Development of a novel microemulsion for oral absorption enhancement of all-trans retinoic acid

Thirapit Subongkot,1 Tanasait Ngawhirunpat2 1Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Burapha University, Chonburi, Thailand; 2Department of Pharmaceutical Technology, Faculty of Pharmacy, Silpakorn University, Nakhon Pathom, Thailand Abstract: This study was aimed to develop a novel microemulsion that contained oleth-5 as a surfactant to enhance the oral absorption of all-trans retinoic acid (ATRA). The prepared microemulsion was evaluated for its particle size, shape, zeta potential, in vitro release, in vitro intestinal absorption, intestinal membrane cytotoxicity and stability. The obtained microemulsion was spherical in shape with a particle size of <200 nm and a negative surface charge. The in vitro release of the ATRA-loaded microemulsion was best fit with the zero-order model. This microemulsion significantly improved the intestinal absorption of ATRA. Confocal laser scanning microscopy analysis using a fluorescent dye-loaded microemulsion also confirmed the intestinal absorption result. The intestinal membrane cytotoxicity of the ATRA-loaded microemulsion did not differ from an edible oil (fish oil). Stability testing showed that the ATRA-loaded microemulsion was more stable at 25°C than 40°C. Keywords: microemulsion, all-trans retinoic acid, oral absorption enhancement, oleth-5, fish oi

Effect of liposomal fluidity on skin permeation of sodium fluorescein entrapped in liposomes

Thirapit Subongkot,1 Tanasait Ngawhirunpat21Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Burapha University, Chonburi, Thailand; 2Department of Pharmaceutical Technology, Faculty of Pharmacy, Silpakorn University, Nakhon Pathom, ThailandAbstract: The purpose of this study was to investigate the effect of ultradeformable liposome components, Tween 20 and terpenes, on vesicle fluidity. The fluidity was evaluated by electron spin resonance spectroscopy using 5-doxyl stearic acid and 16-doxyl stearic acid as spin labels for phospholipid bilayer fluidity at the C5 atom of the acyl chain near the polar head group (hydrophilic region) and the C16 atom of the acyl chain (lipophilic region), respectively. The electron spin resonance study revealed that Tween 20 increased the fluidity at the C5 atom of the acyl chain, whereas terpenes increased the fluidity at the C16 atom of the acyl chain of the phospholipid bilayer. The increase in liposomal fluidity resulted in the increased skin penetration of sodium fluorescein. Confocal laser scanning microscopy showed that ultradeformable liposomes with terpenes increase the skin penetration of sodium fluorescein by enhancing hair follicle penetration.Keywords: ultradeformable liposomes, terpenes, fluidity, electron spin resonance spectroscopy, confocal laser scanning microscop

Effect of Limonene and 1,8 Cineole on the Skin Penetration of Fluorescein Sodium Deformable Liposomes

The aim of this study was to develop fluorescein sodium (NaFl) deformable liposomes with two different terpenes, d-limonene and 1,8 cineole, as skin penetration enhancer. NaFl was used as the model drug as it is a hydrophilic diagnostic agent, and has low skin penetration. The liposomes were prepared by reverse phase evaporation method. Their particle size, surface charge, and shape were characterized, in vitro skin penetration of NaFl through porcine skin were investigated. The obtained deformable liposomes were small particle size (&lt;100 nm), negative charge and spherical shape. The liposome containing d-limonene provided the highest amount of NaFl followed by deformable liposomes with 1,8 cineole and conventional liposomes, repectively. The enhancement ratio of formulations containing terpenes were about 18-38fold compared with the conventional liposomes. These results indicated that the obtained deformable liposomes could be used as transdermal delivery of NaFl and incorporation of terpenes into deformable liposomes provided high efficiency for NaFl delivery through the skin.</jats:p

Hospitalization and cost after switching from atypical to typical antipsychotics in schizophrenia patients in Thailand

