Enhanced transdermal delivery of pranoprofen from the bioadhesive gels

Transdermal delivery of allopurinol-loaded nanostructured lipid carrier in the treatment of gout

BACKGROUND

Allopurinol (ALP), a xanthine oxidase inhibitor, is a first line drug for the treatment of gout and hyperuricemia. Being the member of BCS class II drugs, ALP has solubility problem, which affects its bioavailability. Also, ALP has shorter half-life and showed GI related problems. In present study, ALP was encapsulated in nanostructured lipid carriers (NLCs) to ensure enhanced bioavailability, improved efficacy and safety in vivo.

METHODOLOGY

ALP-loaded NLCs were fabricated by micro-emulsion technique. The prepared NLCs were optimized via design expert in term of particle size, zeta potential and entrapment efficiency. FTIR, PXRD and TEM analysis were carried out to check chemical interaction, polymorphic form and surface morphology of the optimized formulation. ALP-loaded NLCs were then loaded into HPMC based poloxamer-407 gel and were characterized. In vitro and ex vivo analysis were carried out via dialysis membrane method and franz diffusion cell, respectively. Uric acid was used for induction of gout and the anti-gout activity of ALP-loaded NLCs gel was performed and compared with ALP suspension.

RESULTS

The optimized formulation had particles in nano-range (238.13 nm) with suitable zeta potential (-31.5 mV), poly-dispersity index (0.115) and entrapment of 87.24%. FTIR results confirmed absence of chemical interaction among formulation ingredients. XRD indicated amorphous nature of ALP-loaded NLCs, whereas TEM analysis confirmed spherical morphology of nanoparticles. The optimized formulation was successfully loaded in to gel and characterized accordingly. The in vitro release and drug release kinetics models showed sustained release of the drug from ALP-loaded NLCs gel. Furthermore, about 28 fold enhanced permeation was observed from ALP-loaded NLCs gel as compared to conventional gel. Skin irritation study disclosed safety of ALP-loaded NLCs gel for transdermal application. Furthermore, ALP-loaded NLCs gel showed significantly enhanced anti-gout activity in Sprague-Dawley rats after transdermal administration as compared to oral ALP suspension.

CONCLUSION

ALP-loaded NLCs gel after transdermal administration sustained the drug release, avoid gastrointestinal side effects and enhance the anti-gout performance of ALP. It can be concluded, that NLCs have the potential to deliver drugs via transdermal route as indicated in case of allopurinol.

Design and optimization of film-forming gel of etoricoxib using research surface methodology

The present investigation is focused on the development of transdermal film-forming gel (FFG) loaded with etoricoxib employing research surface methodology (RSM). Box-Behnken surface design method was used to develop experimental run using different concentrations of etoricoxib, hydroxypropyl methylcellulose (HPMC K100M), and eudragit RL100 as independent variables, and Derringer's optimization tool was employed to optimize best possible formulation. The dependent variables considered in this study were viscosity and drug permeation at 24 h (Q24, μg/cm²). Anti-inflammatory study was performed on Wistar albino rats for 8 h. Skin irritation studies and accelerated stability studies were performed for validated FFG formulations. Quadratic model was found to be best fit model (p < 0.0001) for both the responses. The influence of HPMC concentration on the viscosity was found to be highest whereas concentration of etoricoxib was maximum for Q24. The optimum composition of the FFG was observed to be 4% of etoricoxib, 1.1246% of HPMC, and 0.4% of eudragit. Above composition resulted in viscosity of 1549.5 mPa.s and maximum Q24 of 4639.11 μg/cm² with desirability 0.918. The in vivo anti-inflammatory study demonstrated better sustained release effect (for 8 h) of optimized FFG compared to orally administered drug suspension. An average irritation score of 0.555 was observed on Draize scoring system. The validated FFG formulation was found to be stable for the 3 months in accelerated conditions. It can be concluded from the above investigations that the validated FFG formulation of etoricoxib is well tolerated and could provide sustained drug release for 8 h. Graphical abstract.

Evaluation of the UVB-screening capacity and restorative effects exerted by farnesol gel on UVB-caused sunburn

Farnesol, a natural 15-carbon organic compound, has various microbiological and cellular activities. It has been found to exert apoptosis-inducing effects against carcinoma cells as well as antiallergic and anti-inflammatory effects in vivo. In the current study, a series of formulations composed of various concentrations of hydroxypropyl methylcellulose (HPMC) with the addition of hyaluronan (HA) and xanthan gum (XG) was designed to evaluate the UVB-screening and H₂ O₂ -eliminating effects of farnesol in normal fibroblasts. Farnesol at 0.005, 0.0075, and 0.01% exhibited significant capacity for H₂ O₂ scavenging; at 0.0025%, it showed insignificant effects. Under 120-min UVB exposure, screening with plural gel composed of 0.0025% farnesol, 0.5% HA, and 0.5% XG containing 1.5% or 2% HPMC retained normal fibroblast viability. After 60-min exposure to UVB, screening with plural gel composed of farnesol, HA, XG, and 0.5%, 1.0%, 1.5%, or 2% HPMC decreased the ratio of the G1 phase and increased ratio of the S phase in comparison with the accumulated cell cycle of the normal fibroblasts without screening. The gel with 2% HPMC displayed the strongest cell cycle-reversal ability. In vivo histopathological results showed that the prepared plural gels with 0.5% or 2% HPMC and farnesol, HA, and XG had greater antiphotoaging and reparative effects against UVB-induced changes and damage in the skin. In conclusion, the current in vitro and in vivo results demonstrated that the prepared plural composed of 0.0025% farnesol, 0.5% HA, 0.5% XG, and 2% HPMC possessed the greatest UVB-screening capacity and the strongest restorative effects on UVB-induced sunburned skin.

