GSK-3 Inhibitors as New Leads to Treat Type-II Diabetes

In India as well as globally, diabetes is in a state of high risk and next to cardiovascular disease. As per the WHO, the risk of diabetes is expected to rise about 511 million by 2030. In quest of novel targets for type-2 diabetes, many targets were elucidated, such as Glycogen Synthase Kinase-3 (GSK-3), Dipeptidyl Peptidase (DPP-IV), PPAR-γ, α-Glucosidase, α-Amylase, GLP-1, and SGLT. Among the targets, GSK-3 was reported to be an effective target for the treatment of diabetes. In the metabolism of glycogen, GSK is a regulatory enzyme for the biosynthesis of glycogen (glycogenesis). It catalyzes the synthesis of a linear unbranched molecule with 1,4-α-glycosidic linkages. GSK-3 family has two isoenzymes, namely α and β, which differ in their Nand C- terminal sequences and are semi-conservative multifunctional serine/threonine kinase enzymes. In this chapter, we discuss an overview of general diabetic mechanisms and how GSK-3 modulation may influence these processes. Mutation in the GSK-3 complex causes diabetes. Synthetic and natural scaffolds modulate GSK-3 against diabetes and leading to its optimization for the development of GSK-3 inhibitors. This review mainly focuses on the development of GSK-3 inhibitors and highlights current and potential future therapeutic approaches that support the notion of targeting glucose metabolism with novel antidiabetic agents.

Improved Dissolution Rate and Intestinal Absorption of Fexofenadine Hydrochloride by the Preparation of Solid Dispersions: In Vitro and In Situ Evaluation

The objective of this study was to enhance dissolution and permeation of a low soluble, absorbable fexofenadine hydrochloride (FFH) by preparing solid dispersions using polyethylene glycol 20,000 (PEG 20,000) and poloxamer 188 as carriers. The phase solubility measurement for the supplied FFH revealed a linear increase in the solubility of fexofenadine with increasing carrier concentration in water (1.45 mg/mL to 11.78 mg/mL with 0% w/v to 30% w/v PEG 20,000; 1.45 mg/mL to 12.27 mg/mL with 0% w/v to 30% w/v poloxamer 188). To select the appropriate drug carrier concentration, a series of solid dispersions were prepared in the drug carrier weight ratios of 1:1, 1:2 and 1:4 by fusion method. The solid dispersions composed of drug carrier at 1:4 weight ratio showed highest dissolution with the time required for the release of 50% of the drug <15 min compared to the supplied FFH (>120 min). The intestinal absorption study presented a significant improvement in the absorption of drug from the solid dispersions composed of poloxamer 188 than PEG 20,000. In summary, the solid dispersions of FFH prepared using PEG 20,000 and poloxamer 188 demonstrated improved dissolution and absorption than supplied FFH and could be used to improve the oral bioavailability of fexofenadine.

A pH-triggered delayed-release chronotherapeutic drug delivery system of aceclofenac for effective management of early morning symptoms of rheumatoid arthritis

CONTEXT

Rheumatoid arthritis (RA) is differentiated as an early morning exacerbation of the core arthritis condition associated with increase in pain and stiffness in joints and necessitate for medication.

OBJECTIVE

The aim of the present work was to develop and optimise a pH-triggered delayed-release colon-specific aceclofenac microspheres and to accomplish chronotherapy of RA.

METHODS

A 3-factor, 3-level Box-Behnken design (BBD) was used to optimise selected variables. Developed formulation was evaluated for in vivo delayed response and anti-arthritis activity in rats.

RESULTS

The particle size and encapsulation efficacy of these microspheres were 117.36 ± 10.54 µm and 85.06 ± 5.85%, respectively. Optimised formulation was analysed by SEM, DSC, X-RPD and FTIR. The in vivo evaluation revealed delayed anti-inflammatory activity in carrageenan-induced rats and anti-arthritic activity in freund's adjuvant-induced arthritis rats.

CONCLUSION

The optimised aceclofenac microspheres formulation is potential for the chronotherapy of early morning symptoms of RA.

