Global Pediatric Regulations: An Overview.

The purpose of the present review is to summarize the current pediatric regulatory requirements and also the regulatory efforts that need to be taken for the potential benefits of safety and efficacy to the pediatric patients. The importance of pediatric regulations came into existence as adult physiological conditions differ from that of children; therefore, the same dosage regimen cannot be recommended for both. Children deviate from adults with respect to pharmacokinetic and pharmacodynamic characteristics, and hence the effect of the drug has to be reconfirmed for pediatrics. Drugs used in pediatric clinics are often considered as "therapeutic orphans" throughout the world as they are difficult to develop and are not provided with sufficient information. The number of clinical trials performed in children is not sufficient. At present, laws and regulations aimed at drug development in the pediatric field have not been focused significantly. There are different regulatory bodies that administrate the pediatric regulations for a particular region.

Stimuli-responsive biodegradable polyurethane nano-constructs as a potential triggered drug delivery vehicle for cancer therapy.

Polyurethanes (PUs) constitute an essential class of stimuli-responsive and biodegradable material, which has significantly contributed to the advancement of polymers utilization in the biomedical field. The bio-erodible PUs construct an active corridor for facilitating drug into tumor cells, which has significantly impacted the progression of nano-micellar delivery systems. The self-assembledcolloidal PUs pose distinctive features such as enhancing the solubility of hydrophobic chemotherapeutics, rapid cellular uptake, triggered erosion and drug release, bio-stimulus sensitivity, improvement in the targeting and proficiency ofbioactive. Cationic PUs can easily be condensed with genetic material to form polyplexes and have shown excellent transfection efficiency for potential gene therapy against various cancers. Their modifiable chemistry offers a tool to impart the desired multifunctionality such as biocompatibility, sensitivity to pH, redox, temperature, enzyme, etc. and ligand conjugation for active targeting. These diverse exceptional properties make them excellent nano-carrier for a variety of bioactive, including chemotherapeutic drugs, DNA, RNA, and diagnostic moieties to the target tissue or cells. The PUs based nano-devices have certainly uncovered the path to achieve ideal systems for controlled personalized therapy. The literature discussed in this review shed light on the research innovations carried out in the last ten years for the development of multifunctional PUs for triggered delivery of bioactive to treat various cancers.

Global Pediatric Regulations: An Overview.

The purpose of the present review is to summarize the current pediatric regulatory requirements and also the regulatory efforts that need to be taken for the potential benefits of safety and efficacy to the pediatric patients. The importance of pediatric regulations came into existence as adult physiological conditions differ from that of children; therefore, the same dosage regimen cannot be recommended for both. Children deviate from adults with respect to pharmacokinetic and pharmacodynamic characteristics, and hence the effect of the drug has to be reconfirmed for pediatrics. Drugs used in pediatric clinics are often considered as "therapeutic orphans" throughout the world as they are difficult to develop and are not provided with sufficient information. The number of clinical trials performed in children is not sufficient. At present, laws and regulations aimed at drug development in the pediatric field have not been focused significantly. There are different regulatory bodies that administrate the pediatric regulations for a particular region.

Engineering of a hybrid polymer-lipid nanocarrier for the nasal delivery of tenofovir disoproxil fumarate: physicochemical, molecular, microstructural, and stability evaluation.

PURPOSE: To engineer a hybrid nanocarrier system based on lipid and polymer for the nasal delivery of tenofovir disoproxil fumarate (TDF), and further to investigate its physicochemical, molecular, microstructural, and stability aspects. METHODS: Nanoparticles were prepared by melt emulsification-probe sonication technique. A 3(2) factorial design was used to identify key formulation variables influencing the characteristics of drug-loaded carrier. FT-IR, mass spectroscopy (MS) and (1)H NMR was used to probe molecular interactions among the components of the system, while the surface morphology was imagined through electron microscopy (TEM and SEM). Thermal analysis and powder X-ray diffraction (PXRD) was used to explore melting and crystallization behavior of drug and the carrier lipid. PLN-9 GEL was studied for its rheology, drug release, ex-vivo permeation, histopathology, and stability. RESULTS: Batch PLN-9 had size of 239 nm, drug encapsulation of 87.14% and revealed spherical morphology. MS, FT-IR and (1)H NMR established compatibility between the drug (TDF) and the carrier lipid (Lauric acid), while, a strong H-bonding was identified between the amino (-NH2) group of drug and the carboxyl (-COOH) group of pemulen polymer. Thermal analysis confirmed an amorphous TDF within the carrier matrix. PXRD analysis indicated substantial change in the molecular packing and subcell structure of carrier lipid during the PLN processing. PLN-9 GEL had shear thinning rheology, an anomalous type (n>0.5) of drug release and possessed potential to transport TDF across the nasal mucosa with an average flux of 135.36 µg/cm(2)/h. CONCLUSION: The designed carrier can encapsulate TDF and accentuates its transnasal flux, thus could be used as a carrier for an effective nasal delivery of TDF.

