Nilutpal Sharma Bora

Exploration of ethyl anthranilate-loaded monolithic matrix-type prophylactic polymeric patch

Compromised stability of pharmaceutical formulations loaded with volatiles is a serious problem associated with devices designed to deliver volatile compounds. The present study has been focused to evaluate the stability potential of matrix-type polymeric patches composed of volatile ethyl anthranilate for prophylaxis against vector-borne diseases. Ethyl anthranilate-loaded matrix-type polymeric patches were fabricated by solvent evaporation method on an impermeable backing membrane and attached to temporary release liners. Stability testing of the polymeric patches was performed as per the International Conference on Harmonization (ICH) guidelines for 6 months under accelerated conditions. In addition, the quantification of residual solvents was also performed as per the ICH guidelines. After conducting the stability studies for 6 months, the optimized patches showed the best possible results with respect to uniformity of drug content, physical appearance, and other analytical parameters. Furthermore, the amount of residual solvent was found well below the accepted limit. Thus, the present report outlined the analytical parameters to be evaluated to ensure the stability of a certain devices consisting of volatile compounds.

In vitro antihelmintic activity of bark extract of Cinnamomum bejolghota (Buch.-Ham.) in Indian adult earthworm (Pheretima posthuma)

Abstract Objective To carry out an exhaustive study with a view to substantiate the therapeutic potential of methanolic and aqueous extract of bark of Cinnamomum bejolghota ( C. bejolghota ) against Pheretima posthuma which is used as experimental model for helmintic. Methods Thirty-six adult earthworms of 3.5–5.0 cm length were collected from university campus of Dibrugarh. Nine groups containing four worms in each group were divided for the experiment. About 0.9% (w/v) of normal saline solution, 25 mg/mL, 50 mg/mL, 100 mg/mL each of standard drug albendazole and methanolic, aqueous extract of bark of C. bejolghota were freshly prepared before commencement of the study. Earthworms were observed for paralysis and death time which is recorded in minute. Results Crude methanolic extract with concentrations of 25 mg/mL, 50 mg/mL and 100 mg/mL produced dose-dependent paralysis. All results were expressed as the mean±SEM using One-way ANOVA. The difference in values at P Conclusions From the investigation, conclusion can be drawn that the methanolic bark extract of C. bejolghota showed better activity than aqueous extract of the same to treat intestinal worm infections. In comparison with the standard drug albendazole, methanolic bark extract of the plant showed significant antihelminthic activity.

Study on Antibacterial Activity of the Bark of Garcinia lanceifolia Roxb.

Garcinia lanceifolia Roxb. is an important and endemic medicinal plant of Assam which has been used by various ethnic communities of Northeast India to treat various disorders like dysentery, dyspepsia, and biliousness. The plant is considered to be containing much medicinal value and is also eaten raw or made into pickles by the local people. Our present study has been focused on the evaluation of the antibacterial activity of the methanolic extract of the bark of Garcinia lanceifolia which may lead us to a scientific evidence of the use of this plant in cases of dysentery and diarrhoea.

Safety assessment and toxicological profiling of a novel combinational sunprotective dermal formulation containing melatonin and pumpkin seed oil

