Optimization and Designing of Amikacin-loaded Poly D, L-Lactide-co-glycolide Nanoparticles for Effective and Sustained Drug Delivery.

PURPOSE: Amikacin, a water-soluble aminoglycoside antibiotic used to treat gram-negative bacillary infections, is a Biopharmaceutics Classification System class III drug having poor permeability and short half-life. It is given parenterally, which limits its use in patients warranting "at-home care." An oral drug delivery of amikacin is, therefore, imminent. AIM: This work focused on establishing poly d, l-lactide-co-glycolide (PLGA)-based nanoparticles of amikacin with consolidated pharmaceutical attributes capable of circumventing gastrointestinal tract membrane barriers and promoting oral administration of the drug. The partied attributes are suggestive of enhanced uptake of the drug via Peyer's patches overlaying small intestine and support successful oral delivery. MATERIALS AND METHODS: To have a robust delivery system, a statistical Box-Behnken experimental design was used and formulation parameters such as homogenization time, probe sonication time, and drug/polymer ratio of amikacin-loaded PLGA nanoparticles (A-NPs) for obtaining monodispersed nanoparticles of adequate size and high drug loading were optimized. RESULTS: The model suggested to use the optimum homogenization time, probe sonication time, and drug/polymer ratio as 30 s, 120 s, and 1:10, respectively. Under these formulation conditions, the particle size was found to be 260.3 nm and the drug loading was 3.645%. CONCLUSION: Biodegradable PLGA nanoparticulate systems with high payload, optimum size, and low polydispersity index will ensure successful uptake and ultimately leading to better bioavailability. Hence, under the aforementioned optimized conditions, the A-NPs prepared had particle size of 260.3 nm, which is appreciable for its permeability across small intestine, and drug loading of 3.645%.

Formulation development and evaluation of nifedipine as pylorospasm inhibitor.

INTRODUCTION: In this study, different nifedipine-loaded formulations were prepared to treat pylorospasm, a sphincter muscle disorder characterized by delayed gastric emptying process. The efficacy of formulation was evaluated in patients by subjective assessment, gamma scintigraphic approaches, and confocal microscopy. METHODS: Nifedipine-loaded different formulations such as sucrose bead, pellets, and microparticles (slugging method, ionotropic gelation, and chemical denaturation) were designed. The studies were performed on 50 subjects, of which 30 subjects were treated with optimized nifedipine loaded microcapsules while 20 subjects were given capsule becosule-Z as a control. The efficacy of formulation was assessed by comparing symptoms like dyspepsia, abdominal pain, abdominal fullness, poor appetite, nausea, vomiting, and irregular motion. The effectiveness of formulation was also assessed by gamma scintigraphic studies by determining the rate of emptying of a radioactivity labeled standard meal from patients' stomach into the duodenum. Confocal microscopy was used to assess targeting potential of developed formulation. RESULTS: Drug-loaded alginate-chitosan microcapsules were found to be satisfactory, in terms of controlled drug release, surface morphology, and bioadhesive properties and thus selected for in vivo studies. Clinical studies revealed the efficacy of formulation in abolishing various GI symptoms at high altitude. Associated symptoms such as dyspepsia, abdominal pain, poor appetite, nausea, vomiting, and irregular motion were recovered by 75, 62, 76.5, 86.7, 85.7, and 37.5%, respectively in nifedipine-treated patients. In comparison, 73.7, 40, 33.3, 40, 20, and 0% recoveries were observed in patients given control treatment only. Gamma Scintigraphic studies in lab also revealed 2.425 ± 0.245 (p < .05) times improvement in gastric emptying rate in patients with diabetic gastroparesis. Confocal analysis showed better targeting and penetration in pyloric region when formulation was administered in form of high-density microcapsules. CONCLUSIONS: Results strongly suggest that nifedipine loaded mucoadhesive formulation has a targeting potential which accelerates gastric emptying process in gastroparesis patients, and thus the formulation might prove useful as a potent prokinetic agent.

