Development of repaglinide loaded solid lipid nanocarrier: selection of fabrication method

Repaglinide solid lipid nanoparticles (RG-SLN) were fabricated using stearic acid as lipid. Pluronic F68 (PLF68) and soya lecithin were used as a stabilizer. SLNs were prepared by modified solvent injection and ultrasonication methods. SLNs prepared with modified solvent injection method have larger particle size (360+/-2.5nm) than prepared with ultrasonication method (281+/-5.3nm). The zeta potential of the prepared formulations by these two methods varied from - 23.10 +/-1.23 to -26.01 +/-0.89 mV. The maximum entrapment efficiency (62.14 +/-1.29%) was obtained in modified solvent injection method. The total drug content was nearly same (98%) in both the methods. In vitro release studies were performed in phosphate buffer (pH 6.8) with 0.5% sodium lauryl sulphate (SLS) using dialysis bag diffusion technique. The cumulative drug release was 30% and 50% within 2 hrs in modified solvent injection and ultrasonication method, respectively. This indicates that RG-SLN prepared from modified injection method released the drug more slowly than SLNs prepared with ultrasonication method. Differential scanning calorimetry indicates that repaglinide (RG) entrapped in the solid lipid nanoparticles (SLN) exist in an amorphous or molecular state. Repaglinide loaded solid lipid nanoparticles prepared with both methods were of spherical shape as observed by transmission electron microscopy (TEM). These results suggest that modified solvent injection method is more suitable for preparation of repaglinide SLNs using stearic acid.

Morphological characteristics of primary dentition in children of Chennai and Hyderabad

OBJECTIVE

The purpose of this study was to investigate the morphological characteristics of deciduous teeth of children in Chennai and Hyderabad, by establishing normal data on the mesiodistal and buccolingual crown dimensions in 3-5 year old children.

MATERIALS AND METHODS

Study casts of 200 children (100 boys and 100 girls) from two groups (Chennai and Hyderabad) were used in this study. Digital caliper was used to measure the mesiodistal and buccolingual dimensions.

RESULTS AND CONCLUSION

Significant differences were found in the mean values of mesiodistal and buccolingual diameters of primary teeth, in which boys generally had larger crown diameters than girls.

Management of an impacted and transposed maxillary canine

Maxillary canine-lateral incisor transposition is a relatively rare anomaly, with both dental and facial esthetic implications. This is a case report of a maxillary canine-lateral incisor transposition that was successfully treated by surgical-orthodontic treatment followed by esthetic reshaping of the involved teeth.

Stimulus-responsive targeted nanomicelles for effective cancer therapy

Emerging nanotechnology has already developed various innovative nanomedicines. Nanomicelles, self-assemblies of block copolymers, are promising nanomedicines for targeted drug delivery and imaging. Stimulus-responsive targeted nanomicelles are designed to release drugs based on stimuli such as pH, temperature, redox potential, magnetism and ultrasound. This article will focus on recent advancements in the design of stimulus-responsive targeted nanomicelles loaded with anticancer drugs to fulfill the challenges associated with cancer cells (e.g., multidrug resistance) for the effective treatment of cancer. The significant toxicity issues and a possible future perspective associated with nanomicelles are also discussed here.

Poly (D, L-lactide) nanosuspensions of risperidone for parenteral delivery: formulation and in-vitro evaluation

Risperidone, an "atypical" antipsychotic drug, having large scope for prolonged psychotic treatments through novel parenteral drug delivery systems. Polymeric nanoparticles suspensions containing risperidone made of poly (D, L-Lactide) were designed by nanoprecipitation method using polymeric stabilizer (Pluronic F-68 or Pluronic F-127). The prepared nanosuspensions were characterized for particle size by photon correlation spectroscopy and scanning electron microscopy. The free dissolved drug in the nanosuspension was determined by bulk equilibrium reverse dialysis bag technique. In vitro release studies were carried out using dialysis bag diffusion technique. The particle size of the prepared nanoparticles in the nanosuspensions ranged between 78-184 nm. Nanoparticles of risperidone in the nanosuspensions were obtained with high encapsulation efficiency (91-94 %). The drug release from the risperidone nanosuspension was sustained in some batches for more than 24 h with 75% drug release whereas release from risperidone solution showed release within 1.5 h. The release pattern of drug is analyzed and found to follow first order equation and Fickian diffusion kinetics. These studies suggest the feasibility of formulating risperidone loaded poly (D, L-Lactide) nanoparticles suspension for the treatment of psychotic disorders.

