Pharmaceuticals and Personal Care Products (PPCPs) disposal practices in Tokha, Nepal: a health belief model study

Abstract

Background

Unused and expired Pharmaceuticals and Personal Care Products (PPCPs) are emerging environmental contaminants that may pose serious risks to human health and the environment. In Nepal, household and pharmacy level waste disposal behaviors remain poorly documented.

Methods

A cross-sectional survey was conducted in Tokha municipality among 298 households and 53 pharmacy retailers. Structured questionnaires included data on: (i) demographic features, (ii) usage and storage patterns of PPCPs, and (iii) their disposal practices. This study was based on the Health Belief Model (HBM) constructs. Data were analyzed using descriptive statistics, chi-square tests, Spearman’s correlation analysis, and partial least squares structural equation modeling (PLS-SEM).

Results

Unsafe storage and improper disposal practices being common among households and pharmacy retailers. About 41.6% of the households stored unused or expired pharmaceuticals, primarily analgesics and skincare products that accounted 63.1% and 77.5%, respectively. Expired PPCPs were mostly disposed of in household garbage containers (88.9%) or burned (12.8%), while only 4.7% were returned to pharmacies. Of the HBM constructs, self-efficacy was the strongest predictor of response to cues for safe disposal behaviors (β = 0.184). Of all pharmacy retailers, only 17% were aware of disposal regulations and facilities. Major challenges included the lack of take-back systems (37.8%) and limited disposal facilities (24.5%). The study highlighted significant challenges in the management of unused and expired PPCPs among households and pharmacy retailers in Tokha municipality.

Conclusions

Households and pharmacy retailers reported unsatisfactory waste disposal practices. Community-based awareness drives and pharmaceutical waste management modules boost self-efficacy by giving people the knowledge and confidence to safely handle and manage unused and expired PPCPs. In a case there are accessible municipal collection systems, pharmacy- or municipal-level take-back points, and clear regulatory mechanisms in the country, it becomes easier for individuals to accelerate that confidence into safety practices to reduce environmental deterioration and protect public health in Nepal.

Supplementary Information

The online version contains supplementary material available at https://doi.org/10.1186/s12889-026-28344-7.

Introduction

Pharmaceuticals and Personal Care Products (PPCPs)

The term Pharmaceuticals and Personal Care Products (PPCPs) was firstly introduced to collectively represent pharmaceuticals, veterinary medicines, and ingredients found in foods, cosmetics, and other personal care products, along with their metabolites [1]. According to the U.S. Environmental Protection Agency [2], PPCPs are defined as “any product used by individuals for personal health or cosmetic purposes or by agribusiness to enhance the growth or health of livestock.” Pharmaceuticals are primarily used for the prevention and treatment of disease in humans as well as animals, whereas personal care products are used for different purposes such as beautification, grooming, and personal hygiene [3].

PPCPs are very difficult to monitor, analyze, and remove due to their complex chemical structures, stability, and diverse physical and chemical properties [4]. They have medium polarity and low to semi-volatile properties, indicating that they are thermally unstable. Due to these characteristics, PPCPs are mainly found in water and soil, and rarely in air [5]. Residues of the most PPCPs are highly soluble in water and remain in the aqueous phase, while less soluble ingredients tend to be associated with solid substances in wastewater. In addition, they may show acidic or alkaline characteristics [3]. Their residues can even migrate into atmosphere, aquatic and terrestrial ecosystem and their environmental distribution is affected by both: physicochemical properties and climate [6]. Their mobility is also influenced by adsorption behavior in biotic and abiotic systems [3].

Of all methods that are used to remove PPCPs from the nature, adsorption is a widely used and effective physical method for removing trace pollutants from water [7]. Degradation of PPCPs can take place through three processes, namely biological, chemical, and physical. Biological methods are nature friendly, cost-effective, and energy-efficient. In the presence of air, microorganisms can degrade most PPCPs, except highly hydrophobic compounds [8]. Chemical degradation involves oxidation, hydrolysis, and advanced oxidation processes (AOPs). AOPs degrade pharmaceuticals by generating strong free radicals in the presence of light, heat, pressure, or the presence of catalysts, breaking down complex molecules into smaller, less harmful substances [9]. Degradation driven by sunlight and UV radiation is another method that breakdown PPCP in surface waters, leading to partial or complete degradation [10]. Although some pharmaceuticals degrade naturally, their continuous usage and release result in regular replenishment, making them “pseudo-persistent” [3]. Consequently, they may show greater persistence in the environment than other organic contaminants, such as chemical pesticides [11].

