The role of pituitary adenylyl cyclase-activating polypeptide in the motivational effects of addictive drugs.

Pituitary adenylyl cyclase activating polypeptide (PACAP) was originally isolated from the hypothalamus and found to stimulate adenylyl cyclase in the pituitary. Later studies showed that this peptide and its receptors (PAC1, VPAC1, and VPAC2) are widely expressed in the central nervous system (CNS). Consistent with its distribution in the CNS, the PACAP/PAC1 receptor system is involved in several physiological responses, such as mediation of the stress response, modulation of nociception, regulation of prolactin release, food intake, etc. This system is also implicated in different pathological states, e.g., affective component of nociceptive processing, anxiety, depression, schizophrenia, and post-traumatic stress disorders. A review of the literature on PubMed revealed that PACAP and its receptors also play a significant role in the actions of addictive drugs. The goal of this review is to discuss the literature regarding the involvements of PACAP and its receptors in the motivational effects of addictive drugs. We particularly focus on the role of this peptide in the motivational effects of morphine, alcohol, nicotine, amphetamine, methamphetamine, and cocaine. This article is part of the special issue on Neuropeptides.

Formulation development and characterization of cefazolin nanoparticles-loaded cross-linked films of sodium alginate and pectin as wound dressings.

The present study focuses on the preparation of nanoparticles-loaded ionic cross-linked films for the topical delivery of cefazolin. The aim of the study was to prepare a dosage form which can provide local effect of cefazolin along with sustained delivery at the site of application. Cefazolin was loaded into chitosan nanoparticles to mask the burst release of the drug and they were optimized based on particle size, PDI, % EE and zeta potential. Finally, the prepared nanoparticles were loaded into the films comprising of sodium alginate and pectin which were then subjected to cross-linking via calcium chloride to improve the mechanical strength of the hydrogel films upon exposure to wound fluid. The films were assessed for physical and mechanical properties, swelling behavior, water transmission rate, mucoadhesion, FTIR, DSC, percent inhibition assay and in vitro release profile. Optimized formulation with Cefazolin nanoparticles in the size range of 227 nm and 0.5% CL films showed significantly better results (p < 0.05) as compared to the films with increased cross-linker concentration. Therefore, 0.5% CL films were considered more suitable for the treatment of infections when applied as wound dressing.