Alpha ketoglutarate nanoparticles: A potentially effective treatment for cyanide poisoning.

The purpose of this research work was to prepare nanosized formulation of alpha ketoglutarate as dry powder inhaler for cyanide poisoning. Nanosizing can be approached by solid phase and liquid phase method. The different conditions encountered in both these approaches can greatly affect the particle characteristics. In this study milling and precipitation technique were compared to study their effect on α-KG particles characteristics. Differences in choice of stabilizers were observed between the two processing techniques. Sonication processes followed by HPH produced small sized particles in which Pluronic F68 was employed as stabilizing agent. Precipitation approach produced ultrafine drug particles by utilizing combination of stabilizers (PVA+PEG 400). Amongst the two sonication processes, probe sonication process produced well stabilized small sized particles. The designed particles showed 43.13±2.36% lung deposition when compared with ultrasonication and precipitation technique that showed 31.69% and 21.67% respirable fraction. The MMAD of the designed particles was found suitable for deep alveolar deposition. Clinical studies (Phase-I trial) showed whole lung deposition of 52.51% for DPI. The P/C ratio was found to be 1.02 suggesting uniform distribution of particles in different lung compartments.

Changing Face of Wood Science in Modern Era: Contribution of Nanotechnology.

BACKGROUND: Wood science and nanomaterials science interact together in two different aspects; a) fabrication of lignocellulosic nanomaterials derived from wood and plant-based sources and b) surface or bulk wood modification by nanoparticles. In this review, we attempt to visualize the impact of nanoparticles on the wood coating and preservation treatments based on a thorough registration of the patent databases. METHOD: The study was carried out as an overview of the scientifically most followed trends on nanoparticles utilization in wood science and wood protection depicted by recent universal filed patents. This review is exclusively targeted on the solid (timber) wood as a subject material. RESULTS: Utilization of mainly metal nanoparticles as photoprotection, antibacterial, antifungal, antiabrasive and functional component on wood modification treatments was found to be widely patented. Additionally, an apparent minimization in the emission of volatile organic compounds (VOCs) has been succeeded. CONCLUSION: Bulk wood preservation and more importantly, wood coating, splay the range of strengthening wood dimensional stability and biological degradation, against moisture absorption and fungi respectively. Nanoparticle materials have addressed various issues of wood science in a more efficient and environmental way than the traditional methods. Nevertheless, abundant tests and regulations are still needed before industrializing or recycling these products.

Pulmonary delivery of nanosized alendronate for decorporation of inhaled heavy metals: formulation development, characterization and gamma scintigraphic evaluation.

CONTEXT: Medical management of heavy metal toxicity including radioactive ones is the cause of concern because of their increased use in energy production, healthcare and mining. As inhalation is one of the primary routes for internalization, a formulation is needed to trap metal(s) at the portal of entry itself. OBJECTIVE: Objective was to formulate and characterize a nanonized dry powder inhaler (DPI) formulation of alendronate sodium as potential inhalable antidote for chelating metal toxicants. METHODS: In vitro binding studies of alendronate with respect to seven non-radioactive heavy metals were carried out using UV-spectroscopy and HPLC. Nanonizing of alendronate particles was achieved by antisolvent precipitation using Pluronic-F68 as stabilizer. Characterization was done with the help of SEM, TEM FT-IR, XRD, DSC, NMR spectroscopy and PSD studies. In vitro and in vivo pulmonary deposition studies were carried out using gamma scintigraphy, followed by a limited pharmacokinetic study in humans. RESULTS: In vitro binding studies confirmed the chelating action of alendronate. Anderson cascade impaction showed that nano-alendronate exhibited significantly higher respirable fraction (58.25 ± 1.32%) compared to the micronized form (28.7 ± 0.59%). Scintigraphy results showed significant increase in the alveolar deposition of drug post-nanonizing. CONCLUSION: Results strongly indicate the role of nano-alendronate DPI as potential inhalable antidote for neutralizing heavy metal toxicity, including radio-metal contamination.