Enhanced transdermal delivery of ketoprofen from bioadhesive gels

The aim of this study was to evaluate and compare the in vitro and in vivo transdermal potential of bioadhesive gels of ketoprofen by using gelling polymers like sodium carboxymethylcellulose, xanthan gum, poloxamer 407 and carbopol 934P as bioadhesive polymer with and without penetration enhancer (oleic acid). The effect of oleic acid as a penetration enhancer was examined when it was added to the bioadhesive formulations. Gels were evaluated for bioadhesive force and viscosity. To study the in vitro potential of these formulations, permeation studies were performed with Franz diffusion cell using excised rat abdominal skin. Carrageenan induced rat paw edema model was used to investigate their in vivo performance. The commercial formulation of ketoprofen was used as a reference formulation. The in vitro permeation studies indicate that ketoprofen bioadhesive gel of poloxamer 407 with penetration enhancer was superior to gels of sodium carboxymethylcellulose and xanthan gum with penetration enhancer (oleic acid). The permeation rate of ketoprofen from poloxamer 407 based bioadhesive gel with 15% v/w penetration enhancer was higher (rat abdominal skin flux = 0.421 +/- 0.032 mg/cm(2)/h) than the permeation rate of sodium carboxymethylcellulose and xanthan gum based bioadhesive gel with 15% v/w penetration enhancer. In the paw edema test poloxamer 407 based bioadhesive gel with 15% v/w penetration enhancer showed the best permeation and effectiveness. The in vitro and in vivo studies showed that bioadhesive gels of ketoprofen could be used for effective therapy.

PLGA nanoparticle formulations of risperidone: preparation and neuropharmacological evaluation

The aim of this work was to develop extended-release poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles of risperidone and thermal-responsive in situ gel containing risperidone nanoparticles for parenteral (subcutaneous) delivery and to reduce the dose-dependent extrapyramidal side effects of risperidone. PLGA nanoparticles of risperidone were designed by nanoprecipitation method using polymeric stabilizer (Poloxamer 407). The prepared nanoparticles were characterized for particle size by photon correlation spectroscopy and atomic force microscopy. Poloxamer 407-based in situ gel containing PLGA nanoparticles of risperidone was prepared by modified cold method to control the initial rapid release from the nanoparticles. The in vivo efficacy (antipsychotic effect) of prepared formulations (nanoparticles and in situ gel containing nanoparticles) was studied by administering them subcutaneously to mice. Extrapyramidal side effects of the formulations were also studied. The particle size of the prepared nanoparticles ranged between 85 and 219 nm. About 89% to 95% drug encapsulation efficiency was achieved when risperidone was loaded at 1.7% to 8.3% by weight of the polymer. During in vivo studies prepared risperidone formulations showed an antipsychotic effect that was significantly prolonged over that of risperidone solution for up to 72 hours with fewer extrapyramidal side effects. The prolonged effect of risperidone was obtained from the risperidone formulations administered subcutaneously, and this may improve the treatment of psychotic disorders by dose reduction.

FROM THE CLINICAL EDITOR

The development of extended-release poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles of risperidone is reported in this paper, along with the development of thermal-responsive in situ gel containing risperidone nanoparticles for parenteral (subcutaneous) delivery and to reduce the dose-dependent extrapyramidal side effects. In vivo studies showed a significantly prolonged antipsychotic effect with fewer extrapyramidal side effects.

Targeted nanomedicines: effective treatment modalities for cancer, AIDS and brain disorders

Novel technology in the nanomedicine field is expected to develop innovative products as targeted drug-delivery approaches. Targeted drug delivery of various drugs for the treatment of cancer, AIDS and brain disorders is the primary research area in which nanomedicines have a major role and need. This review is concerned with emerging targeted nanomedicines (polymeric nanoparticles, solid lipid nanoparticles, polymeric micelles, dendrimers, liposomes, gold nanoparticles and magnetic nanoparticles) and multifunctional carriers capable of combining targeted drug delivery and imaging (polymeric micelles, dendrimers and magnetic nanoparticles) in the field of pharmaceutical applications. The significant toxicity issues associated with these nanomedicines are also explored here.

