Box-Behnken Design-Aided Validation and Optimization of a Stability-Indicating Reverse Phase-HPLC Method for the Estimation of Tamoxifen Citrate in Lipidic Nano-Vesicles

Stability indicating a reverse-phase HPLC analytical method for the quantification of tamoxifen citrate (TMX) in the bulk and lipidic nano-vesicles (LNVs) was developed. The optimized method was validated according to the ICH Q2 (R1) guidelines by following a three-factor interaction Box-Behnken design using Design-Expert® software. The responses measured at 236 nm were retention time (Rt), peak area, tailing factor (TF) and the number of theoretical plates. TMX was eluted best using the Luna® C18 LC Column along with a mobile phase of methanol (MeOH) and ammonium acetate buffer (AAB pH 4.5) 80:20 v/v mixture at 25 ± 2°C temperature. The currently developed method was linear in 100-5,000 ng/mL range with a detection limit of 4.55 ng/mL and a quantification limit of 13.78 ng/mL. The optimized method was utilized to evaluate the stability of TMX in different stress conditions by performing forced degradation studies. The results from the degradation study stipulated that on exposure to various stressors namely acid, alkali, oxidative, thermal and UV light, the TMX did not show considerable degradation except for UV light exposure. Further, the method was successfully used for the quantification of TMX in LNVs.

Evolving era of "sponges": Nanosponges as a versatile nanocarrier for the effective skin delivery of drugs

BACKGROUND

Nanosponge, as a carrier for skin delivery system for drugs, plays a vital role. It not only serves to administer the drug to the targeted layer of skin but also increases the drug retention and deposition on the skin.

OBJECTIVE

In this review, we aim to highlight the effects of several process and formulation variables prompting the characteristics of various nanosponges for the delivery of drugs into/ across the skin.

METHOD

In the present review article, over-all introduction of nanosponges, its preparation, characterstics features, advanatges, disadvantages, factors affecting their preparation are covered. Furthermore, an elaborative description of nanosponges for skin delivery and its toxicological perspective with some referential examples of nanosponge drugs have also been deliberated here.

RESULTS

Factors associated with the formation of nanosponges can directly or indirectly affect its efficacy in skin delivery of drugs. These nanoforms are efficient in delivering the drugs which possess lower aqueous solubility, therefore, the aqueous solubility of drugs possessing a narrow therapeutic window can easily be enhanced. It also helps in achieving targeted drug delivery, controlled release of drugs, increases bioavailability, reduces drug toxicity, decreases drug degradation, and many more.

CONCLUSION

Nanosponges have been identified as a potential drug delivery carriers into as well as across skin. Delivery of biologics such as vaccines, enzymes, peptides, proteins, and antibodies, is also gaining attention in the recent past.

Full Factorial Design for Development and Validation of a Stability-Indicating RP-HPLC Method for the Estimation of Timolol Maleate in Surfactant-Based Elastic Nano-Vesicular Systems

A novel isocratic stability-indicating chromatographic method was developed, optimized and validated using Design-Expert® following ICH guidelines for the quantification of Timolol maleate (TM). The intrinsic stability of TM was assessed by force degradation studies, which concluded no extensive degradation except under alkaline and oxidative conditions. TM was quantified accurately in the surfactant-based elastic vesicular system by separating it on Hypersil BDS C8 column using triethylamine in H2O (0.15%v/v; pH 3.0) and acetonitrile (ACN; 65:35%v/v). The influence of variable factors like mobile phase pH, injection volume (μL), flow rate (mL/min) and ACN content (%) on method responses were assessed using a full factorial design. The method was linear between 0.05 and 10 μg/mL with an R2 value of 0.9993. Limit of detection and limit of quantification were found to be 0.90 and 27.2 ng/mL. The method was specific, with recovery in plain drug solution of 89-92% and elastic nanovesicles of 90-93%. The experimental model was significant (P < 0.0001) as indicated by deliberate changes in the method analyzed through analysis of variance. The total drug content in elastic nanovesicles was estimated to be 9.53 ± 0.01 mg/20-mL dispersion and entrapment efficiency was 44.52 ± 0.73%. The developed method was rapid, economic and precise for the quantification of TM in bulk and vesicular system.