Pharmacokinetics of colon-specific pH and time-dependent flurbiprofen tablets

Present research deals with the development of compression-coated flurbiprofen colon-targeted tablets to retard the drug release in the upper gastro intestinal system, but progressively release the drug in the colon. Flurbiprofen core tablets were prepared by direct compression method and were compression coated using sodium alginate and Eudragit S100. The formulation is optimized based on the in vitro drug release study and further evaluated by X-ray imaging and pharmacokinetic studies in healthy humans for colonic delivery. The optimized formulation showed negligible drug release (4.33 ± 0.06 %) in the initial lag period followed by progressive release (100.78 ± 0.64 %) for 24 h. The X-ray imaging in human volunteers showed that the tablets reached the colon without disintegrating in the upper gastrointestinal tract. The C max of colon-targeted tablets was 12,374.67 ng/ml at T max 10 h, where as in case of immediate release tablets the C max was 15,677.52 ng/ml at T max 3 h, that signifies the ability of compression-coated tablets to target the colon. Development of compression-coated tablets using combination of time-dependent and pH-sensitive approaches was suitable to target the flurbiprofen to colon.

Proliposome powders for enhanced intestinal absorption and bioavailability of raloxifene hydrochloride: effect of surface charge

The primary goal of the present study was to investigate the combined prospective of proliposomes and surface charge for the improved oral delivery of raloxifene hydrochloride (RXH). Keeping this objective, the present systematic study was focused to formulate proliposomes by varying the ratio of hydrogenated soyphosphatidylcholine and cholesterol. Furthermore, to assess the role of surface charge on improved absorption of RXH, anionic and cationic vesicles were prepared using dicetyl phosphate and stearylamine, respectively. The formulations were characterized for size, zeta potential and entrapment efficiency. The improved dissolution characteristics assessed from dissolution efficiency, mean dissolution rate were higher for proliposome formulations. The solid state characterization studies indicate the transformation of native crystalline form of the drug to amorphous and/or molecular state. The higher effective permeability coefficient and fraction absorbed in humans extrapolated from in situ single-pass intestinal absorption study data in rats provide an insight on the potential of proliposomes and cationic surface charge for augment in absorption across gastro intestinal barrier. To draw the conclusions, in vivo pharmacokinetic study carried out in rats indicate a threefold enhancement in the rate and extent of absorption of RXH from cationic proliposome formulation which unfurl the potential of proliposomes and role of cationic charge for improved oral delivery of RXH.

Preparation and evaluation of mucoadhesive cefdinir microcapsules

The mucoadhesive microcapsules were prepared by using various concentrations of three different mucoadhesive polymers, namely, chitosan, Carbopol 934P, and methyl cellulose as wall materials and cefdinir as the core material employing orificeionic gelation method. The prepared microcapsules were characterized by scanning electron microscope (SEM) and Fourier transform infrared spectrometry (FT-IR). The prepared microcapsules were found to be spherical with particle size ranging from 765±20 to 985±10 μm and encapsulation efficiencies in the range of 55%-92%. The formulation containing Carbopol 934P as mucoadhesive polymer was found to be best with particle size 946±10 μm. The ex vivo wash-off test showed that the mucoadhesion after 1 h was 80% and the in vitro drug release was extended for more than 12 h. FT-IR spectra indicate that there was no interaction between drug and the polymers used in the formulation. Cefdinir is better absorbed from the upper part of the gastrointestinal tract, it suffers from low oral bioavailability (20-30%), shorter biological half-life (1-2 h), and less transit time. Thus, it can be concluded that microcapsules prepared using Carbopol 934P have promising properties for use as mucoadhesive carrier to increase the residence time of cefdinir.