Cellular interactions and photoprotective effects of idebenone-loaded nanostructured lipid carriers stabilized using PEG-free surfactant.

In past years, nanostructured lipid carriers (NLCs) have emerged as novel topical antioxidant delivery systems because of combined positive features of liposomes and polymeric nanoparticles. Here, we seek to unlock the possibility of idebenone (IDB; an antioxidant)-loaded NLCs (IDB-NLCs) cellular interactions such as, viability and uptake, and its photoprotective effects against Ultraviolet-B (UVB)-mediated oxidative stress in immortal human keratinocyte cell line (HaCaT). The two-step preformulation strategy followed by three-level, three-variable, L9 (3(3)) Taguchi robust orthogonal design employed was important in improving IDB-NLCs key physicochemical aspects such as, entrapment efficiency, drug release (sustained), occlusion, skin deposition and physical stability. UV crosslinker, confocal microscopy and flow cytometry techniques were used to (1) mediate oxidative stress in HaCaT cells, (2) study a qualitative cellular uptake, (3) measure intracellular reactive oxygen species (ROS), and mitochondrial membrane potential, respectively. NLCs markedly improved biocompatibility of IDB under normal as well as stress conditions. Quantitative and qualitative cell uptake studies demonstrated a significant uptake of IDB-NLCs (3-fold increase) and nile red-labeled IDB-NLCs (NR-IDB-NLCs) at 2 h, respectively, hence exerted improved photoprotective effects.

Skin delivery aspects of benzoyl peroxide-loaded solid lipid nanoparticles for acne treatment.

BACKGROUND: Benzoyl peroxide (BPO) has been a mainstay of topical acne treatment for years. However, is frequently accompanied by cutaneous irritation and erythema. To reduce these side effects many novel drug delivery systems have been developed in the past, of which solid lipid nanoparticles (SLN) demonstrate clear dominance. Hence, we developed a facile method to prepare stable SLN of BPO and evaluated their anti-bacterial activity. RESULTS: BPO-SLN optimized using 2(3) full factorial design provided high occlusion factor, low permeation rate, increased drug deposition, reduced skin irritation and strong anti-bacterial activity in contrast with marketed product. CONCLUSION: Desired goals were achieved by factorial design approach in shortest possible time with minimum number of experiments. The developed BPO-SLN system provided controlled drug release, thereby reducing the well-known side effects.

Structure function attributes of gold nanoparticle vaccine association: effect of particle size and association temperature.

Many biotherapeutic applications of gold nanoparticles make use of conjugated or adsorbed protein moieties. Physical parameters of association such as particle size, morphology, surface chemistry and temperature influences the protein-nanoparticle association and thereby their interaction with the biological environment. In present study, effect of size of chitosan reduced gold nanoparticles (CsAuNPs) and association temperature on structure and function of tetanus toxoid (TT) vaccine has been investigated. CsAuNPs were synthesized in the sizes of 20±3, 40±5 and 80±7 nm followed by loading of TT. Binding process of CsAuNPs with TT was investigated at their predetermined micro molar concentrations. Upon binding of TT onto CsAuNPs, particle surface was characterized using X-ray photoelectron spectroscopy. CD spectroscopic evaluation of TT bound 20 nm CsAuNPs led to 75% reduction in secondary structure of TT and thereby compromised immune function. Binding of TT with 40 and 80 nm sized CsAuNPs did not cause significant modifications in secondary structure or function of TT. Thermodynamic studies using temperature dependent fluorescence spectroscopy revealed an increase in association constants with the temperature. Based on thermodynamic data three phases in CsAuNPs and TT association process were traced. Samples from these distinct phases were also investigated for immunological recognition. Ex-vivo interaction of TT-CsAuNPs with TT positive and negative sera followed by relative change in particle size and zeta potential was studied. The findings here suggests prominent role of particle size and association temperature on adsorbed TT structure and function. Such studies may help in engineering functional nanotherapeutics.