Tuanthon Boonlue,1,2 Suphat Subongkot,1,2 Piyameth Dilokthornsakul,3,4 Ronnachai Kongsakon,5 Oraluck Pattanaprateep,6 Orabhorn Suanchang,7 Nathorn Chaiyakunapruk3,8&ndash;10 1Clinical Pharmacy Division, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen, Thailand; 2The College of Pharmacotherapy of Thailand, Nonthaburi, Thailand; 3Center of Pharmaceutical Outcomes Research, Department of Pharmacy Practice, Faculty of Pharmaceutical Sciences, Naresuan University, Phitsanulok, Thailand; 4Center for Pharmaceutical Outcomes Research, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO, USA; 5Department of Psychiatry, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand; 6Department of Health Informatics, Ramathibodi Hospital, Mahidol University, 7Department of Pharmacy, Somdet Chaopraya Institute of Psychiatry, Bangkok, Thailand; 8School of Pharmacy, Monash University Malaysia, Selangor, Malaysia; 9School of Population Health, University of Queensland, Brisbane, Australia; 10School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA Background: Several clinical practice guidelines suggest using atypical over typical antipsychotics in patients diagnosed with schizophrenia. Nevertheless, cost-containment policy urged restricting usage of atypical antipsychotics and switching from atypical to typical antipsychotics. Objective: This study aimed to evaluate clinical and economic impacts of switching from atypical to typical antipsychotics in schizophrenia patients in Thailand. Methods: From October 2010 through September 2013, a retrospective cohort study was performed utilizing electronic database of two tertiary hospitals. Schizophrenia patients aged 18 years or older and being treated with atypical antipsychotics were included. Patients were classified as atypical antipsychotic switching group if they switched to typical antipsychotics after 180 days of continual atypical antipsychotics therapy. Outcomes were schizophrenia-related hospitalization and total health care cost. Logistic and Poisson regression were used to evaluate the risk of hospitalization, and generalized linear model with gamma distribution was used to determine the health care cost. All analyses were adjusted by employing propensity score and multivariable analyses. All cost estimates were adjusted according to 2013 consumer price index and converted to US$at an exchange rate of 32.85 Thai bahts/US$. Results: A total of 2,354 patients were included. Of them, 166 (7.1%) patients switched to typical antipsychotics. The adjusted odds ratio for schizophrenia-related hospitalization in atypical antipsychotic switching group was 1.87 (95% confidence interval [CI] 1.23&ndash;2.83). The adjusted incidence rate ratio was 2.44 (95% CI 1.57&ndash;3.79) for schizophrenia-related hospitalizations. The average total health care cost was lower in patients with antipsychotic switching (&ndash;$64; 95$459 to $332). Conclusion: Switching from atypical to typical antipsychotics is associated with an increased risk of schizophrenia-related hospitalization. Nonetheless, association with average total health care cost was not observed. These findings can be of use as a part of evidence in executing prospective cost-containment policy. Keywords: antipsychotic switching, schizophrenia, hospitalization, cost, atypical antipsychotics, typical antipsychotic

Etodolac transdermal cubosomes for the treatment of rheumatoid arthritis: ex vivo permeation and in vivo pharmacokinetic studies

Journal Drug Delivery Volume 24, 2017 - Issue 1In this study, transdermal etodolac-loaded cubosomes were developed in order to relieve patient pain and joints stiffness by providing stable etodolac concentration at the targeting sites through controlled drug delivery via the noninvasive skin route with more sustaining and less frequent dosing. Different ratios and percentages of poloxamer 407 and monoolein were used to formulate the cubosomes using emulsification and homogenization processes. The etodolac-loaded cubosomes showed particle size values ranging from 135.95 to 288.35 nm and zeta potential values ranging from −18.40 to −36.10 mV. All the cubosomes offered an encapsulation efficiency value of about 100% and showed drug loading capacity ranging from 1.28 to 6.09%. The in vitro drug release studies revealed a controlled drug release profile with a drug release rate up to 15.08%/h. Increasing poloxamer concentration in etodolac-loaded cubosomes resulted in nanoparticles with less particle size and faster drug release. The particles exhibited cubic and hexagonal shapes. The DSC and X-ray analysis demonstrated that the drug was encapsulated in the cubosomes bicontinuous structures in amorphous form. In addition, investigated cubosomes exhibited fast drug penetration through excited mice skin followed by slower drug penetration for up to 24 h. The pharmacokinetic study in human volunteers showed that the selected etodolac-loaded cubosomes enhanced the bioavailability of etodolac as compared to the oral capsules (266.11%) with evidence of longer half-life and higher MRT that reached 18.86 and 29.55 h, respectively. The etodolac-loaded cubosomes propose a promising system for treatment of arthritis simply through skin application