Enhanced oral bioavailability of isradipine via proniosomal systems

The objective of the present research was to develop a proniosomal formulation of isradipine and to evaluate the influence of proniosomal systems on the oral bioavailability of the drug in albino Wistar rats. Proniosomes were prepared by film deposition on carrier's method using various molar ratios of nonionic surfactants such as span20, span40, span60, and span80 with cholesterol as membrane stabilizing agent and dicetylphosphate as a charge inducer. The formation of niosomes and surface morphology of proniosome formulations were studied by optical and scanning electron microscopy (SEM), respectively. The prepared proniosomes have shown higher dissolution of isradipine compared with pure drug powder. Fourier transform infrared spectroscopy, differential scanning calorimetry, and powder X-ray diffractometry studies were performed to understand the solid state properties of the drug. Ex vivo permeation enhancement assessed from flux, permeability coefficient, and enhancement ratio were significantly higher for proniosomes compared with control. The pharmacokinetic parameters were evaluated in male albino Wistar rats and a significant enhancement in the bioavailability (2.3-fold) was observed from optimized proniosome formulation compared with control (oral suspension). The stability study reveals that the proniosome formulations are stable when stored at 4°C.

Formulation, evaluation, and pharmacokinetics of isradipine proliposomes for oral delivery

Proliposomes loaded with isradipine were prepared successfully to enhance the oral bioavailability of isradipine. In this study, proliposomes were prepared by film deposition by the carrier method with varying ratios of hydrogenated soy phosphatidyl choline (HSPC) and cholesterol using spray-dried mannitol (Pearlitol SD 200) as the carrier. The formulation containing an equimolar ratio of HSPC and cholesterol showed smaller vesicle size, high surface charge, and entrapment efficiency. The formation of liposomes and surface morphology of optimized proliposome formulation was studied by optical and scanning electron microscopy, respectively. Fourier transform infrared, differential scanning calorimetry, and powder X-ray diffractometry studies were performed to assess the solid-state characteristics of the formulation. Ex vivo permeation enhancement assessed from flux, permeability coefficient, and enhancement ratio were significantly higher for proliposomes, compared to control. The pharmacokinetic parameters were evaluated in male albino Wistar rats, and a significant improvement in bioavailability (2.4-fold) was observed from the optimized proliposome formulation, compared to control (oral suspension). The stability study revealed that the formulations are stable when stored at 4°C.

Formulation and evaluation of buccoadhesive quetiapine fumarate tablets

The aim of present study was to develop and evaluate buccoadhesive Quetiapine Fumarate (QF) tablets, which is extensively metabolised by liver. Buccoadhesive tablets of QF were prepared using HPMC K4M, HPMC K15M and combination of carbopol and HPC as mucoadhesive polymers by direct compression method. Sodium deoxycholate was added to formulation to improve the permeation of drug. The formulations were tested for bioadhesion strength, ex vivo residence time, swelling time and in vitro dissolution studies and ex vivo permeation studies. Optimized formulation (F3) showed 92% in vitro release in 8 h and 67% permeation of drug through porcine buccal mucosa and followed fickian release mechanism with zero order kinetics. FTIR studies of optimized formulation showed no evidence of interaction between the drug and polymers. In vivo mucoadhesive behaviour of optimized formulation was performed and subjective parameters were evaluated.

Methoxy VO-salen stimulates pancreatic β cell survival by upregulation of eNOS and downregulation of apoptosis in STZ-induced diabetic rats

The present study was designed to investigate the effect of MetVO-salen in ameliorating diabetes and oxidative stress in the pancreas of diabetic rats. Streptozotocin (STZ)-induced diabetic rats were treated with MetVO-salen complex intraperitonially (0.3 and 0.6 mg/kg) thrice a week and continued for 8 weeks. Total cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides in serum, and blood glucose were estimated. Furthermore, oxidative stress in rats was also investigated in terms of superoxide dismutase (SOD), catalase, lipid peroxidation, and glutathione (GSH). In addition, the anti-diabetic activity of MetVO-salen was also investigated by assessing histopathological, immunohistochemical in terms of endothelial nitric oxide synthase expression, and apoptotic events in pancreas. Treatment with MetVO-salen complex reduced the blood glucose level and significantly altered the serum biochemical parameters of diabetic rats. Treatment with above complex decreased the lipid peroxidation and the antioxidant enzymes such as SOD, CAT, and GSH to near-control levels. Histopathological, immunohistochemical, and apoptotic studies also revealed that MetVO-salen-induced amelioration of the diabetic state appears to be significant to the preservation of a functional portion of the pancreatic β cells which initially prevent STZ toxicity. This study provides new direction for the management of diabetes but needs further clinical evaluation.