Inhalation of alendronate nanoparticles as dry powder inhaler for the treatment of osteoporosis.

The precipitation technique was used to prepare non-polymeric alendronate nanoparticles. The influence of various formulation parameters on the average particle size was investigated and the effect of various stabilizers (PVA, tween, chitosan, alginate, PEG, HPMC, poloxomers) was evaluated. The selection of surfactant was a key factor to produce particles with desired properties. Poloxomer F68 was found best in achieving the minimum particle size and providing physical stability to the drug. On basis of preliminary trials, a central composite design was employed to study the effect of independent variables, drug concentration (X1), antisolvent volume (X2), stirring speed (X3), and stabilizer concentration (X4) on the average particle size. The drug and stabilizer concentrations exhibited a more significant effect on a dependent variable. The particle size varied from 62 to 803.3 nm depending upon the significant terms. The validation of optimization study, performed using six confirmatory runs, indicated very high degree of prognostic ability of response surface methodology, with mean percentage error (±SD) as -2.32 ± 2.47. The minimum particle size (44.11 nm) was predicted at 10 mg/ml drug concentration, 20 ml antisolvent volume, 925 rpm stirring speed, and 8.5% stabilizer concentration with 98.16% experimental validity. Respirable fraction for optimized nanosized alendronate (43.85% ± 0.52%) was significantly higher when compared with commercial alendronate (17.6 ± 0.32). Mass median aerodynamic diameter of designed particles was 3.45 µm with geometric standard deviation of 2.10.

Development and evaluation of nanosized niosomal dispersion for oral delivery of Ganciclovir.

Encapsulation of Ganciclovir in lipophilic vesicular structure may be expected to enhance the oral absorption and prolong the existence of the drug in the systemic circulation. So the purpose of the present study was to improve the oral bioavailability of Ganciclovir by preparing nanosized niosomal dispersion. Niosomes were prepared from Span40, Span60, and Cholesterol in the molar ratio of 1:1, 2:1, 3:1, and 3:2 using reverse evaporation method. The developed niosomal dispersions were characterized for entrapment efficiency, size, shape, in vitro drug release, release kinetic study, and in vivo performance. Optimized formulation (NG8; Span60:Cholesterol 3:2 molar ratio) has shown a significantly high encapsulation of Ganciclovir (89±2.13%) with vesicle size of 144±3.47 nm (polydispersity index [PDI]=0.08). The in vitro release study signifies sustained release profile of niosomal dispersions. Release profile of prepared formulations have shown that more than 85.2±0.015% drug was released in 24 h with zero-order release kinetics. The results obtained also revealed that the types of surfactant and Cholesterol content ratio altered the entrapment efficiency, size, and drug release rate from niosomes. In vivo study on rats reveals five-time increment in bioavailability of Ganciclovir after oral administration of optimized formulation (NG8) as compared with tablet. The effective drug concentration (>0.69 µg/mL in plasma) was also maintained for at least 8 h on administration of the niosomal formulation. In conclusion, niosomes can be proposed as a potential oral delivery system for the effective delivery of Ganciclovir.

Enhanced bioavailability of nano-sized chitosan-atorvastatin conjugate after oral administration to rats.

