Physicochemical properties and antifungal activity of amphotericin B incorporated in cholesteryl carbonate esters

A Critical Review on Emerging Trends in Dry Powder Inhaler Formulation for the Treatment of Pulmonary Aspergillosis

Pulmonary aspergillosis (PA), a pulmonary fungal infection caused by Aspergillus spp., is a concern for immunocompromised populations. Despite substantial research efforts, conventional treatments of PA using antifungal agents are associated with limitations such as excessive systemic exposure, serious side effects and limited availability of the therapeutics in the lungs for an adequate duration. To overcome the limitations associated with the conventional regimens, pulmonary delivery of antifungal agents has become a focal point of research because of the superiority of local and targeted drug delivery. Dry powder inhalers and nebulized formulations of antifungal agents have been developed and evaluated for their capability to effectively deliver antifungal agents to the lungs. Moreover, progress in nanotechnology and the utilization of nanocarriers in the development of pulmonary delivery formulations has allowed further augmentation of treatment capability and efficiency. Thus, the following review provides an insight into the advantages and therapeutic potential of the utilization of nanocarriers in pulmonary delivery of antifungal agents for the treatment of PA. In addition, discussions on formulation aspects and safety concerns together with the clinical and regulatory aspects of the formulations are presented, which suggest the possibility and desirability of utilization of nanocarriers in the treatment of PA.

Thermoresponsive gating membranes embedded with liquid crystal(s) for pulsatile transdermal drug delivery: An overview and perspectives

Due to the circadian rhythm regulation of almost every biological process in the human body, physiological and biochemical conditions vary considerably over the course of a 24-h period. Thus, optimal drug delivery and therapy should be effectively controlled to achieve the desired therapeutic plasma concentrations and therapeutic drug responses at the required time according to chronopharmacological concepts, rather than continuous maintenance of constant drug concentrations for an extended time period. For many drugs, it is not always necessary to constantly deliver a drug into the human body under disease conditions due to rhythmic variations. Pulsatile drug delivery systems (PDDSs) have been receiving more attention in pharmaceutical development by providing a predetermined lag period, followed by a fast or rate-controlled drug release after application. PDDSs are characterized by a programmed drug release, which may release a drug at repeatable pulses to match the biological and clinical needs of a given disease therapy. This review article focuses on thermoresponsive gating membranes embedded with liquid crystals (LCs) for transdermal drug delivery using PDDS technology. In addition, the principal rationale and the advanced approaches for the use of PDDSs, the marketed products of chronotherapeutic DDSs with pulsatile function designed by various PDDS technologies, pulsatile drug delivery designed with thermoresponsive polymers, challenges and opportunities of transdermal drug delivery, and novel approaches of LC systems for drug delivery are reviewed and discussed. A brief overview of all academic research articles concerning single LC- or binary LC-embedded thermoresponsive membranes with a switchable on-off permeation function through topical application by an external temperature control, which may modulate the dosing interval and administration time according to the therapeutic needs of the human body, is also compiled and presented. In the near future, since thermal-based approaches have become a well-accepted method to enhance transdermal delivery of different water-soluble drugs and macromolecules, a combination of the thermal-assisted approach with thermoresponsive LCs membranes will have the potential to improve PDDS applications but still poses a great challenge.

Long-term sustained-released in situ gels of a water-insoluble drug amphotericin B for mycotic arthritis intra-articular administration: preparation, in vitro and in vivo evaluation

Amphotericin B (AMB) was often used in intra-articular injection administration for fungal arthritis, because it could often bring a satisfactory therapeutic efficacy and a minimum systemic toxic side effect. However, because of the multiple operations and the frequent injections, the compliance of the patients was bad. Therefore, to develop a long-term sustained-released preparation of AMB for mycotic arthritis intra-articular administration is of great significance. The purpose of present study was to develop a long-term sustained-released in situ gel of a water-insoluble drug AMB for mycotic arthritis intra-articular administration. Based on the evaluations of the in vitro properties of the formulations, the formulation containing 10% (w/w) ethanol, 15% (w/w) PG, 0.75% (w/w) HA, 5% (w/w) purified soybean oil, 0.03% (w/w) α-tocopherol, 15% (w/w) water and 55% (w/w) glyceryl monooleate was selected as a suitable intra-articular injectable in situ gel drug delivery system for water-insoluble drug AMB. Furthermore, the results of the in vivo study on rabbits showed that the selected formulation was a safe and effective long-term sustained-released intra-articular injectable AMB preparation. Therefore, the presented in situ AMB gel could reduce the frequency of the administration in the AMB treatment of fungal arthritis, and then would get a good patient compliance.

Clinical experimentation with aerosol antibiotics: current and future methods of administration

Currently almost all antibiotics are administered by the intravenous route. Since several systems and situations require more efficient methods of administration, investigation and experimentation in drug design has produced local treatment modalities. Administration of antibiotics in aerosol form is one of the treatment methods of increasing interest. As the field of drug nanotechnology grows, new molecules have been produced and combined with aerosol production systems. In the current review, we discuss the efficiency of aerosol antibiotic studies along with aerosol production systems. The different parts of the aerosol antibiotic methodology are presented. Additionally, information regarding the drug molecules used is presented and future applications of this method are discussed.

New insights in the production of aerosol antibiotics. Evaluation of the optimal aerosol production system for ampicillin-sulbactam, meropenem, ceftazidime, cefepime and piperacillin-tazobactam

BACKGROUND

Several aerosol antibiotics are on the market and several others are currently being evaluated. Aim of the study was to evaluate the aerosol droplet size of five different antibiotics for future evaluation as an aerosol administration.

MATERIALS AND METHODS

The nebulizers Sunmist(®), Maxineb(®) and Invacare(®) were used in combination with four different "small <6 ml" residual cups and two "large <10 ml" with different loadings 2-4-6-8 ml (8 ml only for large residual cups) with five different antibiotic drugs (ampicilln-sulbactam, meropenem, ceftazidime, cefepime and piperacillin-tazobactam). The Mastersizer 2000 (Malvern) was used to evaluate the produced droplet size from each combination

RESULTS

Significant effect on the droplet size produced the different antibiotic (F=96.657, p<0.001) and the residual cup design (F=68.535, p<0.001) but not the different loading amount (p=0.127) and the nebulizer (p=0.715). Interactions effects were found significant only between antibiotic and residual cup (F=16.736, p<0.001). No second order interactions were found statistically significant.

CONCLUSION

Our results firstly indicate us indirectly that the chemical formulation of the drug is the main factor affecting the produced droplet size and secondly but closely the residual cup design.

Physicochemical performances of indomethacin in cholesteryl cetyl carbonate liquid crystal as a transdermal dosage

A transdermal formulation of indomethacin (IMC) was developed by incorporation into cholesteryl cetyl carbonate (CCC). The liquid crystalline phase properties of the IMC-CCC mixture were detected by polarized light microscopy and differential scanning calorimetry. A low drug loading was obtained (1-5 %) similar to that used in conventional topical IMC in a clinical setting. A controlled release of IMC was found over 12 h. A low amount of IMC in 1 % IMC-CCC permeated the stratum corneum. Further formulation development has been carried out by the addition of lauryl alcohol into 5 % IMC-CCC mixture it was found that the permeation of IMC was significantly improved to 45 % within 24 h.