Box-Behnken design aided optimization and validation of developed reverse phase HPLC analytical method for simultaneous quantification of dolutegravir sodium and lamivudine co-loaded in nano-liposomes

A stability-indicating reversed-phase high-performance liquid chromatography method for simultaneous estimation of dolutegravir sodium and lamivudine encapsulated in the nanoliposomal formulation was developed. The chromatographic parameters namely, organic phase ratio, flow rate, and sample injection volume were selected as independent factors and were optimized by multivariate Box-Behnken design. Responses analyzed were retention time, peak area, and resolution. The optimized chromatographic method with Hypersil BDS C8 CN column as stationary phase and methanol and acetonitrile mixture and acidified Milli-Q water (pH 2.8, adjusted with 0.02% v/v orthophosphoric acid) as the mobile phase in an isocratic elution mode was validated according to parameters of International Conference on Harmonization Q1(R2) guidelines. The validated reversed-phase high-performance liquid chromatography method exhibited specificity for both dolutegravir sodium and lamivudine in the presence of degradation products as well as the liposomal matrix. This method was effectively utilized to determine the amount of drug entrapped and drug loading efficiency of dolutegravir sodium and lamivudine in a nano-liposomal formulation.

Simultaneous Estimation of Apremilast and Betamethasone Dipropionate in Microsponge-Based Topical Formulation using a Stability Indicating RP-HPLC Method: A Quality-by-Design Approach

A stability-indicating reverse phase high-performance liquid chromatography method was developed and validated for simultaneous quantification of apremilast (APL) and betamethasone dipropionate (BD) in bulk as well as drug loaded microsponges. Various mobile phase systems were screened to check the system suitability followed by force degradation analysis to determine APL and BD stability under varying stress conditions. A central composite design model was used to optimize the column temperature and flow rate using Design Expert® (9.0.1). One factor at a time approach with five independent factors were used to validate the robustness of the method. Finally, APL and BD were precisely and accurately quantified from drug loaded microsponges using the validated method. A favorable separation of APL and BD was obtained on a Phenomenex® Luna C18 column using a mixture of 50 mM phosphate buffer containing 0.1% triethylamine (pH 6.1) and acetonitrile (60:40%v/v) as mobile phase. Both the drugs were found to be stable when exposed to stressors such as heat-, light-, alkali-, acid- and peroxide-induced degradation. The calibration curves were found to be linear with appreciable limit of detection and limit of quantification. Recovery and percentage relative standard deviation of peak areas for APL and BD were found to be < 2.0% and 99-100% in bulk drug solution and <2.0% and 99-103% in microsponge formulation, respectively. Statistical analysis using analysis of variance indicated that the model was significant (P < 0.001). Hence, the developed method can be effectively used to quantify APL and BD, both in bulk as well as microsponge formulations.

Ethanolic extract of Moringa oleifera leaves alleviate cyclophosphamide-induced testicular toxicity by improving endocrine function and modulating cell specific gene expression in mouse testis

ETHNOPHARMACOLOGICAL RELEVANCE

Moringa oleifera Lam. is known for its nutritional and ethno medicinal values due to the presence of wide array of phytochemicals with multiple biological activities. We have previously reported that ethanolic extract of Moringa oleifera leaves (MOE) ameliorated cyclophosphamide (CP)-induced testicular toxicity and improved functional integrity of spermatozoa as well as spermatogenic cells.

AIM OF THE STUDY

The present study was planned to investigate whether the mitigation of CP-induced testicular toxicity by MOE is mediated via modulation of endocrine profile, genes associated with function of different cell types and enhancement of DNA repair response in spermatogonial cells.

MATERIALS AND METHODS

Adult Swiss albino mice (8 week) were injected with CP (100 mg/kg, one dose in a week for 3 weeks) and MOE (100 mg/kg, 5 doses in a week for 4 weeks) either alone or in combination intraperitoneally. At 35 day post CP injection (first dose), the functional characteristics such as count, motility, head morphology and DNA integrity were assessed in epididymal spermatozoa. Key reproductive hormones like testosterone, follicle stimulating hormone (FSH) and Inhibin B concentration were analyzed in serum and testis. In addition, mRNA expression of genes pertaining to the function of Leydig, Sertoli and spermatogonial cells as well as antioxidant enzymes were evaluated in the testis. To understand the DNA damage and repair process in germ cells, prepubertal (2 week) mice were administered with single dose of CP (200 mg/kg) and/or MOE (100 mg/kg) and analyzed for expression of DNA damage (γ-H2AX, P53 and Caspase3) and repair genes (Rad51 and Ku80) in isolated spermatogonial cells at various time points after treatment.

RESULTS

CP administration resulted in decrease in count, motility and increase in morphological defects and DNA damage in spermatozoa. Testosterone level was marginally decreased while there was a significant increase in FSH (p < 0.001) and decrease in inhibin B (p < 0.05) observed in CP treated mice. Administration of MOE prior to CP, improved sperm functional characteristics, decreased FSH and increased inhibin B levels. Expression of Abp was down-regulated while Transferrin, Fshr and Gata4 (Sertoli cell specific genes) were up-regulated in testis treated with CP. Administration of CP down-regulated the expression of Oct4 and Ddx4 (Spermatogonia specific genes). MOE administration was shown to ameliorate CP-induced damage by modulating the expression of genes specific to Sertoli and spermatogenic cells. Furthermore, MOE treatment reduced CP-induced DNA damage as evident from lower percentage of γ-H2AX positive spermatogonial cells.