Environmental and public health concerns of PPCPs

Although PPCPs have been widely used, they have only recently been recognized as emerging environmental contaminants, with traces of their detected residues in surface and groundwater globally [12]. A recent study conducted in China have reported the presence of PPCPs across different water sources at concentrations ranging from 0.2 to 2437.9 ng/L [13]. PPCPs can enter the environment at various stages: (i) production, (ii) usage, and (iii) disposal, either directly or indirectly through wastewater discharges, human and animal waste, or landfill disposal sites [11].

Globally, several PPCPs are produced in large quantities and are designed to force specific physiological processes. Although important, limited research has been conducted so far on their environmental occurrence, distribution and potential ecological risks [12]. Unwanted, unused, or expired medicines are often stored in households for a long duration and their residues may enter the environment through multiple pathways. These include excretion after ingestion, contaminated injection needles, or infusion; removal of topical medicines during bathing and washing; and improper disposal of hospital wastes [14, 15]. Consequently, most expired or unused medicines eventually reach municipal landfills and wastewater treatment plants through solid waste and sewage systems, respectively. In general, unused and expired medicines are improperly disposed, posing significant risks to both human health and the environment [16]. Similar practices can lead to serious consequences, including accidental poisoning in children, adverse effects on flora and fauna, and the emergence of drug-resistant microorganisms [15].

Global, regional, and national distribution of PPCPs in different matrices

Worldwide use of PPCPs has increased alarmingly, leading to a growing number of studies examining the types and quantities of unused pharmaceuticals stored in pharmacies and their disposal behaviors [15]. The most common disposal method of unused and expired medicines is discarding them in domestic waste, which ultimately ends up in municipal landfills. This practice has been widely reported in studies emerging from African countries such as Ghana and Ethiopia [17, 18], highlighting the need for formal education and training programs on sustainable waste disposal methods [19–22]. Factors such as illiteracy, the presence of chronic diseases, and perceived barriers on proper disposal methods have been identified as major factors of inappropriate disposal practices [23].

In S -Asia, improper disposal of pharmaceuticals has become a serious concern [24]. Evidence from India, Afghanistan, Pakistan, Sri Lanka, and Bangladesh indicates that the disposal of unused and expired medicines improperly typically occurs through household waste, sinks, or toilets. There is a negligible involvement of pharmacies or healthcare providers in raising awareness about proper disposal methods, aiming to keep active ingredients out of water and soil ecosystems [25–27]. The best methods could be: (i) take-back programs, (ii) mail-back envelops, (iii) permanent collection kiosks, (iv) incineration, (v) encapsulation, (vi) chemical degradation, and (vii) site-specific treatment plants. Weak healthcare regulatory mechanisms, poor public awareness, and limited involvement from government sectors and pharmaceutical companies have contributed to the unsafe disposal practices, posing a hazardous threat to ecosystems [26].

In Nepal, research focusing on PPCP waste management remains scarce. A study conducted in private pharmacies in Gandaki Province found that community pharmacists in the Kaski district lacked sufficient knowledge and appropriate practices for their waste management [28]. Similarly, studies among medical and dental students from medical colleges in Nepal highlighted the urgent need for advanced knowledge regarding the proper disposal of unused, unwanted, and expired medicines [29, 30]. A recent study in Kathmandu city revealed that although education influenced knowledge and shaped attitudes of residents, most individuals continued to dispose of unused and expired medicines improperly, indicating the urgency of public awareness and unused medicine take-back systems [31].

Theoretical framework of the Health Belief Model (HBM)

Knowledge, attitudes, and behaviors play a crucial role in determining how individuals and pharmacy retailers (PRs) manage and dispose of unused and expired PPCPs. Among several theories explaining a behavior change, the HBM is a widely used psychological framework for understanding individuals’ health-related safety behaviors [32–36]. It has been recognized as an effective model for predicting behavior change and preventive actions, particularly those influenced by perceived threat.

The constructs of HBM are: (i) perceived susceptibility, (ii) perceived severity, (iii) perceived benefits, (iv) perceived barrier, (v) self-efficacy, and (vi) cue-to-action. In this study, perceived susceptibility refers to an individual’s belief about the likelihood of experiencing a health risk due to the improper disposal of PPCPs. Likewise, perceived severity refers to individual’s understanding of the seriousness of a condition and its potential consequences due to the improper disposal of PPCPs. Perceived benefits refer to the belief in the effectiveness of specific actions to minimize risk of improper disposal of PPCPs. Perceived barriers refer to individual’s obstacles or hurdles that may prevent an individual from adopting a proper disposal of PPCPs. Self-efficacy refers to an individual’s self-confidence in their ability to successfully adopt a specific behavior. Finally, cues to action are internal or external triggers that facilitate individuals to change their disposal behavior. For this study, the HBM was selected as it properly explains the psychological factors influencing individuals’ behaviors related to the management of unused and expired PPCPs. Additionally, it helps to identify the major motivations and barriers associated with safe disposal practices.

