in vitro drug release study. The in vivo antidiabetic study along with biochemical and haematological study was also carried out using streptozotacin induced female albino rats. Stable glibenclamide loaded PLGA nanoparticles were successfully prepared by solvent evaporation technique without any incompatibility as indicated by DSC study. The drug release from prepared nanoparticles continued for 3 days in a controlled zero order fashion. The optimised formulation was able to produce significant antidiabetic activity and the activity continued for 7 days. No significant change in behavioural, biochemical and haematological parameters was observed during the study period

FORMULATION AND EVALUATION OF BILAYERED FELODIPINE TRANSDERMAL PATCHES: IN VITRO AND EX VIVO CHARACTERIZATION

Objective: Felodipine (FD) is an effective Biopharmaceutics Classification System Class II calcium channel blocker mainly used in the management of hypertension and angina pectoris. It has poor solubility and low oral bioavailability (15%). To overcome these disadvantages and to maintain constant plasma concentration for maximum therapeutic activity, there is a need to design an alternative route, that is, transdermal route. The pharmacokinetic parameters make FD a suitable candidate for transdermal delivery. The present investigation consists of the study of in vitro and ex vivo skin flux of FD from bilayered transdermal patches. Methods: The patches were fabricated by solvent casting method using hydrophilic and hydrophobic polymer with different composition. Tween 80 incorporated as solubilizer, polyethylene glycol 600 as plasticizer, menthol, eucalyptus oil, and lemongrass oil used as permeation enhancers, respectively. The prepared transdermal drug delivery system was extensively evaluated for in vitro release, ex vivo permeation through pig ear skin, moisture content, moisture absorption, water vapor transmission, and mechanical properties. The physicochemical interaction between FD and polymers was investigated by Fourier-transform infrared (FTIR) spectroscopy. Results: All the formulations exhibited satisfactory physicochemical and mechanical characteristics. A flux of 35.2 μg/cm2 h, 27.9 μg/cm2 h, and 25.25 μg/cm2 h was achieved for optimized formulations containing lemongrass oil, eucalyptus oil, and menthol, respectively, permeation enhances. Values of tensile strength (0.0652±0.034 kg/mm²) and elongation at break (0.8749±0.0.0029% mm²) revealed that formulation F9 was strong but not brittle. Drug and excipients compatibility studies showed no evidence of interaction between the active ingredient and polymers. Conclusion: Bilayered FD transdermal patches could be prepared with required flux and suitable mechanical properties

Preparation and Evaluation of Glibenclamide-Loaded Biodegradable Nanoparticles

Purpose: To formulate and evaluate glibenclamide (GB)-loaded poly(lactic-co-glycolic) acid (PLGA) nanoparticles (NPs) for controlled release. Methods: GB-loaded PLGA NPs were prepared by solvent evaporation technique using methanol/dichloromethane (2:1) and characterized by transmission electron microscopy (TEM), and differential scanning calorimetry (DSC). The effect of stirring speed (250, 1000, 1500 and 2500 rpm) and drug: polymer ratio (1:1, 1: 2, 1:3 and 2:1) on particle size, size distribution, zeta potential, drug loading, encapsulation efficiency and drug release was also studied. Results: Stable NPs were successfully prepared without any incompatibility, as indicated by TEM and DSC studies, respectively. As polymer and drug concentrations, and stirring speed increased, particle size, drug loading and encapsulation efficiency also increased. Increase in polymer concentration sustained drug release but reverse was obtained as drug concentration increased. Conclusion: Controlled release biodegradable glibenclamide NPs can be efficiently prepared by emulsification solvent evaporation method suitably modulating processing variables

APPLICATION OF CENTRAL COMPOSITE DESIGN FOR OPTIMIZATION OF EFFERVESCENT FLOATING TABLETS USING HYDROPHILIC POLYMERS

The aim of the present study was to optimize effervescent floating tablets of Cefixime Trihydrate as model drug by optimization of polymers concentration using central composite design. Mean dissolution time (MDT), time required to release 50% of drug (t50%), drug release at 2 h (R2h) and dissolution efficiency in 2 h (DE2h) were taken as target responses, where as the quantity of different polymers such as Carbopol 934P (viscoelastic agent), Sod.CMC (swelling agent) were considered as independent variables. A second-order polynomial equation was determined by the multiple regression analysis of the experimental data. The best fitting model was selected based on the comparisons of the coefficient of determination (r2), adjusted coefficient of determination (adj. r2). In addition, analysis of variance (ANOVA) was used to evaluate the statistical significance of the quadratic polynomial model. The optimum values for the critical components were obtained as 13.151% Carbopol 934P and 4.08% of Sod.CMC with predicted value of 4.926 h MDT, 5.257 h t50%, 27.6316% R2h and 16.5951% DE2h from desirability and overlay plot. Further the reliability of the model was checked by validating the observed responses from optimized formula. The drug release from characteristics of all formulations followed Higuchi model with a non-Fickian diffusion mechanism. Further the data of FTIR study showed there was no interaction of drug and excipients used for the preparation of floating tablets.                                      Key words: Central composite design, Cefixime Trihydrate, Mean dissolution time, Fickian diffusion, dissolution efficienc