CONCLUSION

Administration of MOE mitigated CP-induced testicular damage by improving blood and, intra-testicular hormonal milieu as well as modulating the expression of genes pertaining to Sertoli and spermatogonial cells.

Aniline-induced methaemoglobinaemia in a glucose-6-phosphate dehydrogenase enzyme deficient patient

A case of methaemoglobinaemia following ingestion of an aniline-containing material is described. The detrimental effect of methylene blue, the classical antidote of methaemoglobinaemia, in a patient with glucose-6-phosphate dehydrogenase deficiency is highlighted.

Hyperbaric oxygen therapy and free radical production: an experimental study in doxorubicin (Adriamycin) extravasation injuries

The role of hyperbaric oxygen (HBO) therapy in free radical-mediated tissue injury is not clear. HBO has been shown to enhance the antioxidative defense mechanisms in some animal studies, but HBO has also been reported to increase the production of oxygen free radicals. To investigate this controversy, we studied the effect of HBO in a doxorubicin (Adriamycin) extravasation model, because the cytotoxic activity of doxorubicin is partly related to its quinone structure, which leads to the formation of cytotoxic oxygen intermediates. Fifty-four Sprague-Dawley rats underwent injection of 0.3 ml doxorubicin solution (2 mg per milliliter) intradermally on both flanks as described by Rudolph and colleagues. Group I (N = 28) received HBO treatment (2 hours at 2 ATA) for 3 days prior to injection and 7 days postinjection. Group II (N = 26) received no HBO treatment. At 2, 3, and 5 weeks, the size of the ulcers and the surrounding area of alopecia in group I (+HBO) were significantly larger than in group II (-HBO): 112.2 mm2 vs. 42.8 mm2 (p < 0.01) and 1,132.2 mm2 vs. 364.8 mm2 (p < 0.005). Biochemical analysis of the biopsied skin ulcers, to measure the parameters of oxygen free radical production, indicated (similar) low levels of xanthine oxidase for both groups. However, significantly elevated levels of malonyldialdehyde (MDA), indirect evidence of free radical production, was observed in group I (+HBO) in comparison with group II (-HBO): 36.58 vs. 5.84 ng per minute per milligram protein (p < 0.001), which might indicate free radical-induced cellular injury. It is concluded that in this animal study the cytotoxicity of doxorubicin is potentiated by HBO therapy. The elevated levels of MDA suggest a direct additive cytotoxic effect by increased membrane lipid peroxidation. HBO therapy, therefore, might be deleterious in the early (preulcer) stage of doxorubicin extravasation.

Pyruvate inhibits growth of mammary adenocarcinoma 13762 in rats

The growth of implanted mammary adenocarcinoma 13762 was measured in rats consuming a liquid diet (35% fat, 18% protein, 47% carbohydrate) supplemented with pyruvate (37.3 g/liter; n = 13) or maltose-dextrin (placebo; n = 13) for 21 days. Mean tumor diameter, measured on day 11, 14, 18, and 21 subsequent to tumor implantation, was 41, 32, 21, and 19% smaller in the pyruvate group (P < 0.05). When euthanized, tumor weight was also smaller in the pyruvate group: pyruvate = 15.0 +/- 2.3 (SEM) g; placebo = 24.9 +/- 3.2 g, P < 0.05. Visual inspection of organs suggested decreased lung metastases with pyruvate feeding (P < 0.05). Upon microscopic evaluation of organs, hepatic tumor was found only in the placebo group. We conclude that pyruvate inhibits implanted tumor growth in rats.

Sero-epidemiological study of severe forms of paralytic poliomyelitis

Poliomyelitis has assumed immense public health importance owing to the magnitude of problem. The present study describes clinical, epidemiological and virological profile of seventy four cases of severe forms of acute paralytic poliomyelitis admitted to Kalawati Saran Children Hospital, New Delhi, during the period from August, 1986 to May, 1987. Thirty two per cent of total paralytic poliomyelitis cases were diagnosed as severe cases. Highest incidence (45.95%) of the cases were in the age group of 6-12 months and male to female ratio was 2.08:1. There was preponderance of cases from urban area. Among all the cases, 12.2% had received three or more doses of oral poliovaccine. Fever and respiratory involvement were the commonest symptoms. Sixty seven patients (90.5%) were virologically or serologically confirmed as an acute poliomyelitis due to any of the three poliovirus type. On follow up of the cases, complete recovery could be seen only in 4.2% of cases with varying degree of residual paralysis in 95.8% cases.