Research gap and rationale

Although several studies on pharmaceutical waste management have been conducted globally, including in Nepal, most have focused on hospitals and pharmacies, leaving household-level management of PPCPs largely unexplored. Therefore, a significant research gap remains in understanding how household individuals (HHs) manage unused and expired PPCPs. HHs often lack access to proper disposal systems and adequate government support, making them a major source of improper disposal practices that contribute to environmental degradation as well as public health exposures and risks.

With the alarming consumption of PPCPs in municipalities, it is essential to assess practices of both, HHs and PRs to inform policy makers, raise public awareness, and promote safe and sustainable pharmaceutical waste management. Therefore, this study aims to address this gap by examining the knowledge, attitudes, and behaviors of HHs regarding the disposal of unused and expired PPCPs. In addition, the study explores the types of PPCPs frequently reported in the study area and evaluates the challenges faced by HHs and PRs in managing unused and expired PPCPs.

Materials and methods

Study area

This study study was conducted in Tokha municipality, located in the northern part of Kathmandu district, Nepal (Fig. 1). The municipality covers an area of 17.11 km² and has a population of 133,755. The municipality is bordered by Budhanilkantha municipality to the east, Tarakeshwor municipality to the west, Nuwakot district to the north, and Kathmandu Metropolitan City to the south. It includes one provincial hospital, four health posts, six health centers, and one urban health center, providing necessary healthcare facilities [37]. The population of the Tokha municipality has increased from 99,032 in 2011 to 133,755 in 2021, indicating an annual growth rate of 2.88% [38].

Fig. 1.

Location of the study area. (a) Nepal, (b) Kathmandu district, and (c) Tokha municipality showing sampled households (blue circles) and pharmacy retailers (red squares)

Study design

This study was conducted in 2025 using a descriptive and quantitative cross-sectional design. Data were collected through 2 structured questionnaire surveys targeting: (i) household individuals and (ii) pharmacy retailers.

Of the 11 wards of Tokha municipality, Wards 1, 2, 3, and 8 were purposively selected based on their diverse characteristics, including variations in population density, gender composition, urban as well as peri-urban settings, and access to hospitals, healthcare facilities and pharmacies. These characteristics were considered important for examining the knowledge, attitudes, and behaviors of household individuals and pharmacy retailers regarding the pharmaceutical waste management.

Survey

Household individuals (HHs)

The household sample size (n = 298) was determined using the single proportion formula, n = [Z² × P × (1-P)] / e² [23, 29, 39, 40], assuming a proportion (p) of 50%, a margin of error of 8%, and a 95% confidence interval.

where,

To avoid the underestimation of sample size, the calculated sample size was multiplied by a design effect of 2 to account for variation due to clustering. In this study, clustering was done to classify individuals into different clusters according to their accessibility to pharmacies, waste collection centers, and governmental health centers. To ensure fair representation, the total sample was then proportionally allocated among Wards 1, 2, 3, and 8, resulting in sample sizes of 28, 31, 135, and 104 households, respectively. We distributed the total sample size (n = 298) across wards based on each ward’s share of the total population.

A systematic random sampling technique was employed. The sampling frame was based on 2 minimum requirements: (i) the house had to display municipal house number plate showing the house number as well as house owner details, and (ii) at least 1 household member aged ≥ 18 years had to be present and available to participate in the survey. The first household was selected randomly, and subsequently, every fourth household was included in the survey. If a selected household was unavailable or declined to participate, the next immediate household was approached based on our systematic random selection list.

The primary respondent was an adult (≥ 18 years) responsible for purchasing, storing, and managing PPCPs and capable of providing reliable information. In case of multiple eligible members, the priority was given for the household head or older-aged member. In households where PPCPs were used by multiple persons and no single individual was responsible for their management, preference was given to the person who had most recently used PPCPs and could provide the most accurate information. Data were collected through face-to-face interviews using a printed structured questionnaire. Before data collection, the purpose of the study was clearly explained to all respondents, giving them a right to withdraw from the interview at any time.