Oxidative stress induced by fluoroquinolones on treatment for complicated urinary tract infections in Indian patients

The aim of the study is to examine the oxidative stress in patients on fluoroquinolones (ciprofloxacin, levofloxacin, gatifloxacin) therapy for complicated urinary tract infections and to correlate with plasma concentrations at different time intervals. Superoxide dismutase (SOD), glutathione, plasma antioxidant status and lipid peroxides were evaluated in 52 patients on different dosage regimens up to 5 days. There is significant and gradual elevation of lipid peroxide levels in patients on ciprofloxacin (3.6 ± 0.34 nmol/ml to 6.2 ± 0.94 nmol/ml) and levofloxacin (3.5 ± 0.84 nmol/ml to 5.1 ± 0.28 nmol/ml) dosage regimen but not with gatifloxacin (3.5 ± 0.84 nmol/ml to 3.74 ± 0.17 nmol.ml). There was substantial depletion in both SOD and glutathione levels particularly with ciprofloxacin. On the 5(th) day of treatment, plasma antioxidant status decreased by 77.6% %, 50.5%, 7.56% for ciprofloxacin, levofloxacin and gatifloxacin respectively. In conclusion ciprofloxacin and levofloxacin induce more reactive oxygen species that lead to cell damage than gatifloxacin irrespective of their concentrations in patient population.

Downregulation of apoptosis and modulation of TGF-β1 by sodium selenate prevents streptozotocin-induced diabetic rat renal impairment

To investigate whether sodium selenate treatment would impact on the onset of diabetic nephropathy, we examined blood glucose, serum biochemical components, and interrelationship between oxidative stress, TGF-β1, and apoptosis in streptozotocin (STZ) induced diabetic rats. Sixty male Wistar rats were divided into six groups. Group I (n = 10), normal control; Group II (n = 10), diabetic control; Group III (n = 10), sodium selenate (16 μmoles/kg) + diabetic; Group IV (n = 10), sodium selenate (32 μmoles/kg) + diabetic; Group V (n = 10), sodium selenate (16 μmoles/kg) control; and Group VI (n = 10), sodium selenate (32 μmoles/kg) control. Sodium selenate was administered via orogastric route for 10 weeks. In the diabetic group, diabetes was induced by single intraperitoneal injection of STZ (50 mg/kg). The levels of blood glucose were estimated and total cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, creatinine, urea, and albumin were detected in serum. Antioxidant status was examined by measuring the superoxide dismutase (SOD), catalase, glutathione, and lipid peroxidation in kidney tissues. Histopathological studies were performed in the kidney tissue sections. The expression of TGF-β1 was estimated by the immunohistochemical analysis in kidneys. Apoptotic study in kidney was performed using the TdT-mediated dUTP nick end labeling technique. It was observed that blood glucose, serum, total cholesterol, HDL cholesterol, triglycerides, creatinine, urea, and albumin were significantly higher in diabetic control groups. Diabetic + sodium selenate (16 and 32 μmoles/kg) significantly reduced blood glucose, serum, total cholesterol, HDL cholesterol, triglycerides, creatinine, urea, and albumin levels. Selenium-treated groups significantly increased antioxidant enzyme activities (SOD, catalase, and glutathione) in kidneys of diabetic rats. All enzyme activities of selenium control groups did not differ compared with the normal control. Sodium selenate reduces significantly lipid peroxidation in diabetic rats. Cellular architecture of the diabetic rats was altered whereas sodium selenate administration rectifies the degenerative changes of the kidney. Profound immunopositivity of TGF-β1 was observed in the glomerular and tubulointerstitial cells of diabetic rat kidney. Immunopositivity of TGF-β1 was significantly reduced in both low and high dose of sodium-selenate-treated rats (P < 0.05, P < 0.01). High numbers of apoptotic cells were observed in diabetic rats whereas sodium selenate in both doses significantly reduces the incidence of apoptosis (P < 0.05, P < 0.01). We conclude herein that sodium selenate has the potential to play a significant role in limiting the renal impairment by altering the apoptosis and TGF-β1 in experimental diabetic rats.