&NA; Ultraviolet (UV) radiation exposure has been known to cause irreparable damages to human skin. The daunting risk of UV radiation exposure faced by military personnel led to the development of a sunscreen formulation which has superior sun protection factor combined with the ability to counteract reactive oxygen species. The present work deals with the preclinical safety evaluation of the sunscreen formulation comprising of four US FDA approved UV filters; namely avobenzone, octinoxate, oxybenzone, titanium dioxide along with melatonin and pumpkin seed oil, via OECD protocols of assessing acute oral and dermal toxicity; skin sensitizing; skin irritating; ocular irritating and genotoxic potential. Both oral and dermal LD50 values were found to be >2000 mg/kg body weight in adult Wistar albino rats using acute dermal and oral toxicity tests. The sunscreen formulation was found to be non‐sensitizing to the skin of guinea pigs and non‐irritating to both skin and eyes of rabbits. The sunscreen formulation was also found to be non‐mutagenic which was affirmed by a battery of genotoxicity and muagenicity assays. The results obtained from this preclinical study indicated that the sunscreen formulation is non toxic and safe in animal models. This study along with additional preclinical evaluations may serve as a basis for considering the formulation as a potential candidate for further trials to establish its efficacy, tolerability and applicability. Graphical abstract Figure. No caption available. HighlightsA sunscreen formulation using four US FDA approved ingredients along with melatonin and pumpkin seed oil was developed.Dermally, the sunscreen did not cause toxicity; irritation or sensitization in rats, rabbits and guinea pigs respectively.Instillation of the formulation into rabbit eye caused low adversities, indicating ocular safety and non irritancy.Oral administration of the sunscreen did not demonstrate mortality, gross toxicity or histopathological alterations in rats.A battery of genotoxicity assays confirmed that the formulation was non mutagenic.

Validated RP-HPLC/DAD Method for the Quantification of Insect Repellent Ethyl 2-Aminobenzoate in Membrane-Moderated Matrix Type Monolithic Polymeric Device

A simple, accurate and sensitive reversed-phase high-performance liquid chromatographic (RP-HPLC) method has been developed for the estimation of ethyl 2-aminobenzoate (EAB) in a matrix type monolithic polymeric device and validated as per the International Conference on Harmonization guidelines. The analysis was performed isocratically on a ZORBAX Eclipse plus C18 analytical column (250 × 4.4 mm, 5 μm) and a diode array detector (DAD) using acetonitrile and water (75:25 v/v) as the mobile phase by keeping the flow-rate constant at 1.0 mL/min. Determination of EAB was not interfered in the presence of excipients. Inter- and intra-day relative standard deviations were not higher than 2%. Mean recovery was between 98.7 and 101.3%. Calibration curve was linear in the concentration range of 0.5-10 µg/mL. Limits of detection and quantification were 0.19 and 0.60 µg/mL, respectively. Thus, the present report put forward a novel method for the estimation of EAB, an emerging insect repellent, by using RP-HPLC technique.

Prospects of topical protection from ultraviolet radiation exposure: a critical review on the juxtaposition of the benefits and risks involved with the use of chemoprotective agents

Abstract Solar ultraviolet (UV) radiation exposure is known to cause inevitable damage to human skin via different mechanisms which include disruption of genetic material and generation of free radicals. In the ever emerging field of photoprotective agents, there have been constant endeavors to uphold the standards for optimum protection from solar UV-induced damages which include alarming conditions ranging from severe keratosis to malignant transformation of skin cells. Out of the various methods available for photoprotection, chemical photoprotective agents are most popular due to its ease of applicability, availability, and efficacy. However, the benevolences of chemophotoprotective agents are not excluded from the fact that all chemical agents are bound to suffer predestined consequences of toxicity and unwanted side effects. The present article focuses on the basic knowledge pertaining to achieve adequate sun protection and also on the beneficial and risk factors of using chemical agents as photoprotective formulations. The article highlights the US Food and Drug Administration (FDA) approved and unapproved UV filters; and also sheds light on the overall measures to protect an individual from UV radiation exposure, dispel misconceptions and present the newer technologies that are available in the market to accomplish ideal sun protection.