Pharmacy retailers (PRs)

A parallel survey of PRs was conducted in the same wards as the household survey. A total of 53 PRs were included in this study. Unlike the household survey, no formal sample size calculation was performed due to the limited number of pharmacies on the way to the household survey. Only pharmacies situated along the route to the selected households were included in the survey.

Four criteria were applied to select the PRs: (i) they were encountered during the survey, (ii) they had been operating within the selected wards for > 1 year, (iii) an owner or responsible staff member was present at the time of data collection, and (iv) they consented to participate. Pharmacies that were closed during the survey period were excluded from this survey. The primary respondents were either the owner or a permanent staff member. Data were collected through face-to-face interviews using a structured questionnaire.

Questionnaire development

The questionnaires for both surveys (HHs and PRs) were developed based on a review of recent literature [41–44]. Major variables were identified from past studies [45–47], and the questions were adhered with the study objectives and the local scenarios. In addition, relevant questions were self-developed by the researchers to capture site-specific behaviors. The research committee of Progressive Sustainable Developers Nepal reviewed and certified the survey questionnaire for accuracy and content validity.

The development of the questionnaires and the major literature sources are presented in Table S1. Prior to the main survey, both questionnaires were pre-tested through a pilot study conducted in the neighboring village- Shital Basti Marg (Dhapasi) involving 5% of the total sample (15 households and 6 pharmacy retailers) to assess consistency, completeness, clarity, and accuracy. Data obtained from the pilot study conducted in the neighboring village of different ward were excluded from the main survey to prevent contamination. Based on findings from the pilot survey, minor edits were made before conducting the actual survey.

The survey of HHs (supplementary information, Q1) consisted of 5 sections. Section I included demographic information, while Section II addressed the usage and storage of PPCPs. Section III focused on the 6 constructs of the Health Belief Model and the data collection was performed based on a five-point Likert scale. Section IV examined disposal practices of unused and expired PPCPs, and Section V collected respondents’ feedbacks and suggestions for improving pharmaceutical waste management.

The survey of PRs (supplementary information, Q2) consisted of 6 sections. Section I included retailers’ general information, and Section II addressed their storage practices. Section III focused on disposal practices, while Section IV assessed knowledge and attitudes related to the unused and expired PPCPs. Section V collected information on frequently sold-out or demanded PPCPs, and Section VI gathered suggestions from PRs. Both survey questionnaires included single-choice, multiple-choice, and dichotomous response formats.

Ethical Considerations

Ethical approval was obtained from the Ethical Board of Progressive Sustainable Developers Nepal (PSD-Nepal). Participation in both surveys was voluntary and anonymous. Verbal informed consent was obtained from all respondents prior to survey. A dual recall method that combined 24-hour and 3–6-month was applied to gather both recent and habitual behaviors, thereby minimizing recall bias. Respondents were clearly informed that the survey was for research purpose only, and the privacy of their responses has been strictly maintained.

Data management and coding

Data from both surveys (HHs and PRs) were entered into Microsoft Excel. Missing values were identified and handled using mean substitution [48]. Dichotomous variables were coded as 1 = yes and 0 = no. For multiple-choice questions, each response option was treated as a separate variable, where 1 = yes and 0 = no. For single-choice questions, responses were coded using predefined numerals specified in the questionnaire, with each category assigned a unique number and only one response recorded per respondent. Responses from Likert-scale questions were coded numerically on a 5-point scale, ranging from “strongly agree” to “strongly disagree.” Data was then exported to SPSS 27 for analysis.

Data analysis

Data analysis was performed using IBM SPSS 27 and SmartPLS 4. Descriptive statistics such as frequency and percentage were used to summarize the sociodemographic characteristics of the respondents. The Kolmogorov–Smirnov and Shapiro–Wilk tests assessed the normality of data. The chi-square test and Spearman’s correlation analysis were applied to examine associations between variables, if applicable. Structural equation modeling (SEM) using the Partial Least Squares (PLS-SEM) approach was conducted to evaluate relationships among latent variables based on the Health Belief Model. The PLS-SEM analysis consisted of 2 components: (i) measurement model and (ii) structural model. Modelling of these components was similar to the procedure described in our previous studies [42, 48]. In brief, the measurement model was assessed in terms of: (i) indicator reliability, (ii) internal consistency reliability, (iii) convergent validity, and (iv) discriminant validity.

Multicollinearity among health belief model constructs was assessed using the variance inflation factor (VIF), with values < 5 considered acceptable [49]. The strength and significance of relationships were assessed using standardized path coefficients (β). Path coefficients were considered statistically significant at p < 0.05 [50]. The coefficient of determination (R²) was used to assess the model fit. Effect sizes (f²) were used to assess the magnitude of the effect of each predictor variable on the outcome. Predictive relevance (Q²) of the model was assessed using the blindfolding analysis.