Probing influence of methodological variation on active loading of acetazolamide into nanoliposomes: biophysical, in vitro, ex vivo, in vivo and rheological investigation.

In the present work comparative evaluation of acetate and pH gradient techniques for effective drug loading in liposomes has been investigated. The acetazolamide (ACZ) loaded liposomes prepared by two methods were analyzed by vesicle size analysis, zeta potential, percent encapsulation efficiency, in vitro drug release studies and intraocular pressure lowering activity. ICH guidelines were followed for determining stability of the prepared liposomes. The superiority of acetate gradient method for active loading of acetazolamide has been established. The prepared acetate gradient positive liposomes showed extended hypotensive effect when compared to other liposomal formulations. Thus ACZ loaded liposomes prepared by acetate gradient technique may serve as promising ocular delivery system in the treatment of glaucoma. The current work emphasizes the fact that the techniques used for active drug loading into liposomes strongly influence the pharmaceutical performance of the final formulation.

Rifapentine-proliposomes for inhalation: in vitro and in vivo toxicity.

BACKGROUND: Oral therapy for pulmonary tuberculosis (TB) treatment suffers from the limitation of hepatic metabolism leading insufficient concentration of antitubercular (anti-TB) drugs in alveolar macrophage which harbors Mycobacterium tuberculosis (MTB). Targeted aerosol delivery of antituberculous drug to lung is efficient for treating local lung TB infection. OBJECTIVE: The present study was aimed to evaluate rifapentine (RPT) loaded proliposomal dry powder for inhalation (RLDPI) for anti-TBactivity and cytotoxicity in vitro. In vivo toxicity study was also undertaken in Wistar rats to determine safe concentration of RLDPI for administration. MATERIALS AND METHODS: Anti-TB activity of developed RLDPI was assessed using drug susceptibility testing (DST) on Mycobacteria growth indicator tube (MGIT) method. In vitro cytotoxicity was performed in A549 cell lines and IC50 values were used to compare the cytotoxicity of formulation with pure RPT. In vivo repeated dose toxicity study was undertaken using Wistar rats at three different doses for 28-days by intratracheal insufflations method. RESULTS: The results of DST study revealed sensitivity of tubercle bacteria to RLDPI at concentration equivalent to 10 µg/mL of RPT. This study confirmed anti-TB potential of RPT in spray-dried RLDPI, though the spray drying method is reported to reduce activity of drugs. Cytotoxicity study in A549 cells demonstrated that RPT when encapsulated in liposomes as RLDPI was safe to cells as compared to pure RPT. In vivo toxicity study revealed that RPT in the form of RLDPI was safe at 1 and 5 mg/kg dose. However, mortality was seen at higher dose (10 mg/kg), possibly because of liver and kidney damage. CONCLUSION: Thus, these studies demonstrated safety of RLDPI for the treatment of pulmonary TB.

Rheological investigation and its correlation with permeability coefficient of drug loaded carbopol gel: influence of absorption enhancers.

CONTEXT: The present study was planned to investigate the effect of absorption enhancers on the microstructure of Losartan potassium gel and hence its influence on the diffusion of Losartan potassium across nasal mucosa. METHOD: Losartan potassium loaded carbopol gel (1% w/v) with and without absorption enhancers was prepared. Polyethylene glycol (PEG) 4000 and ethanol were used as absorption enhancers. Microstructural elucidation of prepared gels was done using shear rheology. Ex vivo drug release studies were performed on the prepared gels. RESULTS: It was observed that the absorption enhancers PEG 4000 and ethanol altered the gel microstructure. The prepared gels were viscoelastic in nature suggesting their suitability for topical application. Permeability coefficient of Losartan potassium loaded into gels was found to be inversely proportional to the storage modulus. Thus increase in storage modulus lead to slow drug diffusion. CONCLUSION: The current study emphasizes on the fact that selection of polymeric carrier for nasal drug delivery and/or absorption enhancer strongly influence the microstructure of the gel and hence the pharmaceutical performance of the formulation.

Bicalutamide nanocrystals with improved oral bioavailability: in vitro and in vivo evaluation.