Cross-Linked Hydrogel for Pharmaceutical Applications: A Review

Hydrogels are promising biomaterials because of their important qualities such as biocompatibility, biodegradability, hydrophilicity and non-toxicity. These qualities make hydrogels suitable for application in medical and pharmaceutical field. Recently, a tremendous growth of hydrogel application is seen, especially as gel and patch form, in transdermal drug delivery. This review mainly focuses on the types of hydrogels based on cross-linking and; secondly to describe the possible synthesis methods to design hydrogels for different pharmaceutical applications. The synthesis and chemistry of these hydrogels are discussed using specific pharmaceutical examples. The structure and water content in a typical hydrogel have also been discussed.

Design expert assisted formulation of topical bioadhesive gel of sertaconazole nitrate

PURPOSE

The objective of this work was to develop a bioadhesive topical gel of sertaconazole nitrate with the help of response-surface approach.

METHODS

Experiments were performed according to a 3-level factorial design to evaluate the effects of two independent variables [amount of Carbapol 934 = X1) and Sodium carboxymethylcellulose (NaCMC) = X2)] on the bioadhesive character of gel, rheological property of gel (consistency index), and in-vitro drug release. The best model was selected to fit the data.

RESULTS

Mathematical equation was generated by Design Expert® software for the model which assists in determining the effect of independent variables. Response surface plots were also generated by the software for analyzing effect of the independent variables on the response. The effect of formulation variables on the product characteristics can be easily predicted and precisely interpreted by using a 3-level factorial design and generated quadratic mathematical equations.

CONCLUSION

On the basis of product characteristics viscosity, bioadhesiveness, permeation study, in-vitro release, in-vivo studies, TPA and spreadability it can be concluded that the best batch of topical bioadhesive gel of Sertaconazole nitrate would be with 1% Carbopol 934 and 1% NaCMC.

Disposition of drugs in block copolymer micelle delivery systems: from discovery to recovery

Since their discovery in the early 1980s, polymeric micelles have been the subject of several studies as delivery systems that can potentially improve the therapeutic performance and modify the toxicity profile of encapsulated drugs by changing their pharmacokinetic characteristics. The efforts in this area have led in recent years to the advancement of several polymeric micellar formulations to clinical trials, some of which have shown promise in changing the biodistribution of the incorporated drug after intravenous administration as a means of tumour-targeted drug delivery. Recently, the possible benefit of polymeric micellar delivery in enhancing the absorption and bioavailability of incorporated drugs from alternative routes of drug administration has attracted interest. This article provides an overview of the effect of polymeric micellar delivery on absorption, distribution, metabolism and excretion of incorporated therapeutic agents. It also aims to assess the current information on the performance of polymeric micellar delivery systems in modifying the pharmacokinetics/pharmacodynamics of the incorporated drugs in clinical trials, and to re-examine the important structural factors required for successful design of polymeric micellar delivery systems capable of inducing favourable changes in the pharmacokinetics of the encapsulated drug.

Use of topical medication in orofacial neuropathic pain: a retrospective study

OBJECTIVE

The objective of this study was to evaluate the effect of topical medications as a single treatment or in combination with systemic medications in the treatment of orofacial neuropathic pain conditions.

STUDY DESIGN

A retrospective chart review of 39 patients treated for orofacial neuropathic pain at the Orofacial Pain Clinic in the New Jersey Dental School was performed. In line with the treatment selection, the subjects were divided into 3 groups: topical medications only (n = 12), systemic medications only (n = 10), and a combination of both (n = 17).

RESULTS

The starting pain level as expressed in pain Visual Analog Scale for the 3 groups was significantly different. The combined treatment group baseline pain level (7.5 +/- 0.403 SEM; P = .0015) and the systemic treatment only group pain level (8.6 +/- 0.611 SEM; P = .0375) was significantly elevated compared to the topical only group (6.1 +/- 0.716 SEM; P = .1057). Following treatment, pain level was significantly reduced in all 3 groups. The combined group had the highest pain relief (52.0 +/- 6.676 SEM % reduction; P < .0001) followed by the systemic-only group (40.6 +/- 9.727 SEM % reduction; P = .0029) and the topicals-only group (40.9 +/- 10.775 SEM% reduction; P = .0048). The time taken for the topical treatment only to act was significantly shorter (3 weeks +/- 0.479 SEM; P = .0015) when compared with the systemic-only (4 weeks +/- 0.772 SEM; P = .3629) and the combined group (5.5 weeks +/- 0.912 SEM; P = .1738).

CONCLUSION

Topical medication as single treatment or in combination with systemic medications can reduce orofacial neuropathic pain severity. Further prospective research should be performed to validate this treatment option.