Results and discussion

Socio-demographic characteristics of respondents

This study included a total of 298 respondents. Most of them were female (68.8%) and married (74.8%). Over one-third of the respondents (36.2%) had a bachelor’s degree or higher, while 4.4% were without formal education. Table 1 shows the distribution of respondents’ age, income, occupation, and their family size.

Table 1.

Socio-demographic characteristics of respondents (N = 298). NPR = Nepalese Rupees, 1 USD = 150 NPR approximately

Variables	Categories	Frequency	Percentage (%)
(i) Gender
	Male	93	31.21
	Female	205	68.79
(ii) Marital status
	Married	223	74.83
	Unmarried	60	20.13
	Divorced	7	2.35
	Widowed	8	2.68
(iii) Educational status
	No formal education	13	4.36
	Primary	43	14.43
	Secondary	46	15.44
	Higher Secondary	88	29.53
	Bachelor or above	108	36.24
(iv) Age
	< 25	39	13.09
	26–35	89	29.87
	36–45	97	32.55
	46–55	55	18.46
	> 56	18	6.04
(v) Occupation
	Student	21	7.05
	Government job	3	1.01
	Homemaker	84	28.19
	Business	70	23.49
	Health worker	4	1.34
	Private Sector	37	12.42
	Unemployed	17	5.70
	More than one	27	9.06
	Other	35	11.74
(vi) Monthly income
	No income	130	43.62
	< 10,000	24	8.05
	10,000–20,000	73	24.5
	20,001–40,000	57	19.13
	> 40,000	14	4.7
(vii) No. of family members
	2 to 4	118	39.6
	4 to 6	150	50.34
	6 to 8	27	9.06
	8 to 10	3	1.01

Structural equation modeling analysis

Structural equation modeling (SEM) analysis consisted of the 2 components: (i) measurement model, also called outer model) and (ii) structural model, also called inner model. The reliability and convergent validity of the HBM model were assessed using Cronbach’s alpha (α), composite reliability (CR; rho_A), and average variance extracted (AVE) (Table 2).

Table 2.

The reliability and convergent validity of HBM constructs

HBM constructs	No. of items	Cronbach’s alpha	Composite reliability (rho_a)	Average variance extracted (AVE)
BA	3	0.775	0.842	0.668
CA	5	0.822	0.822	0.584
PB	6	0.893	0.900	0.655
PS	6	0.864	0.884	0.594
PV	6	0.913	0.918	0.696
SE	6	0.926	0.937	0.732

BA Perceived barriers, CA Cues to action, PB Perceived benefits, PS Perceived susceptibility, PV Perceived severity, and SE Perceived self-efficacy

The alpha values ranged from 0.775 to 0.926, and composite reliability (rho_A) values ranged from 0.822 to 0.937, both exceeding the threshold of 0.70, indicating a good internal consistency. The AVE values ranged from 0.584 to 0.732, exceeding the threshold of 0.50, indicating an adequate convergent validity (Table 2).

Discriminant validity of the HBM constructs was assessed using the heterotrait–monotrait ratio of correlations (HTMT) (Table 3). The HTMT values ranged from 0.121 to 0.664, which are below the threshold of 0.85, confirming that the constructs are robust and suitable for structural modeling.

Table 3.

Heterotrait-Monotrait ration (HTMT) discriminant validity of HBM constructs

HBM constructs	BA	CA	PB	PS	PV	SE
BA	1
CA	0.231	1
PB	0.427	0.413	1
PS	0.321	0.351	0.664	1
PV	0.121	0.431	0.610	0.661	1
SE	0.160	0.576	0.497	0.513	0.529	1

BA Perceived barriers, CA Cues to action, PB Perceived benefits, PS Perceived susceptibility, PV Perceived severity, and SE Perceived self-efficacy

The structural equation model was assessed to examine the direct effects of HBM constructs, namely BA, PB, PS, PV, and SE on CA (Fig. 2). Among these constructs, SE demonstrated the strongest positive effect on CA (β = 0.184), indicating that individuals with higher confidence in their ability to manage unused and expired PPCPs are greater responsiveness to safe disposal behaviors.

Fig. 2.