Formulation and evaluation of taste-masked levocetirizine dihydrochloride orally disintegrating tablets

Orally disintegrating tablets of levocetirizine dihydrochloride were formulated with different superdisintegrants (sodium starch glycollate, croscarmellose sodium, and crospovidone) using mannitol as a diluent. Tulsion-335, Indion-204, and poly kyron T-134 cation exchange resins were used as taste-masking agents. The drug and resin complex was prepared by the kneading method. Ten formulations were prepared with varying combinations of superdisintegrants and ion-exchange resins by the wet granulation technique, using polyvinylpyrrolidone K-30 as the binder. The prepared tablets were evaluated for degree of taste masking, weight variation, hardness, friability, in vitro and in vivo disintegration time, content uniformity, and water absorption ratio. Dissolution studies were performed in two dissolution media: 0.1N HCl and distilled water. The corresponding dissolution rates were compared with the marketed formulation. Differential scanning calorimetry studies were carried out on the drug-resin complexes. Prepared tablets were good in appearance and showed acceptable results for hardness and friability. In vitro and in vivo disintegration times for the optimum formulation (F-1) were found to be 22 and 55 s, respectively. Relatively acceptable taste was achieved with both Indion-204 and Tulsion-335. Rapid disintegration time was achieved in tablets containing crosspovidone as the superdisintegrant. Dissolution studies indicated the formation of the complex of drug and resin. Differential scanning calorimetry studies indicated the formation of drug-resin complex.

Formulation and evaluation of bioadhesive buccal drug delivery of tizanidine hydrochloride tablets

The study aim was concerned with formulation and evaluation of bioadhesive buccal drug delivery of tizanidine hydrochloride tablets, which is extensively metabolized by liver. The tablets were prepared by direct compression using bioadhesive polymers such as hydroxylpropyl methylcellulose K4M, sodium carboxymethyl cellulose alone, and a combination of these two polymers. In order to improve the permeation of drug, different permeation enhancers like beta-cyclodextrin (beta-CD), hydroxylpropyl beta-cyclodextrin (HP-beta-CD), and sodium deoxycholate (SDC) were added to the formulations. The beta-CD and HP-beta-CD were taken in 1:1 molar ratio to drug in formulations. Bioadhesion strength, ex vivo residence time, swelling, and in vitro dissolution studies and ex vivo permeation studies were performed. In vitro release of optimized bioadhesive buccal tablet was found to be non-Fickian. SDC was taken in 1%, 2%, and 3% w/w of the total tablet weight. Stability studies in natural saliva indicated that optimized formulation has good stability in human saliva. In vivo mucoadhesive behavior of optimized formulation was performed in five healthy male human volunteers and subjective parameters were evaluated.

Antileishmanial activity, pharmacokinetics and tissue distribution studies of mannose-grafted amphotericin B lipid nanospheres

Leishmania parasite resides mainly in the liver and the spleen and multiplies. Effective therapy of leishmaniasis could be achieved by delivering antileishmanial drugs to these sites. Present investigations were aimed at developing lipid nanospheres of amphotericin B (LN-A) anchored with mannose to achieve targeted delivery to the liver. Mannose is specifically involved in the recognition of parasite or appropriate ligands on the macrophage surface LN-A, and mannose-anchored lipid nanospheres (LN-A-MAN) were prepared by homogenization followed by ultrasonication method. Particle size and zeta potential were measured using Malvern Zetasizer. The average particle size after sterilization of LN-A and LN-A-MAN ranged from 193.4 +/- 1.1 to 775.8 +/- 9.1. Leishmaniasis was induced in BALB/c mice by injecting Leishmania donovani parasites intravenously. Infected mice were administered with a single dose (5 mg/kg body weight) of LN-A, LN-A-MAN, and Fungizone (marketed product).The efficacy of the formulations was evaluated by measuring the reduction in parasite burden. Fungizone reduced 82 and 69%, LN-A reduced 90 and 85%, LN-A-MAN reduced 95 and 94% of parasite burden in the liver and the spleen, respectively. LN-A and LN-A-MAN-treated mice did not show any elevation in serum glutamate pyruvate transaminase (SGPT), alkaline phosphatase (ALP), urea, and creatinine levels as compared with Fungizone. Pharmacokinetic parameters were estimated and the concentration of amphotericin B (AmB) in mice plasma declined biexponentially and AmB concentrations were significantly higher for LN-A- and LN-A-MAN than Fungizone-treated mice (P < 0.05). Tissue distribution patterns were studied in different tissues such as the liver, the spleen, the kidney, and the brain of BALB/c mice. LN-A-MAN was found to distribute more rapidly to the liver and the spleen explaining the reason for higher antileishmanial activity.