A novel approach to improve the bioavailability and stability of atorvastatin (AT) was developed by constructing a nano-sized polymer-atorvastatin conjugate. Firstly, a novel chitosan-atorvastatin (CH-AT) conjugate was efficiently synthesized through amide coupling reaction. The formation of conjugate was confirmed by (1)H NMR and FT-IR spectrometry. Nano-sized conjugate with a mean size of 215.3±14.2 nm was prepared by the process of high pressure homogenization (HPH). Scanning electron microscopy (SEM) revealed that CH-AT nano-conjugate possess smooth surface whereas X-ray diffraction (XRD) spectra demonstrated amorphous nature of nano-conjugate. Further, CH-AT nano-conjugate showed solubility enhancement of nearly 4-fold and 100-fold compared to CH-AT conjugate and pure AT, respectively. In vitro drug release studies in simulated gastric fluid and simulated intestinal fluid suggested sustained release of AT from the conjugate. Additionally, the nano-conjugate significantly reduced the acidic degradation of AT. The plasma-concentration time profile of AT after oral administration of CH-AT nano-conjugate (2574±95.4 ng/mL) to rat exhibited nearly 5-fold increase in bioavailability compared with AT suspension (583±55.5 ng/mL). Finally, variable bioavailability, as observed for AT suspension was also reduced when AT was administered in form of CH-AT nano-conjugate. Taken together these data demonstrate that chitosan conjugate nano-prodrugs may be used as sustained polymeric prodrugs for enhancing bioavailability.

Microscopic and spectroscopic evaluation of novel PLGA-chitosan Nanoplexes as an ocular delivery system.

The interaction of PLGA-chitosan Nanoplexes with ocular mucosa was investigated ex vivo and in vivo to assess their potential as ocular delivery system. Fluorescent Rhodamine Nanoplexes (Rd-Nanoplexes) were prepared by ionotropic gelation method. The size and morphology of Nanoplexes was investigated by TEM, SEM and PCS. The corneal retention, uptake and penetration of Nanoplexes were analyzed by spectrofluorimetry and confocal microscopy. Corneas from Rd-Nanoplexes-treated rabbits were evaluated for the in vivo uptake and ocular tolerance. The Nanoplexes prepared were round with a mean diameter of 115.6±17nm and the encapsulation efficiency of Rd was 59.4±2.5%. Data from ex vivo and in vivo studies showed that the amounts of Rd in the cornea were significantly higher for Nanoplexes than for a control Rd solution, these amounts being fairly constant for up to 24h. Confocal microscopy of the corneas revealed paracellular and transcellular uptake of the Nanoplexes. The uptake mechanism postulated was adsorptive-mediated endocytosis and opening of the tight junctions between epithelial cells. No alteration was microscopically observed after ocular surface exposure to Nanoplexes. Taken together, these data demonstrate that Nanoplexes are potentially useful as ocular drug carriers.

A validated HPTLC method for determination of terbutaline sulfate in biological samples: Application to pharmacokinetic study.

Terbutaline sulfate (TBS) was assayed in biological samples by validated HPTLC method. Densitometric analysis of TBS was carried out at 366 nm on precoated TLC aluminum plates with silica gel 60F254 as a stationary phase and chloroform-methanol (9.0:1.0, v/v) as a mobile phase. TBS was well resolved at RF 0.34 ± 0.02. In all matrices, the calibration curve appeared linear (r (2) â©¾ 0.9943) in the tested range of 100-1000 ng spot(-1) with a limit of quantification of 18.35 ng spot(-1). Drug recovery from biological fluids averaged ⩾95.92%. In both matrices, rapid degradation of drug favored and the T 0.5 of drug ranged from 9.92 to 12.41 h at 4 °C and from 6.31 to 9.13 h at 20 °C. Frozen at -20 °C, this drug was stable for at least 2 months (without losses >10%). The maximum plasma concentration (Cpmax) was found to be 5875.03 ± 114 ng mL(-1), which is significantly higher than the maximum saliva concentration (Csmax, 1501.69 ± 96 ng mL(-1)). Therefore, the validated method could be used to carry out pharmacokinetic studies of the TBS from novel drug delivery systems.

Stability indicating HPTLC method for determination of terbutaline sulfate in bulk and from submicronized dry powder inhalers.