Structural equation model illustrating the relationships between Health Belief Model constructs and Cues to action, values represent standardized path coefficients and indicator loadings. Notation: BA= Perceived barriers, CA= Cues to action, PB= Perceived benefits, PS= Perceived susceptibility, PV= Perceived severity, and SE= Perceived self-efficacy

Correlation between HBM Constructs

Table 4 shows the Spearman rank correlation coefficients among HBM constructs. Cues to action (CA) were positively correlated with perceived benefits (PB) (r = 0.362), perceived susceptibility (PS) (r = 0.317), perceived severity (PV) (r = 0.370), and self-efficacy (SE) (r = 0.540), and negatively correlated with perceived barriers (BA) (r = − 0.195) (all p < 0.01). BA showed significant negative correlations with PB (r = − 0.393), PS (r = − 0.229), and SE (r = − 0.193) (p < 0.01). PB were positively associated with PS (r = 0.525), PV (r = 0.489), SE (r = 0.453), while PS was strongly correlated with PV (r = 0.591). All reported correlations were statistically significant at the 0.01 level.

Table 4.

Spearman correlation coefficient between HBM constructs

Variables	BA	CA	PB	PS	PV	SE
BA	1
CA	− 0.195**	1
PB	− 0.393**	0.362**	1
PS	− 0.229**	0.317**	0.525**	1
PV	-0.106	0.370**	0.489**	0.591**	1
SE	− 0.193**	0.540**	0.453**	0.444**	0.425**	1

BA Perceived barriers, CA Cues to action, PB Perceived benefits, PS Perceived susceptibility, PV Perceived severity, and SE Perceived self-efficacy

** means correlation is significant at the 0.01 level (2-tailed)

These findings reveal meaningful interrelationships among HBM constructs. Perceived barriers (BA) were negatively associated with cues to action (CA), perceived benefits (PB), perceived susceptibility (PS), and self-efficacy (SE), indicating that individuals who perceive greater barriers are less likely to recognize cues to action, perceive benefits, feel susceptible, or have confidence in their ability to adopt safe disposal behaviors. These findings are consistent with our previous research suggesting that PB often act as a crucial determinant of pesticide safety behavior, as higher PB tend to discourage engagement in adhering safety measures [32]. Although few studies have examined correlations among HBM constructs in Nepal, limited evidence exists in the context of pharmaceutical disposal practices in S-Asia, highlighting the contribution of this study globally.

Use and storage of unused and expired PPCPs

Table 5 shows the percentage of individuals using and storing pharmaceuticals and personal care products. The findings indicate that 41.6% of households stored unused or expired PPCPs, which is lower than reports from Ethiopia (62.4%), Kabul (95%), and Ghana (68%) [19, 22, 25], but higher than that reported in Turkey (28.0%) [46]. In this study, 67.1% of respondents checked the expiry date of PPCPs before purchase, which was lower than in Indonesia (72.8%) and Kabul (97%) [20, 25], but higher than a study conducted in other regions of Nepal (45%) [51].

Table 5.

Use and storage of unused and expired PPCPs

Variables	Categories	Frequency	Percent (%)
(i) Regularly use pharmaceuticals	Yes	124	41.6
	No	174	58.4
(ii) Regularly use personal care products	Yes	218	73.2
	No	80	26.8
(iii) Purchase PPCPs at home	Self	194	65.1
	Spouse	59.0	19.8
	Others	45	15.1
(iv) Check expiry date of PPCPs before purchasing	Yes	200	67.1
	No	98	32.9
(v) Unused/expired PPCPs available at home	Yes	124	41.6
	No	174	58.4
(vi) Often check expiry date of PPCPs before using them	Always	7	2.3
	Sometimes	94	31.5
	Rarely	132	44.3
	Never	65	21.8
(vii) Manage unused/expired PPCPs at home	Self	164	55
	Spouse	74	24.8
	Children	1	0.3
	Others	59	19.8
(viii) Get information or advice from the pharmacy retailers	Yes	34	11.4
	No	264	88.6
(ix) Reasons for storing PPCPs at home	Leftover from previous illness	48	16.1
	Side-effects after use	42	14.1
	Over-purchased	42	14.1
	Prescription changed by doctors	16	5.4
	Forgot to use	62	20.8
	Others	1	0.3
(x) Places for storing PPCPs at home	Kitchen cabinet	28	9.4
	Bathroom shelf/cabinet	110	36.9
	Bedroom drawer	229	76.8
	Refrigerator	4	1.3
	Medicine box	84	28.2
	Others	20	6.7

Chi-square analysis revealed significant associations between use and storage practices and sociodemographic characteristics (supplementary information, Table S2). In contrast to the findings of our recent gender-based study with vegetable farmers in Nepal [41], gender in this study showed the weakest associations and negligible relationships with both the use and storage of PPCPs, indicating a greater gender equality in individual’s opportunities, social roles, and interactions in the municipality. We found that 76.8% of the respondents stored PPCPs in bedroom drawers, a finding consistent with studies from Turkey and Ethiopia [52, 53]. However, storing PPCPs in such places may increase the risk of accidental ingestion by children and pose serious health hazards. Table 5 reflects the main reasons for storing the unused and expired PPCPs. Similar patterns of pharmaceuticals discontinuation have been reported in studies conducted elsewhere [22, 54]. Additionally, improper storage and disposal of PPCPs may cause environmental contamination, as highlighted in previous studies [22, 39, 53].

