Drug delivery is the method or process of administering a pharmaceutical compound to achieve a therapeutic effect in humans or animals. For the treatment of human diseases, nasal and pulmonary routes of drug delivery are gaining increasing importance. These routes provide promising alternatives to parenteral drug delivery particularly for peptide and protein therapeutics. For this purpose, several drug delivery systems have been formulated and are being investigated for nasal and pulmonary delivery. These include liposomes, proliposomes, microspheres, gels, prodrugs, cyclodextrins, among others. Nanoparticles composed of biodegradable polymers show assurance in fulfilling the stringent requirements placed on these delivery systems, such as ability to be transferred into an aerosol, stability against forces generated during aerosolization, biocompatibility, targeting of specific sites or cell populations in the lung, release of the drug in a predetermined manner, and degradation within an acceptable period of time.

Cyclodextrins (CDs) are a family of cyclic oligosaccharides with a hydrophilic outer surface and a lipophilic central cavity. CD molecules are relatively large with a number of hydrogen donors and acceptors and, thus in general, they do not permeate lipophilic membranes. In the pharmaceutical industry, CDs have mainly been used as complexing agents to increase aqueous solubility of poorly soluble drugs and to increase their bioavailability and stability. CDs are used in pharmaceutical applications for numerous purposes, including improving the bioavailability of drugs. Current CD-based therapeutics is described and possible future applications are discussed. CD-containing polymers are reviewed and their use in drug delivery is presented. Of specific interest is the use of CD-containing polymers to provide unique capabilities for the delivery of nucleic acids. Studies in both humans and animals have shown that CDs can be used to improve drug delivery from almost any type of drug formulation. Currently, there are approximately 30 different pharmaceutical products worldwide containing drug/CD complexes in the market.

The development of sound bioanalytical method(s) is of paramount importance during the process of drug discovery and development, culminating in a marketing approval. The objective of this paper is to review the sample preparation of drug in biological matrix and to provide practical approaches for determining selectivity, specificity, limit of detection, lower limit of quantitation, linearity, range, accuracy, precision, recovery, stability, ruggedness, and robustness of liquid chromatographic methods to support pharmacokinetic (PK), toxicokinetic, bioavailability, and bioequivalence studies. Bioanalysis, employed for the quantitative determination of drugs and their metabolites in biological fluids, plays a significant role in the evaluation and interpretation of bioequivalence, PK, and toxicokinetic studies. Selective and sensitive analytical methods for quantitative evaluation of drugs and their metabolites are critical for the successful conduct of pre-clinical and/or biopharmaceutics and clinical pharmacology studies.

Recent years have witnessed the introduction of several high-quality review articles into the literature covering various scientific and technical aspects of bioanalysis. Now it is widely accepted that bioanalysis is an integral part of the pharmacokinetic/pharmacodynamic characterization of a novel chemical entity from the time of its discovery and during various stages of drug development, leading to its market authorization. In this compilation, the important bioanalytical parameters and its application to drug discovery and development approaches are discussed, which will help in the development of safe and more efficacious drugs with reduced development time and cost. It is intended to give some general thoughts in this area which will form basis of a general framework as to how one would approach bioanalysis from inception (i.e., discovery of a lead molecule) and progressing through various stages of drug development.

Introduction:The work was aimed to develop an enteric-coated hydroxypropyl methylcellulose (HPMC) capsules (ECHC) plugged with 5-fluorouracil (5-FU)-loaded microsponges in combination with calcium pectinate beads.Materials and Methods:The modified quasi-emulsion solvent diffusion method was used to prepare microsponges. A 32 factorial design was employed to study the formulation and the effects of independent variables (volume of organic solvent and Eudragit-RS100 content) on dependent variables (particle size, %entrapment efficiency, and %cumulative drug release). The optimized microsponge (F4) was characterized by scanning electron microscopy, powder X-ray diffraction, and thermogravimetric analysis. F4 was plugged along with the calcium pectinate beads in HPMC capsules coated with enteric polymer Eudragit-L100 (Ed-L100) and/or Eudragit-S100 (Ed-S100) in different proportions. An in vitro release study of ECHC was performed in simulated gastric fluid for 2 h, followed by simulated intestinal fluid for next 6 h and then in simulated colonic fluid (in the presence and absence of pectinase enzyme for further 16 h). The optimized formulation was subjected to in vivo roentgenographic and pharmacokinetic studies in New Zealand white rabbits to analyze the in vivo behavior of the developed colon-targeted capsules.Results:Drug release was retarded on coating with Ed-S100 in comparison to a blend of Ed-S100:Ed-L100 coating. The percentage of 5-FU released at the end of 24 h from ECHC3 was 97.83 ± 0.12% in the presence of pectinase whereas in the control study, it was 40.08 ± 0.02%.Conclusion:Thus, enteric-coated HPMC capsules plugged with 5-FU-loaded microsponges and calcium pectinate beads proved to be a promising dosage form for colon targeting.