CONTEXT: Bicalutamide (BCT) is an antiandrogenic compound belonging to Biopharmaceutics Classification System (BCS) class II drug. Thus it has limited aqueous solubility and hence limited oral bioavailability. OBJECTIVE: The purpose of the present investigation was to obtain stable nanocrystals of BCT with improved kinetic solubility, dissolution and pharmacokinetic profiling. MATERIALS AND METHODS: BCT nanocrystals were prepared by antisolvent precipitation method using Soluplus, a novel amphiphilic polymer. Nanocrystals were characterized for particle size, powder X-ray diffraction analysis (PXRD), in vitro dissolution, in vivo pharmacokinetic profile and stability. RESULTS AND DISCUSSION: The obtained nanocrystals had particle size of 168 nm and were spherical in shape. The nanocrystals exhibited fivefold increase in kinetic solubility as compared to pure drug and 85% dissolution in 60 min. PXRD studies established the retention of crystalline polymorphic form II. The in vivo pharmacokinetic study demonstrated that the Cmax and AUC of nanosized BCT were about 3.5 times higher as compared to pure drug. CONCLUSION: Nanosizing of BCT significantly improved the pharmacokinetic profile of the drug administered to rats. Prepared nanocrystals were found to be stable over the entire stability period. Thus the use of amphiphilic polymer like Soluplus singularly helped in efficient size reduction and stabilization of the drug.

Chitosan-reduced gold nanoparticles: a novel carrier for the preparation of spray-dried liposomes for topical delivery.

Exposure of skin to various chemical and physical agents results in excessive stress to the outermost cell layer of the skin, causing different degenerative effects that can be minimized by using antioxidant formulations. The major challenge, in this regard, is to develop a formulation, which can prevent photodegradation of the actives, thus allowing a significant amount to be deposited at the site. In recent decades, liposomal formulations have been extensively employed to overcome the barrier properties of the skin and photodegradation of actives. In the present study, chitosan-reduced gold nanoparticles were investigated for its potential as a carrier to prepare liposomes by a spray-drying method. Liposomes so obtained were characterized for phospholipid recovery, diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, particle size, zeta potential, encapsulation efficiency, and deposition of drug and gold nanoparticles in the rat skin. Further, a liposomal gel formulation was prepared using Carbopol® 980 NF (Noveon Systems, Kochi, India) and evaluated for drug deposition in the skin. Antioxidant activity of vitamin C encapsulated in gold liposomes was determined on a human leukemia (HL-60) cell line. The use of gold nanoparticles as a carrier showed improved phospholipid recovery and thus overcomes the liposome scalability problem. DRIFT spectra confirmed the presence of phospholipid in the formulation. Liposomal gel showed improved drug deposition, as compared to control and marketed preparations. A more interesting contribution of the chitosan-reduced gold nanoparticles was an enhanced antioxidant activity seen in case of the vitamin C-loaded gold liposomal formulation. Liposomal formulation was found to be stable for 3 months at 30°C and 65% relative humidity.

Biosynthesis of gold nanoparticles using therapeutic enzyme: in-vitro and in-vivo efficacy study.

The present contribution deals with the synthesis of gold nanoparticles using a therapeutic enzyme serratiopeptidase followed by the in-vitro and in-vivo evaluation to demonstrate the retention of therapeutic activity of the enzyme. Here, gold nanoparticles were synthesized at 25 degrees C and physiological pH 7. The formation of serratiopeptidase reduced gold nanoparticles was confirmed by UV visible spectroscopy, transmission electron microscopy, X-ray diffractometer and fourier transform infrared spectroscopy. Proteolytic enzyme activity assay revealed that the composite contained 64% enzyme capped on AuNps while the remaining 36% enzyme remained in the supernatant. Further, retention of enzymatic activity of these nanoparticles was confirmed by in-vitro casein agar plate method as well as by in-vivo anti-inflammatory activity performed in experimental animals. Six month stability study at ambient temperature (25 degrees C) revealed that gold nanoparticles were stable as indicated by no shift in the surface plasmon band. In conclusion, physiological condition is an important process condition for controlled synthesis of highly stable gold nanoparticle with respect to retention of enzymatic activity. Also use of gold nanoparticles as a carrier for serratiopeptidase led to an improved anti-inflammatory response.

Solubility and stability enhancement of atorvastatin by cyclodextrin complexation.

The objective of the study was to increase the solubility, stability, and dissolution rate of atorvastatin calcium (ATN Ca), a poorly water-soluble 3-hydroxy 3-methyl glutaryl CoA (HMG-CoA) reductase inhibitor through inclusion complexation with beta-cyclodextrin (beta-CD). The phase solubility profile indicated that the solubility of ATN Ca was significantly increased in the presence of beta-CD and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Solid complexes prepared by physical mixing, kneading, co-evaporation, and freeze-drying methods were characterized using differential scanning calorimetry, fourier transform infrared spectroscopy, and powder X-ray diffractometry. In vitro studies showed that the solubility and dissolution rate of ATN Ca were significantly improved by complexation with beta-CD with respect to the drug alone. In contrast, freeze-dried product showed higher solubility and dissolution rates than the other complexes. ATN Ca unit dosage form was developed and evaluated for physico-chemical properties, stability, and dissolution rate. The stability of tablets was studied and no significant changes were detected in the dissolution profile of tablets after 1 month.