Furthermore, age, education, occupation, and family size showed significant associations with most variables, including regular use, purchasing practices, expiry date checking, and management of unused or expired PPCPs (p < 0.05, φc = 0.145–0.644). Marital status and income were significant for selected behaviors, with income also influencing reasons for storing PPCPs, a finding consistent with a past study from Pakistan [27].

Storage locations for PPCPs were bathroom cabinets, medicine boxes, and refrigerators; all were influenced by demographic statistics. Consistent with findings from a study conducted in other regions of Nepal [51], education was significantly associated with checking expiry dates and seeking information on proper storage and handling, highlighting the significance of education in promoting safe pharmaceutical disposal practices.

Disposal practices of unused and expired PPCPs

Table 6 presents respondents’ disposal practices regarding PPCPs. Most respondents disposed of unused and expired PPCPs in household garbage (88.9%), followed by open-space burning (12.8%). These behaviors were driven by convenience (88.9%) and a lack of awareness of alternative disposal methods (58.4%). In general, unused PPCPs were commonly stored for future use (67.1%) or shared with family or friends (57.4%). Nearly all respondents (95.0%) reported mixing unused and expired PPCPs with other household waste before disposal, indicating improper disposal behavior that poses risks for environmental deterioration and public health.

Table 6.

Disposal practices of unused and expired PPCPs

Variables	Categories	Frequency	Percent (%)
(i) Dispose of expired PPCPs	Throw in household garbage	265	88.9
	Flush in toilet/sink	6	2
	Burn them	38	12.8
	Return to pharmacy retailers	4	1.3
	Give away to relatives/friends	3	1
	Stored for future use	2	0.7
	Bury underground	4	1.3
	Dispose in river/water bodies	6	2
(ii) Manage unused PPCPs	Dispose in household garbage	131	44
	Flush down toilet/sink	4	1.3
	Burn them	8	2.7
	Return to pharmacy retailers	43	14.4
	Gave them to relatives/friends	171	57.4
	Stored for future use	200	67.1
	Bury in ground	6	2
	Donate to hospital	2	0.7
	Dispose in rivers/water bodies	2	0.7
(iii) Why do you dispose in this way?	It is the easiest method	265	88.9
	I don’t know any other alternatives	174	58.4
	I believe it is a safe method	14	4.7
	I don’t think it harms environment	24	8.1
	I was advised to dispose this way	2	0.7
(iv) Mix unused/expired PPCPs	Yes	283	95
	No	15	5
(v) How frequently dispose of unused/expired PPCPs?	Monthly	6	2
	Quarterly	98	32.9
	Yearly	189	63.4
	Never	5	1.7
(vi) Have you ever returned expired/unused PPCP?	Yes	14	4.7
	No	284	95.3
(vii) If you have return to PH/health center? (Once)	Yes	10	3.4
	No	288	96.6

The analysis of disposal and management practices revealed several significant associations with sociodemographic features (supplementary information, Table S3). Improper disposal behaviors such as burning, discarding in domestic waste, burying, or disposing into water resources, were more prevalent among specific communities. Our findings indicate that majority of the respondents disposed of expired PPCPs in domestic waste (88.9%), mainly because it was easy for them and were unaware of safer alternatives. Similar behaviors have been reported in Afghanistan (77.7%), Ethiopia (53.2%), India (82.1%), and Qatar (76%) [22, 25, 39, 40]. In this study, very few respondents returned unused PPCPs to pharmacies, which might be due to the absence of formal take-back systems in the country. However, majority of individuals in the EU returned their unused medicines to pharmacies due to their high level of awareness on environmental impacts of pharmaceuticals [55]. The fact that 95% of households mixed PPCPs with domestic waste reflects low level of awareness on proper waste segregation and its environmental and health impacts. Improper disposal of unused pharmaceuticals poses serious threat to public health and the environment, including the development of antibiotic-resistant bacteria [23]. All these findings indicate a lack of clear guidance and significant gaps in knowledge and behavior regarding disposal methods of unused and expired PPCPs .