A stability-indicating high-performance thin-layer chromatographic (HPTLC) method has been developed for the determination of terbutaline sulfate (TBS) as a bulk drug and in pharmaceutical formulations (submicronized dry powder inhalers). The separation was achieved on TLC aluminum plates precoated with silica gel 60F-254 using chloroform-methanol (9.0:1.0 v/v) as mobile phase. The densitometric analysis was carried out at 366 nm wavelength. Compact spots appeared at R(f) = 0.34 +/- 0.02. For the proposed procedure, linearity (r(2) = 0.9956 +/- 0.0015), limit of quantification (28.35 ng spot(-1)), limit of detection (9.41 ng spot(-1)), recovery (97.06-99.56%), and precision (< or = 1.86) were found to be satisfactory. TBS was subjected to acid and alkali hydrolyses, oxidation and photodegradation treatments. The degraded products were well separated from the pure drug. Statistical analysis reveals that the developed method has potential for routine analysis and stability testing of terbutaline sulfate in pharmaceutical drug delivery systems.

Ultra high-pressure liquid chromatographic assay of moxifloxacin in rabbit aqueous humor after topical instillation of moxifloxacin nanoparticles.

The present report describes a rapid and sensitive ultra high-pressure liquid chromatography (UHPLC) method with UV detection to quantify moxifloxacin in rabbit aqueous humor. After deproteinisation with acetonitrile, gradient separation of moxifloxacin was achieved on a Waters Acquity BEH C18 (50mmx2.1mm, 1.7microm) column at 50 degrees C. The mobile phase consisted of 0.1% trifluoroacetic acid in water and acetonitrile at a flow rate of 0.4ml/min. Detection of moxifloxacin was done at 296nm. Method was found to be selective, linear (r=0.9997), accurate (recovery, 97.30-99.99%) and precise (RSD, t), 3.14microg h/ml) compared with Moxi-SOL (AUC(0-->t), 0.79microg h/ml) and Moxi-ANP (AUC(0-->t), 0.72microg h/ml) formulation. The results indicate that the cationic nanoparticle increases ocular bioavailability of moxifloxacin and prolong its residence time in the eye.

CNS drug delivery systems: novel approaches.

The brain is a delicate organ, and nature has very efficiently protected it. The brain is shielded against potentially toxic substances by the presence of two barrier systems: the blood brain barrier (BBB) and the blood cerebrospinal fluid barrier (BCSFB). Unfortunately, the same mechanisms that protect it against intrusive chemicals can also frustrate therapeutic interventions. Despite aggressive research, patients suffering from fatal and/or debilitating central nervous system (CNS) diseases, such as brain tumours, HIV encephalopathy, epilepsy, cerebrovascular diseases and neurodegenerative disorders, far outnumber those dying of all types of systemic cancers or heart diseases. The abysmally low number of potential therapeutics reaching commercial success is primarily due to the complexity of the CNS drug development. The clinical failure of many probable candidates is often, ascribable to poor delivery methods which do not pervade the unyielding BBB. It restricts the passive diffusion of many drugs into the brain and constitutes a significant obstacle in the pharmacological treatment of central nervous system (CNS) disorders. General methods that can enhance drug delivery to the brain are, therefore, of great pharmaceutical interest. Various strategies like non-invasive methods, including drug manipulation encompassing transformation into lipophilic analogues, prodrugs, chemical drug delivery, carrier-mediated drug delivery, receptor/vector mediated drug delivery and intranasal drug delivery, which exploits the olfactory and trigeminal neuronal pathways to deliver drugs to the brain, are widely used. On the other hand the invasive methods which primarily rely on disruption of the BBB integrity by osmotic or biochemical means, or direct intracranial drug delivery by intracerebroventricular, intracerebral or intrathecal administration after creating reversible openings in the head, are recognised. Extensive review pertaining specifically, to the patents relating to drug delivery across the CNS is currently available. However, many patents e.g. US63722506, US2002183683 etc., have been mentioned in a few articles. It is the objective of this article to expansively review drug delivery systems for CNS by discussing the recent patents available.

