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Aerosols encompass a wide range of products and applications ranging from simple topical and toiletry products to inhaled therapeutics for chronic conditions to deliver potent medications for local and systemic actions. The various modes of delivery include pressurized metered-dose inhalers (pMDIs), nebulized systems, and dry-powder inhalation (DPI) systems as well as intranasally delivered products. This chapter gives an account of different aerosolized systems w.r.t. the components, formulation, manufacturing, and characterization. The patient (human) factors to be considered, namely, the patient–device interface, important for successful therapy, and outcomes are also included.

Background: Alginate-based, raft-forming antacid products with reflux suppressant activity are complex formulations expected to achieve effective raft formation and cause elimination or displacement of the acid pocket, which is typically manifested in gastroesophageal reflux disease (GERD).Methods: In the present study, six alginate-based raft-forming products commercially available in the Indian market were compared in terms of their acid neutralization properties, strength, resilience and structural and thermal properties of their rafts. Percent alginate content was also determined.Results: Rafts of products containing calcium-based antacids formed voluminous, porous and floating rafts within seconds of addition to the simulated gastric fluid (SGF) compared with the products that contained aluminium and magnesium-based antacids. Marked differences were not evident in the ANC (acid neutralization capacity) values of the various products. No correlation was observed between ANC and raft-forming capacity or duration of neutralization. Raft structures affected their neutralization profiles. Rafts of porous and absorbent nature could retain their ANC probably due to release of trapped antacids. Further, raft strengths of only two products were above the British Pharmacopoeia specification of not less than 7.5 g. Sodium alginate content was within specifications (85-115%) for three of the six products.Conclusions: Raft-forming formulations with higher alginate content and calcium-based antacids have better physicochemical properties such as ANC, neutralization profiles, raft strength and raft resilience than those with lower alginate content or those containing aluminium or magnesium-based antacids.

The lung is the primary entry site and target for Mycobacterium tuberculosis; more than 80% of the cases reported worldwide are of pulmonary tuberculosis. Hence, direct delivery of anti-tubercular drugs to the lung would be beneficial in reducing both, the dose required, as well as the duration of therapy for pulmonary tuberculosis. In the present study, microsphere-based dry powder inhalation systems of the anti-tubercular drugs, rifampicin and rifabutin, were developed and evaluated, with a view to achieve localized and targeted delivery of these drugs to the lung.The drug-loaded chitosan microparticles were prepared by an ionic gelation method, followed by spray-drying to obtain respirable particles. The microparticles were evaluated for particle size and drug release. The drug-loaded microparticles were then adsorbed onto an inhalable lactose carrier and characterized for in vitro lung deposition on an Andersen Cascade Impactor (ACI) followed by in vitro uptake study in U937 human macrophage cell lines. In vivo toxicity of the developed formulations was evaluated using Sprague Dawley rats.Both rifampicin and rifabutin-loaded microparticles had MMAD close to 5 μm and FPF values of 21.46% and 29.97%, respectively. In vitro release study in simulated lung fluid pH 7.4 showed sustained release for 12 hours for rifampicin microparticles and up to 96 hours for rifabutin microparticles, the release being dependent on both swelling of the polymer and solubility of the drugs in the dissolution medium. In vitro uptake studies in U937 human macrophage cell line suggested that microparticles were internalized within the macrophages. In vivo acute toxicity study of the microparticles in Sprague Dawley rats revealed no significant evidence for local adverse effects.Thus, spray-dried microparticles of the anti-tubercular drugs, rifampicin and rifabutin, could prove to be an improved, targeted, and efficient system for treatment of tuberculosis.

Tuberculosis (TB), a serious infectious disease caused by Mycobacterium tuberculosis , has resulted in more deaths than any other communicable disease, and has caused a lot of problems in the economy and social status of developing countries. Current chemotherapy for TB still relies on drugs discovered way back in the 1960s and is laborious, extensive, and remains extremely complicated to complete in many of the highest burdened regions. The various global strategies like DOTS therapy have not achieved much success, and the Third World is plagued with the development of drug-resistant strains. With difficulties in obtaining novel anti-TB drug candidates in the development pipeline, it is important to look into the existing drugs and develop novel and targeted delivery systems of these drugs, to overcome the drawbacks of current conventional formulations. Nanoparticle (NP) technology offers an attractive and promising approach to take the existing chemotherapies and deliver them more efficaciously, reducing the dosing frequency and duration of treatment, as well as increased bioavailability. In addition, it is possible to functionalize the NPs with specific ligands and achieve active targeting to the Mycobacterium -infested tissues, especially the alveolar macrophages. This advance can help achieve quicker cures, with lower doses, improved patient adherence, and overall reduce medication burden; all of which can help curb the development of drug resistance. Further, several nanotechnology-based vaccines as an alternative to the current bacilli Calmette–Guerin vaccine for prevention of TB are also promising approaches being investigated. This chapter will provide an insight into the nanotechnology approaches for chemotherapy and prophylaxis of TB, and highlight the challenges in implementation of these technologies.

Objective: To compare the bioavailability of two brands of phenytoin sodium tablets available in the Indian market using Eptoin TM as the reference. Materials and Methods: A randomized, assessor-blind, three-way crossover design study was carried out over a period of 6 months after approval from the Institutional Review Board (IRB). Twenty-two healthy male participants received a single oral 300 mg oral tablet of either of the formulations with a 2-week washout. Blood samples were collected predose and at regular intervals postdose. Plasma phenytoin levels were estimated by high-performance liquid chromatography. Calculation of C max , AUC 0-t , and AUC 0-∞ was done by the linear trapezoidal rule and 90-110% margin (90% confidence interval (CI)) was used to assess bioequivalence. Results: Twenty volunteers completed the study. It was seen that the log-transformed values of C max , AUC 0-t , and AUC 0-∞ of the test formulations were not within the specified limits. Conclusion: Bioinequivalence of available phenytoin brands indicates that switching brands could lead to variations in blood concentrations and thus impact safety and efficacy. If a brand switch is done for any reason, stringent drug-level monitoring is advised.