Effect of Additives on the Physicochemical and Drug Release Properties of Pioglitazone Hydrochloride Spherical Agglomerates

Purpose: To prepare and evaluate spherical agglomerates of pioglitazone hydrochloride (PGH) for direct compression with different additives. Method: Spherical agglomerates of pioglitazone hydrochloride were prepared by emulsion solvent diffusion method with and without additives (polyethylene glycol 6000, polyvinyl pyrrolidone, β cyclodextrin, Eudragit RS100, low acyl gellan gum and xanthan gum) using methanol, chloroform and water as good solvent, bridging liquid and poor solvent respectively. The agglomerates were evaluated for compressibility, solubility and dissolution rate and also by scanning electron microscopy (SEM), Xray powder diffraction (XRPD), differential scanning calorimetry (DSC) and fourier transforms infrared spectroscopy (FTIR). Results: The particle size, flowability, compactibility, packability, solubility and dissolution rate of plain agglomerates and agglomerates with additives, except polyvinyl pyrrolidone, were enhanced compared with the original crystals of pioglitazone hydrochloride. This might be attributed to their large size (10 x original PGH crystals), spherical shape, enhanced fragmentation during compaction (yield pressure increased from 22.6 to 29.3 MPa) and reduced elastic recovery of compacts (from 8.1 to 5.5 %) compared to the original drug crystals. XRPD and DSC studies indicate polymorphic transition of PGH in all agglomerates from form II to I during recrystallization; FTIR spectra show that this was not associated with any chemical transition. Conclusion: The findings indicate that spherical crystallization by emulsion solvent diffusion method to produce agglomerates containing selected additives is a satisfactory approach for the formulation of directly compressed pioglitazone hydrochloride tablets

Formulation and in vitro evaluation of Eudragit® microspheres of stavudine

Purpose: The aim of this study was to formulate and evaluate microencapsulated controlled release preparations of a highly water-soluble drug, stavudine, using Copolymers synthesized from acrylic and methacrylic acid esters (Eudragit RS 100 and RL 100) as the retardant material. . Methods: Microspheres were prepared by solvent evaporation method using an acetone / liquid paraffin system. Magnesium stearate was used as the droplet stabilizer and n-hexane was added to harden the microspheres. The prepared microspheres were characterized for their micromeritic properties and drug loading, as well by fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry, x-ray powder diffractometry and scanning electron microscopy. The in vitro release studies were performed in pH 6.8, phosphate buffer. Results: The prepared microspheres were white, free flowing and spherical in shape. The drug-loaded microspheres showed 67-91% of entrapment and release was extended upto 6 to 8 h. The infrared spectra and differential scanning calorimetry thermographs showed stable character of stavudine in the drug-loaded microspheres and revealed the absence of drug-polymer interactions. X-ray diffraction patterns showed that there was decrease in crystallinity of the drug. Scanning electron microscopy study revealed that the microspheres were spherical and porous in nature. Conclusion: The best-fit release kinetics was achieved with Higuchi plot followed by zero order and First order. The release of stavudine was influenced by the drug to polymer ratio and particle size & was found to be diffusion controlled

Development of Ultraviolet Spectrophotometric Method for Analysis of Lornoxicam in Solid Dosage Forms

Purpose: An ultraviolet spectrophotometric system was developed and validated for the quantitative determination of lornoxicam in solid dosage forms. Methods: Lornoxicam was dissolved in 0.01M NaOH and analysed using ultraviolet (UV) spectrophotometry. Various analytical parameters such as linearity, precision, accuracy, limit of detection (LOD) and limit of quantification (LOQ) were determined according to International Conference on Harmonization (ICH) guidelines. Results: Absorbance maximum in 0.01M NaOH was 377 nm. Beer’s law was obeyed over the concentration range of 2 - 20 mg/ml with a correlation coefficient (r2) value of 0.999. Percent range of error was 0.344 and 0.261 at 0.05 and. 0.01 confidence limits, respectively. Intra- and inter-day precision (% RSD) at different concentration levels were <2 %, indicating that the proposed derivative spectrophotometric method is highly reproducible during one run and between different runs; LOD and LOQ were 0.105 and 0.318 μg/ml, respectively signifying that it can be adopted for routine quality testing. Mean recovery was 100.82 % for tablets. Low values of % RSD indicate the reliability of the proposed method Conclusion: The proposed method is highly sensitive, precise, accurate, cost-effective, reliable and rapid for the estimation of lornoxicam in solid dosage forms