Determination of LCt50 of aerosolized paraquat and its pulmonary toxic implications in non-anesthetized rats

Abstract Paraquat (PQ), a highly popular agricultural herbicide, is a serious occupational hazard with lethality reported at doses as low as 35 mg/kg body weight with intoxication occurring via inhalation or dermal route. The main objective of this study was to determine the median lethal concentration (LCt50) of paraquat through whole body exposure in adult male Wistar rats. Aerosolized PQ dissolved in water was delivered in a dose-dependent manner, to fully conscious rats confined in whole body plethysmograph (WBP), in a nebulized form with concentrations ranging from 40–200 mg/kg of air over a 4 h exposure period. Animals were observed up to 24–48 h post-exposure to observe any lethality. LCt50 estimates (±95% confidence interval) were obtained from the sequential stage-wise experiments using probit analysis. Rat lungs were examined radiologically and histopathologically. Gas chromatography–mass spectrometry (GC-MS) analysis determined the correlation of PQ accumulation in the lungs with the actual exposed dose of PQ. The actual LCt50 was found to be 218 g·min/m3 whereas 57.9 ± 2.90 µg/g of PQ accumulated in the lungs of each lifeless animal. All animals exhibited severe respiratory changes and pulmonary abnormalities. This study demonstrated that when compared with the actually exposed dose, the amount of PQ that accumulated in the lungs was very low, but enough to cause death in 50% of animal population and cause pulmonary abnormalities in each of the experimental animal. The PQ exposure carried out in WBP also facilitated the dermal absorption of aerosolized PQ, which replicated the real-life situation in workers operating with PQ.

Safety evaluation of an oat grain alkaloid gramine by genotoxicity assays

Abstract Gramine is a natural indole alkaloid that has been isolated from different raw plants occurring mainly in Avena sativa, etc. The study was aimed to investigate the possible in vitro antioxidant, in vitro mutagenic, in vitro antimutagenic, and in vivo genotoxic activity of gramine using ferric reducing ability of plasma (FRAP) assay, Metal chelating, Ames bacterial reverse mutation test, and the mouse bone marrow micronucleus assay as well as chromosomal aberration. Four concentrations of gramine viz. 250, 500, 1000, and 2000 μg/mL were evaluated for its antioxidant activity in FRAP Assay and Metal Chelating Test. Four concentrations of gramine (1250 μg/plate, 2500 μg/plate, 5000 μg/plate, and 10 000 μg/plate) were employed in Salmonella typhimurium strains to study the mutagenicity in the presence and absence of standard mutagens, 2-aminofluorene (2-AF), sodium azide (SA), and 2-nitrofluorene (2-NF). Three doses, i.e. 0.1, 0.2, and 0.3 × the LD50 of gramine (i.e. 50 mg/kg, 100 mg/kg, and 150 mg/kg) were administered orally to either sex of Swiss albino mice for 48 h to study the genotoxic activity in micronucleus assay as well as chromosomal aberration. Gramine showed potent antioxidant activity in both the assay. Gramine at the given dose lacks mutagenicity as well as found to possess antimutagenic efficacy. Interestingly, S9 enzymes increase the antimutagenic activity in a dose-dependent manner. There was no significant increase in the frequency of micronucleated polychromatic erythrocytes (MNPCEs), as well as no significant difference in the percentage of chromosomal aberrations was observed between the gramine groups and the negative groups but percentage of polychromatic erythrocytes (PCEs) is found to be higher in all the gramine groups. These results indicate significant antioxidant, non-mutagenic as well as non-genotoxic activity of gramine in vitro and in vivo in the given doses.

Preliminary phytochemical screening, in-vitro antioxidant activity, total polyphenolic and flavonoid content of Garcinia lanceifolia Roxb. and Citrus maxima (Burm.) Merr. -

Garcinia lanceifolia and Citrus maxima are two indigenous fruits of East India, particularly Assam; which has been used in various folkloric medicines to treat disorders ranging from diarrhoea and jaundice to stomach and heart problems. The main aim of this study was to establish and compare the antioxidant potential of these two plants. The methanolic extracts of the bark of G. lanceifolia and C. maxima were tested for their antioxidant potential using various established in-vitro assay procedures. The estimation of the total phenolic and total flavonoid content were also carried out. The phytochemical screening was also done prior to these assays, and it revealed that both the extracts were found to contain tannins and phenolic compounds and flavonoids along with other phytoconstituents. The results reveal that both these plants have a considerable amount of antioxidant activity which can be compared with each other and also the standards.