Formulation and evaluation of swellable and floating gastroretentive ciprofloxacin hydrochloride tablets

Drugs that have narrow absorption window in the gastrointestinal tract (GIT) will have poor absorption. For these drugs, gastroretentive drug delivery systems offer the advantage in prolonging the gastric emptying time. Swellable, floating, and sustained release tablets are developed by using a combination of hydrophilic polymer (hydroxypropyl methylcellulose), swelling agents (crospovidone, sodium starch glycolate, and croscarmelose sodium) and effervescent substance (sodium bicarbonate). Formulations are evaluated for percentage swelling, in vitro drug release, floating lag time, total duration of floating, and mean residence time (MRT) in the stomach. The drug release of optimized formulation follows the Higuchi kinetic model, and the mechanism is found to be non-Fickian/anomalous according to Krosmeyer-Peppas (n value is 0.68). The similarity factor (f (2)) is found to be 26.17 for the optimized formulation, which the release is not similar to that of marketed produced (CIFRAN OD). In vivo nature of the tablet at different time intervals is observed in the radiographic pictures of the healthy volunteers and MRT in the stomach is found to be 320 +/- 48.99 min (n = 6). A combination of HPMC K100M, crospovidone, and sodium carbonate shows the good swelling, drug release, and floating characters than the CIFRAN OD.

Pharmacokinetics and tissue distribution of piperine lipid nanospheres

The purpose of this study was to estimate the pharmacokinetic parameters and tissue distribution of positively charged stearylamine (LN-P-SA) and pegylated lipid nanospheres (LN-P-PEG) of piperine in BALB/c mice. Lipid nanospheres of piperine (LN-P), LN-P-PEG and LN-P-SA were prepared by homogenization followed by ultrasonication. The pharmacokinetics and tissue distribution of different lipid nanosphere formulations (piperine, LN-P, LN-P-PEG and LN-P-SA) were studied in male BALB/c mice. The pharmacokinetic parameters of LN-P-PEG and LN-P-SA were: AUC(0-24): 372.1 +/- 71.6 and 162.2 +/- 36.4 microg h(-1) ml(-1), clearance 13 +/- 2.5 and 32 +/- 7.5 ml h(-1), Cmax: 24.7 +/- 1.5 and 22.3 +/- 1.0 microg ml(-1), Vd: 0.45 +/- 0.02 and 0.66 +/- 0.06 l Kg(-1)). Pharmacokinetics of piperine in lipid nanospheres showed a biexponential decline with significantly high AUC, a lower rate of clearance and a smaller volume of distribution than piperine.