Introduction Learning one’s HIV status through HIV testing services (HTS) is an essential step toward accessing treatment and linking to preventive services for those at high HIV risk. HTS may impact subsequent sexual behaviour, but the degree to which this varies by population or is true in the setting of contemporary HIV prevention activities is largely unknown. As part of the 2019 World Health Organization Consolidated Guidelines on HTS, we undertook a systematic review and meta‐analysis to determine the effect of HTS on sexual behaviour. Methods We searched nine electronic databases for studies published between July 2010 and December 2019. We included studies that reported on at least one outcome (condom use [defined as the frequency of condom use or condom‐protected sex], number of sex partners, HIV incidence, STI incidence/prevalence). We included studies that prospectively assessed outcomes and that fit into one of three categories: (1) those evaluating more versus less‐intensive HTS, (2) those of populations receiving HTS versus not and (3) those evaluating outcomes after versus before HTS. We conducted meta‐analyses using random‐effects models. Results and discussion Of 29 980 studies screened, 76 studies were included. Thirty‐eight studies were randomized controlled trials, 36 were cohort studies, one was quasi‐experimental and one was a serial cross‐sectional study. There was no significant difference in condom use among individuals receiving more‐intensive HTS compared to less‐intensive HTS (relative risk [RR]=1.03; 95% CI: 0.99 to 1.07). Condom use was significantly higher after receiving HTS compared to before HTS for individuals newly diagnosed with HIV (RR = 1.65; 95% CI: 1.36 to 1.99) and marginally significantly higher for individuals receiving an HIV‐negative diagnosis (RR = 1.63; 95% CI: 1.01 to 2.62). Individuals receiving more‐intensive HTS reported fewer sex partners at follow‐up than those receiving less‐intensive HTS, but the finding was not statistically significant (mean difference = −0.28; 95% CI: −3.66, 3.10). Conclusions Our findings highlight the importance of using limited resources towards HTS strategies that focus on early HIV diagnosis, treatment and prevention services rather than resources dedicated to supplementing or enhancing HTS with additional counselling or other interventions.

The colon is a site where both local and systemic delivery of drugs can take place. Local delivery could, for example, allow topical treatment of inflammatory bowel disease. Treatment could be made more effective if it were possible for drugs to be targeted directly on the colon. Systemic side effects could also be reduced. Colon specific systems might also allow oral administration of peptide and protein drugs, which are normally inactivated in the upper parts of the gastrointestinal tract. Primary approaches for CDDS (Colon Specific Drug Delivery), which includes prodrugs, pH and time dependent systems and microbially triggered drug delivery system achieved limited success and having limitations. Newly developed CDDS, which includes pressure controlled colonic delivery capsules (PCDCS), CODES TM and osmotic controlled drug delivery are unique in terms of achieving in vivo site specificity and feasibility of manufacturing process. This review also focuses on evaluations of CDDS in general.

In designing of Prodrugs, targeting can be achieved in two ways: site-specified drug delivery and site-specific drug bioactivation. Prodrugs can be designed to target specific enzymes or carriers by considering enzyme-substrate specificity or carrier-substrate specificity in order to overcome various undesirable drug properties. There are certain techniques which are used for tumor targeting such as Antibody Directed Enzyme Prodrug Therapy [ADEPT] Gene-Directed Enzyme Prodrug Therapy [GDEPT], Virus Directed Enzyme Prodrug Therapy [VDEPT] and Gene Prodrug Activation Therapy [GPAT]. Our review focuses on the Prodrugs used in site-specific drug delivery system specially on tumor targeting.