An HPTLC method for the determination of minocycline in human plasma, saliva, and gingival fluid after single step liquid extraction.

A rapid, sensitive and specific high-performance thin-layer chromatographic (HPTLC) method was developed and validated for determination of minocycline in human plasma, saliva, and gingival fluid samples. Densitometric analysis of minocycline was carried out at 345 nm after single step extraction with methanol. The method uses TLC aluminium plates pre-coated with silica gel 60F-254 as a stationary phase and methanol-acetonitrile-isopropyl alcohol-water (5:4:0.5:0.5, v/v/v/v) as mobile phase. In all the three matrices, the calibration curve was linear (r(2) >/= 0.9958) in the tested range of 100 - 1200 ng spot(-1) with a limit of quantification of 15.4 ng spot(-1). Drug recovery from plasma, saliva and gingival fluid averaged 97.7%. Intra- and inter-day accuracies, determined at three different concentrations, were 95.08 to 100.6% and the corresponding precision (% CV) values were < 4.61%. In all the three matrices, rapid degradation of drug occurred and the half-life of drug ranged from 9.9 to 16.1 h at 4 degrees C and from 6.3 to 11.5 h at 20 degrees C. Frozen at -20 degrees C, this drug was stable for at least 2 months and can tolerate two freeze-thaw cycles without losses higher than 10%. The method's ability to quantify minocycline with precision, accuracy and sensitivity makes it useful in pharmacokinetic studies.

Development and clinical trial of nano-atropine sulfate dry powder inhaler as a novel organophosphorous poisoning antidote.

The aim of the work was to develop, characterize, and carry out a clinical trial with nano-atropine sulfate (nano-AS) dry powder inhaler (DPI), because this route may offer several advantages over the conventional intramuscular route as an emergency treatment, including ease of administration and more rapid bioavailability. Different batches of nanoparticles of AS were produced using variants of nanoprecipitation method. The influence of the process parameters, such as the types and quantity of solvent and nonsolvent, the stirring speed, the solvent-to-nonsolvent volume ratio, and the drug concentration, was investigated. The methodology resulted in optimally sized particles. Bulk properties of the particles made by the chosen methodology were evaluated. A clinical trial was conducted in six healthy individuals using a single DPI capsule containing 6 mg nano-AS DPI in lactose. Early blood bioavailability and atropinization pattern confirmed its value as a potential replacement to parenteral atropine in field conditions. The formulation seems to have the advantage of early therapeutic drug concentration in blood due to absorption through the lungs as well as sustained action due to absorption from the gut of the remaining portion of the drug.

Buccoadhesive drug delivery systems--extensive review on recent patents.

Peroral administration of drugs, although most preferred by both clinicians and patients has several disadvantages such as hepatic first pass metabolism and enzymatic degradation within the GI tract, that prohibit oral administration of certain classes of drugs especially peptides and proteins. Consequently, other absorptive mucosae are considered as potential sites for administration of these drugs. Among the various transmucosal routes studied the buccal mucosa offers several advantages for controlled drug delivery for extended period of time. The mucosa is well supplied with both vascular and lymphatic drainage and first-pass metabolism in the liver and pre-systemic elimination in the gastrointestinal tract is avoided. The area is well suited for a retentive device and appears to be acceptable to the patient. With the right dosage form, design and formulation, the permeability and the local environment of the mucosa can be controlled and manipulated in order to accommodate drug permeation. Buccal drug delivery is thus a promising area for continued research with the aim of systemic and local delivery of orally inefficient drugs as well as feasible and attractive alternative for non-invasive delivery of potent protein and peptide drug molecules. Extensive review pertaining specifically to the patents relating to buccal drug delivery is currently available. However, many patents e.g. US patents 6, 585,997; US20030059376A1 etc. have been mentioned in few articles. It is the objective of this article to extensively review buccal drug delivery by discussing the recent patents available. Buccal dosage forms will also be reviewed with an emphasis on bioadhesive polymeric based delivery systems.