Formulation and evaluation of gastroretentive dosage forms of Clarithromycin

The purpose of this research was to develop the hydrodynamically balanced delivery system of Clarithromycin (CLA) which, after oral administration should have the ability to prolong gastric residence time with the desired in vitro release profile for the localized action in the stomach, in the treatment of Helicobacter pylori (H.pylori) mediated peptic ulcer. By applying wet granulation technique floating tablets of Clarithromycin were prepared. The proportion of sodium bicarbonate was varied to get the least possible lag time, also the polymer part varied to get the desired release. In vivo radiographic studies were performed with Barium sulphate loaded formulation to justify the increased gastric residence time of the dosage form in the stomach, based on the floating principle. The formulation developed using 66.2% Clarithromycin, 12% HPMC K4M polymer, 8% sodium bicarbonate gave floating lag time less than 3 min with a floating time of 12 h, and an in vitro release profile very near to the desired release. X-ray studies showed the enhanced gastric residence time of the tablet to 220 +/- 30 min. The mechanism of release of Clarithromycin from the floating tablets is anomalous diffusion transport and follows zero order kinetics. In vivo radiographic studies suggest that the tablet has increased gastric residence time for the effective localized action of the antibiotic (Clarithromycin) in the treatment of H.pylori mediated peptic ulcer.

Formulation and evaluation of oil-in-water emulsions of piperine in visceral leishmaniasis

Present studies are aimed to find out the utility of oil-in-water emulsions also known as lipid nanospheres (LN) or fat emulsions for delivering piperine for the treatment of visceral leishmaniasis. Lipid nanosphere formulations of piperine were prepared using soybean oil, egg lecithin, cholesterol, stearylamine and phosphatidylethanolamine distearylmethoxypolyethyleneglycol (DSPE-PEG) by homogenization followed by ultrasonication of oil and aqueous phases. Antileishmanial activity of all the formulations was assessed in BALB/c mice infected with Leishmania donovani AG83 for 60 days. A single dose (5 mg/kg) of piperine, or lipid nanospheres of piperine (LN-P), or lipid nanosphere of piperine with stearylamine (LN-P-SA) or pegylated lipid nanospheres of piperine (LN-P-PEG) was injected intravenously. Mice were sacrificed after 15 days of treatment with piperine or formulations and Leishman Donovan Unit (LDU) is counted. Toxicity of formulations and pure piperine was assessed in normal mice. The size distribution of formulations ranged from 200 to 885 nm. Piperine reduced the parasite burden in liver and spleen by 38% and 31% after 15 days post infection respectively. LN-P reduced the parasite burden in liver and spleen by 63% and 52% after 15 days post infection, respectively. LN-P-PEG reduced the parasite burden in liver and spleen by 78% and 75% after 15 days post infection, respectively. LN-P-SA reduced the parasite burden in liver and spleen by 90% and 85% after 15 days post infection, respectively. LN-P, LN-P-PEG, LN-P-SA treated mice did not show any significant changes in the serum levels of SGOT, ALP, creatinine and urea compared to normal mice. Stable and sterile formulations of lipid nanospheres of piperine were developed. A single dose of 5 mg/kg of lipid nanospheres of piperine could significantly reduce the liver and splenic parasite burden.

Formulation and Evaluation of Gastroretentive Dosage Form of Ofloxacin

The aim of the present investigation was to develop and evaluate gastroretentive drug delivery tablets (GRDDTs) of ofloxacin using different polymers such as HPMC K4M, HPMC K15M, Polyethylene oxide WSR 303, Carbopol 971P, Xanthan Gum in different ratios for local action in gastric region to eradicate Helicobacter pylori infection. The GRDDTs were prepared by wet granulation method and evaluated for physical characteristics such as hardness, thickness, friability, drug content and floating properties. The optimized formula F4 showed better sustained drug release and which also had good floating properties and fitted best to be Korsmeyer-Peppas model with R2 value of 0.9848. As the n value for the Korsmeyer- Peppas model was found be less than 0.45 it follows Fickian diffusion mechanism. FT-IR result showed that there is no drug excipient interaction. In vivo radiographic studies were conducted with BaSO4 loaded tablets to examine the increased gastric residence time of the prepared tablets. The study revealed that the tablet remained in the stomach for 300±10min which indicates the increase in the gastric residence time for the effective localized action of the ofloxacin in the treatment of Helicobacter pylori caused peptic ulcer.   Key words: Ofloxacin; Helicobacter pylori; gastric residence time; gastroretentive drug delivery system.DOI: http://dx.doi.org/10.3329/sjps.v4i1.8861SJPS 2011; 4(1): 9-18