Children's behavior pattern and behavior management techniques used in a structured postgraduate dental program

BACKGROUND

Anxiety and fear remain the primary emotion of a child entering a dental office. Successful pediatric dentistry depends not only on the dentist's technical skills, but also on his ability to acquire and maintain a child's cooperation.

METHODS

A retrospective study was done using the case records of 247 children, to evaluate their behavior patterns, based on the Wright's modification of Frankl's behavior rating scale. Various behavior management techniques like the tell-show-do, reinforcements, voice control, and hand over mouth exercise used in the postgraduate section of the Department of Pediatric Dentistry, Meenakshi Ammal Dental College, Chennai, India, were also evaluated in this study.

RESULTS

Behavior of the children improved on the subsequent visits. Tell-show-do was the most common behavior management technique used and more aversive management techniques were rarely used in managing children in the dental office.

CONCLUSION

Proper assessment of children's behavior helps the dentist to plan appointments and render effective and efficient dental treatment. Appropriate use of management techniques can improve the child's behavior in subsequent dental visits.

Quantitative assessment of IgA levels in the unstimulated whole saliva of caries-free and caries-active children

Saliva is commonly referred to as the blood stream of the oral cavity. It has many functions, one of the major functions being protection of teeth against dental caries. There are many components in saliva, each one having a specific role in the prevention of dental caries. The composition of saliva varies from individual to individual and in the same individual it varies between the glands. The composition of whole saliva, especially when unstimulated, has gained much interest, because it is this which constantly bathes the teeth. The aim of this study was to determine the IgA levels in the unstimulated whole saliva of caries-free and caries-active children aged 3-6 years and to correlate its role in protection of the tooth against dental caries.

Studies on biodegradable polymeric nanoparticles of risperidone: in vitro and in vivo evaluation

AIM

The aim of this work was to develop extended-release risperidone nanoparticles for parenteral delivery (intravenous) and to reduce the dose-dependent extrapyramidal side effects of risperidone.

METHODS

Polymeric nanoparticles containing risperidone made of poly (epsilon-caprolactone) were designed by the nanoprecipitation method using polymeric stabilizers (poloxamers). The in vivo efficacy of prepared formulations and the risperidone solution was studied by administering them intravenously to apomorphine-treated mice. Extrapyramidal side effects of the risperidone and its formulations were also studied.

RESULTS

The particle size of the prepared nanoparticles ranged between 99 and 304 nm. Approximately 78-85% drug-encapsulation efficiency was achieved when risperidone was loaded at 1.7-4.1% by weight of the polymer. During in vivo studies, prepared risperidone-containing formulations showed a significant prolonged antipsychotic effect than that of risperidone solution, also having less extrapyramidal side effects.

CONCLUSION

The prolonged effect of risperidone was obtained from the nanoparticles of risperidone administered by the intravenous route and this may improve the treatment of psychotic disorders by dose reduction.

Management of a child with autism and severe bruxism: a case report

Autism is a developmental disorder characterized by severe deficits in social interaction and communication. A wide spectrum of medical and behavioral symptoms is exhibited by children with autism, which makes routine dental care very difficult in them. Bruxism or forceful grinding of teeth is one of the sleep problems commonly observed in children with autism. Our patient, a 4-year-old male child with autism, presented with complaints of pain and sensitivity of the teeth. There was history of excessive grinding and clenching of teeth. Limited oral examination revealed severe attrition of all primary teeth. Treatment was planned under general anesthesia because of his poor cognitive abilities. Full-mouth rehabilitation, including placement of stainless steel crowns for all primary molars, was done. Following treatment there was a significant decrease in the grinding habit over the next 2 months. Although the communication and behavioral problems in children with autism pose challenges for the dentist, treatment with proper planning and a lot of patience can definitely make a difference.