Chitosan-sodium alginate nanoparticles as submicroscopic reservoirs for ocular delivery: formulation, optimisation and in vitro characterisation.

Management of extraocular disease is mainly limited by the inability to provide long-term extraocular drug delivery without avoiding the systemic drug exposure and/or affecting the intraocular structures and poor availability of drugs, which may be overcome by prolonging the contact time with the ocular surface, for instance with bioadhesive polymers. In the present study, mucoadhesive chitosan (CS)-sodium alginate (ALG) nanoparticles were investigated as a new vehicle for the prolonged topical ophthalmic delivery of antibiotic, gatifloxacin. A modified coacervation or ionotropic gelation method was used to produce gatifloxacin-loaded submicroscopic nanoreservoir systems. It was optimised using design of experiments by employing a 3-factor, 3-level Box-Behnken statistical design. Independent variables studied were the amount of the bioadhesive polymers: CS, ALG and the amount of drug in the formulation. The dependent variables were the particle size, zetapotential, encapsulation efficiency and burst release. Response surface plots were drawn, statistical validity of the polynomials was established and optimised formulations were selected by feasibility and grid search. Nanoparticles were characterised by FT-IR, DSC, TEM and atomic force microscopy. Drug content, encapsulation efficiency and particle properties such as size, size distribution (polydispersity index) and zetapotential were determined. The designed nanoparticles have average particle size from 205 to 572 nm (polydispersity from 0.325 to 0.489) and zetapotential from 17.6 to 47.8 mV. Nanoparticles revealed a fast release during the first hour followed by a more gradual drug release during a 24-h period following a non-Fickian diffusion process. Box-Behnken experimental design thus facilitated the optimisation of mucoadhesive nanoparticulate carrier systems for prolonged ocular delivery of the drug.

Optimisation of polyherbal gels for vaginal drug delivery by Box-Behnken statistical design.

The present research work aimed at development and optimisation of mucoadhesive polyherbal gels (MPG) for vaginal drug delivery. As the rheological and mucoadhesive properties of the gels correlate well to each other the prepared MPGs were optimised for maximum mucoadhesion using a relationship between the storage modulus (G') and Gel Index (GI), by employing a 3-factor, 3-level Box-Behnken statistical design. Independent variables studied were the polymer concentration (X(1)), honey concentration (X(2)) and aerosil concentration (X(3)). Aerosil has been investigated for the first time to improve the consistency of gels. The dependent variables studied were the elastic modulus, G'(Y(1)), gel index (Y(2)), and maximum detachment force (Y(3)) with applied constraints of 500

Development and bioavailability assessment of ramipril nanoemulsion formulation.

The objective of our investigation was to design a thermodynamically stable and dilutable nanoemulsion formulation of Ramipril, with minimum surfactant concentration that could improve its solubility, stability and oral bioavailability. Formulations were taken from the o/w nanoemulsion region of phase diagrams, which were subjected to thermodynamic stability and dispersibility tests. The composition of optimized formulation was Sefsol 218 (20% w/w), Tween 80 (18% w/w), Carbitol (18% w/w) and standard buffer solution pH 5 (44% w/w) as oil, surfactant, cosurfactant and aqueous phase, respectively, containing 5 mg of ramipril showing drug release (95%), droplet size (80.9 nm), polydispersity (0.271), viscosity (10.68 cP), and infinite dilution capability. In vitro drug release of the nanoemulsion formulations was highly significant (p<0.01) as compared to marketed capsule formulation and drug suspension. The relative bioavailability of ramipril nanoemulsion to that of conventional capsule form was found to be 229.62% whereas to that of drug suspension was 539.49%. The present study revealed that ramipril nanoemulsion could be used as a liquid formulation for pediatric and geriatric patients and can be formulated as self-nanoemulsifying drug delivery system (SNEDDS) as a unit dosage form.