Chitosan reduced gold nanoparticles as novel carriers for transmucosal delivery of insulin.

PURPOSE: Colloidal metallic systems have been recently investigated in the area of nanomedicine. Gold nanoparticles have found themselves useful for diagnostic and drug delivery applications. Herein we have reported a novel method for synthesis of gold nanoparticles using a natural, biocompatible and biodegradable polymer; chitosan. Use of chitosan serves dual purpose by acting as a reducing agent in the synthesis of gold nanoparticles and also promotes the penetration and uptake of peptide hormone insulin across the mucosa. To demonstrate the use of chitosan reduced gold nanoparticles as carriers for drug delivery, we report herein the transmucosal delivery of insulin loaded gold nanoparticles. MATERIALS AND METHODS: Gold nanoparticles were prepared using different concentrations of chitosan (from 0.01% w/v up to 1% w/v). The gold nanoparticles were characterized for surface plasmon band, zeta potential, surface morphology, in vitro diffusion studies and fluorescence spectroscopy. The in vivo studies in diabetic male Wistar rats were carried out using insulin loaded chitosan reduced gold nanoparticles. RESULTS: Varying concentrations of chitosan used for the synthesis of gold nanoparticles demonstrated that the nanoparticles obtained at higher chitosan concentrations (>0.1% w/v) were stable showing no signs of aggregation. The nanoparticles also showed long term stability in terms of aggregation for about 6 months. Insulin loading of 53% was obtained and found to be stable after loading. Blood glucose lowering at the end of 2 h following administration of insulin loaded gold nanoparticles to diabetic rats was found to be 30.41 and 20.27% for oral (50 IU/kg) and nasal (10 IU/kg), respectively. Serum gold level studies have demonstrated significant improvement in the uptake of chitosan reduced gold nanoparticles. CONCLUSIONS: The synthesis of gold nanoparticles using a biocompatible polymer, chitosan would improve its surface properties for binding of biomolecules. Our studies indicate that oral and nasal administration of insulin loaded chitosan reduced gold nanoparticles has led to improved pharmacodynamic activity. Thus, chitosan reduced gold nanoparticles loaded with insulin prove to be promising in controlling the postprandial hyperglycemia.

Development of vitamin loaded topical liposomal formulation using factorial design approach: drug deposition and stability.

Long-term exposure of the skin to UV light causes degenerative effects, which can be minimized by using antioxidant formulations. The major challenge in this regard is that a significant amount of antioxidant should reach at the site for effective photoprotection. However, barrier properties of the skin limit their use. In the present study, Vitamin E acetate was encapsulated into liposome for improving its topical delivery. However preparation of liposomes is very difficult due to number of formulation variables involved therein. In the present work systematic statistical study for the formulation of liposomes for topical delivery of Vitamin E using the factorial design approach was undertaken. Amount of phospholipid (PL) and cholesterol (CH) were taken at three different levels and liposomes were prepared using ethanol injection method. Liposomes were characterized for encapsulation efficiency, vesicle size, zeta potential, and drug deposition in the rat skin. Gels containing liposomal dispersion (batch with higher skin deposition of VE) were prepared in Carbopol 980 NF and were characterized for gel strength, viscosity and drug deposition in the rat skin. Stability of liposome dispersion and gel formulation was studied at 30 degrees C/65% RH for 3 months. Results of regression analysis revealed that vesicle size and drug deposition in the rat skin were dependent on the lipid concentration and lipid:drug ratio. Drug deposition in rat skin had an inverse relationship with respect to PL and CH concentration. Prepared liposomal dispersion (50 mg PL:6 mg CH) showed seven-fold increase in drug deposition compared to control (plain drug dispersion). Gel formulation demonstrated six-fold and four-fold increase in drug deposition compared to control gel and marketed cream, respectively. Liposome dispersion and gel formulation were found to be stable for 3 months. Factorial design was found to be well suited to identify the key variables affecting drug deposition. Improved drug deposition from liposomal preparations demonstrates its potential for dermal delivery.