Effect of oil pulling on Streptococcus mutans count in plaque and saliva using Dentocult SM Strip mutans test: a randomized, controlled, triple-blind study

BACKGROUND

Oil pulling has been used extensively for many years, without scientific evidence or proof, as a traditional Indian folk remedy to prevent teeth decay, oral malodor, bleeding gums, dryness of throat and cracked lips, and for strengthening the teeth, gums, and jaws.

AIMS

The aim of this study was to evaluate the effect of oil pulling with sesame oil on the count of Streptococcus mutans in plaque and saliva of children, using the Dentocult SM Strip mutans test, and to compare its efficacy with that of chlorhexidine mouthwash.

MATERIALS AND METHODS

Twenty age-matched adolescent boys were selected based on information obtained through a questionnaire. They were divided randomly into two groups: the control or chlorhexidine group (group I) and the study or oil pulling group (group II); there were ten subjects in each group. Plaque and saliva samples were collected from all the 20 subjects on the strips from the Dentocult SM kit and, after incubation, the presence of S. mutans was evaluated using the manufacturers' chart. The study group practiced oil pulling with sesame oil and the control group used chlorhexidine mouthwash for 10 min every day in the morning before brushing. Samples were collected from both groups after 24 h, 48 h, 1 week, and 2 weeks and the efficacy of oil pulling was compared with that of chlorhexidine mouthwash.

RESULTS

There was a reduction in the S. mutans count in the plaque and saliva samples of both the study and the control groups. The reduction in the S. mutans count in the plaque of the study group was statistically significant after 1 and 2 weeks (P=0.01 and P=0.008, respectively); the control group showed significant reduction at all the four time points (P=0.01, P=0.04, P=0.005, and P=0.005, respectively, at 24 h, 48 h, 1 week, and 2 weeks). In the saliva samples, significant reduction in S. mutans count was seen in the control group at 48 h, 1 week, and 2 weeks (P=0.02, P=0.02, P=0.008, respectively).

CONCLUSION

Oil pulling can be used as an effective preventive adjunct in maintaining and improving oral health.

First dental visit of a child

OBJECTIVES

The aim of the study was to assess the common chief complaints of the Indian children and the average age group at which they report for in their first dental visit.

MATERIALS AND METHODS

A retrospective study was carried out using the case records of 716 children who reported to the postgraduate section of Department of Pediatric dentistry, Meenakshi Ammal Dental College, Chennai, in 2007. The age groups of the children were divided into three categories 0-3 years, 3-6 years and 6-12 years. The various chief complaints were categorised as follows, Orientation to prevention, Routine visit, Deposits/Discoloration, Habits, Unerupted/Missing or Extra Tooth, Pain, Dental caries, Malocclusion, Trauma, others. The average age group and most common complaint at the first dental visit was assessed. A prospective study was done in January 2008, were 215 children were screened. The assessment was made as explained above.

RESULTS

Retrospective study Maximum number of children who reported for their first dental visit was between 6-12 years (59.08%). Most common chief complaint for the visit was pain (42.04%). Second common complaint being dental caries (28.49%). Prospective study Maximum number of children who reported for their first dental visit was between 6-12 years (69.77%). Most common chief complaint was dental caries (34.88%). Second common complaint being pain (27.91%).

CONCLUSION

Children report for the first dental visit most commonly only after 6 years and for complaints like pain and dental caries. Orientation to prevention is not considered and preventive dentistry is yet to reach the common population in India.

Effect of fluoride varnish on Streptococcus mutans counts in plaque of caries-free children using Dentocult SM strip mutans test: a randomized controlled triple blind study

Dental caries is one of the most prevalent infectious diseases and although of multifactorial origin, Streptococcus mutans is considered the chief pathogen in its development. Fluoride is one of the most effective agents used for the reduction of dental caries apart from oral hygiene maintenance.

AIMS

The aim of this study was to estimate the counts of Streptococcus mutans and to evaluate the effect of Fluor Protector fluoride varnish on these counts in the plaque of caries-free children using Dentocult SM Strip Mutans.

MATERIALS AND METHODS

Thirty caries-free subjects were selected for the study based on the information obtained from a questionnaire and were randomly assigned to the control group consisting of ten subjects and the study group consisting of twenty subjects. Plaque samples were collected on the strips from the Dentocult SM kit and after incubation, the presence of Streptococcus mutans was evaluated using the manufacturer's chart. The study group was subjected to a Fluor Protector fluoride varnish application following which the samples were collected again after 24 hours.

RESULTS

The average Streptococcus mutans counts in the primary dentition of caries-free children before and after the application of Fluor Protector fluoride varnish were 10(4)-10(5) colony forming units (CFU)/ml and <10(4) CFU/ml respectively.

CONCLUSION

The results showed that the study group had a statistically significant reduction in the plaque Streptococcus mutans counts than the control group.

Preparation and characterization of nanoparticles containing an atypical antipsychotic agent

AIM

The aim of this work was to prepare poly(epsilon-caprolactone) nanoparticles of risperidone and to characterize them.

METHODS

Risperidone-loaded poly(epsilon-caprolactone) nanoparticles were prepared by the nanoprecipitation method using poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock polymeric stabilizer (PluronicF-68). The particles were characterized for particle size by photon correlation spectroscopy and transmission electron microscopy. The free dissolved drug in the nanosuspension was determined by the bulk equilibrium reverse dialysis bag technique. In vitro release studies were carried out using the dialysis bag diffusion technique.

RESULTS

The particle size of the prepared nanoparticles ranged from 90 to 300 nm. Nanoparticles of risperidone were obtained with high encapsulation efficiency (70-80%). The drug release from the risperidone nanoparticles was sustained in some batches for more than 24 h with 80% drug release, whereas release from risperidone in polyethylene glycol 400 solution showed release within 2 h.

CONCLUSION

These studies suggest the feasibility of formulating risperidone-loaded poly(epsilon-caprolactone) nanoparticles for the treatment of psychotic disorders.

Noonan syndrome: a case report

Noonan syndrome is a developmental disorder characterized by facial dysmorphia, short stature, cardiac defects and skeletal malformations. It may be sporadic or inherited as an autosomal dominant or recessive trait and occurs, one in 1,000-2,500 children. This is a case report of a 13 year-old girl who was referred by a general dental practitioner to a pediatric dentist for management. Full mouth dental rehabilitation was done and the child was brought to a dental institution for correction of orofacial and occlusal defects. Multidisciplinary treatment is the key to success in managing children with Noonan syndrome and the pediatric dentists play an important position to lead the health team.

Spontaneous closure of midline diastema following frenectomy

Maxillary midline diastema is a common aesthetic problem in mixed and early permanent dentitions. The space can occur either as a transient malocclusion or created by developmental, pathological or iatrogenical factors. Many innovative therapies varying from restorative procedures such as composite build-up to surgery (frenectomies) and orthodontics are available. Although literature says every frenectomy procedure should be preceded by orthodontic treatment, we opted for frenectomy technique without any orthodontic intervention. Presented herewith is a case report of a 9-year-old girl with a high frenal attachment that had caused spacing of the maxillary central incisors. A spontaneous closure of the midline diastema was noted within 2 months following frenectomy. The patient was followed up for 4 months after which the space remained closed and there was no necessity for an orthodontic treatment at a later stage.

Dental arch dimensions in primary dentition of children aged three to five years in Chennai and Hyderabad

OBJECTIVE

The purpose of this study was to assess the arch dimensions in primary dentition of 3-5 years old children in Chennai and Hyderabad. As no primary to the mixed dentition and determining the existence of sexual dimorphism.

METHODS

Children were selected fro various schools of both Chennai and Hyderabad, with complte set of primary dentition. Study casts were made and measurements of arch dimensions were made using digital sliding calipers. The data obtained was subjected to statistical analysis.

RESULTS

The mean values and standard deviations of the various arch dimensions are given in the tables.

CONCLUSION

Generally boys exhibited a greater arch dimensions than girls in both groups. Some of the dimensions showed a statistically significant mean values.

Macroabrasion in pediatric dentistry

One of the most frequent reasons for seeking dental care is discolored anterior teeth. Macroabrasion is a technique used for the removal of localized superficial white spots and other surface stains. This article has compiled three case reports with relevant clinical photographs of discolored teeth where the treatment regimen included macroabrasion alone as well as macro-abrasion in combination with anterior composite restorations.