Disposal practices were significantly associated with sociodemographic characteristics (weak to moderate effect), aligning with findings from Ethiopia and Nigeria [56, 57]. Disposal of expired PPCPs in domestic waste showed significant associations with all sociodemographic characteristics except family size, with the strongest relationships observed for occupation (φc = 0.444), monthly income (φc = 0.292), and marital status (φc = 0.286). This might be due to the fact that family size affects the quantity and volume of wastes generated, but not necessarily the method of PPCPs disposal practices. Contrarily, occupation, income and marital status are related to information, resources, and social beliefs, henceforth, increasing individual’s relationship with the current disposal behaviors.

Most of the demographic features influenced the overall management of unused PPCPs, behaviors such as storing for future use and donating to hospitals showed no significant links. Mixing PPCPs with domestic waste was linked with marital status and occupation, whereas disposal frequency was linked by education, occupation, and family size. Similarly, individuals’ behavior of returning PPCPs to pharmacies was significantly linked only with marital status. Overall, our findings indicated that inappropriate disposal of PPCPs remains widespread and is strongly influenced by sociodemographic features, underscoring the need for government-level interventions to promote safe and environmentally responsible disposal practices thereby contributing to the UN Sustainable Development Goals (SDG 3).

Types of unused or expired PPCPs in households

Figure 3 and Table S4 illustrate the common types of unused or expired pharmaceuticals that were found during survey. Of all, analgesics were the most commonly reported pharmaceutical that accounted 63.1% of the total. This was followed by antibiotics and proton pump inhibitors that accounted 19.5% and 16.4%, respectively. Additionally, 31.5% of the individuals reported using other pharmaceuticals, including nasal decongestants, ophthalmic medications, cough suppressants, antidepressants, antihistamines, and lipid-lowering agents.

Fig. 3.

Types of pharmaceuticals and their percentage of usage among households

Regarding personal care products, skincare items were the most commonly reported unused or expired products (77.5%), followed by haircare products (54.7%). Perfumes, makeup products, soap/shower gels, and oral care products were less commonly reported (Fig. 4 and Table S5).

Fig. 4.

Types of personal care products and their percentage of usage among households

In brief, our findings indicate that analgesics were the most commonly stored pharmaceuticals (63.1%). This percentage is slightly lower than that reported from India (68.8%) but higher than findings from Ethiopia (32.2%), and the USA (15%) [22, 26, 58]. The percentage of antibiotics in this study (19.5%) is comparable to findings from Ethiopia (16%), lower than those reported from Afghanistan (46.5%), Saudi Arabia (48.7%), and Ethiopia (24%), but higher than those reported from the USA (6.7%) and India (8.5%) [21, 22, 25, 39, 58, 59]. The frequent storage of analgesics and antibiotics in households may be due to: (i) widespread availability, (ii) frequent use for common health problems such as pain and fever, and (iii) self-medication.

Knowledge, practices, and challenges of Pharmacy Retailers (PRs)

In this study, 53 PRs participated. Most of them were aged 26–45 years (88.7%), with females accounting for 64.2% and married individuals comprising 86.8% of the sample. Table 7 presents their demography, storage practices, awareness, and challenges related to PPCPs. Major challenges identified included the lack of a return or take-back system (37.8%), limited access to incineration facilities (24.5%), and the high cost of appropriate disposal methods (24.5%). Other challenges included limited awareness of health and the environmental impacts (9.4%) and the absence of accessible designated disposal points (9.4%). Similar findings were observed among PRs in Palestine [60].

Table 7.

Demographic characteristics, storage practices, awareness, and challenges related to PPCPs among pharmacy retailers

Variables	Categories	Frequency	Percent (%)
(i) Age group	< 25	3	5.7
	26–35	24	45.3
	36–45	23	43.4
	46–55	2	3.8
	> 56	1	1.9
(ii) Gender	Male	19	35.8
	Female	34	64.2
(iii) Marital status	Married	46	86.8
	Unmarried	7	13.2
(iv) Education	Primary	1	1.9
	Secondary	4	7.5
	Higher Secondary	20	37.7
	Bachelor or above	28	52.8
(v) How do you store PPCPs?	Store at shelves at room temperature	30	56.6
	Store at refrigerator	13	24.5
	Store at separate storage container	13	24.5
(vi) Do you ever come across expired or damaged PPCPs?	Yes	39	73.6
	No	14	26.4
(vii) Are you aware of any specific regulations or guidelines for safe pharmaceuticals disposal?	Yes	9	17
	No	44	83
(viii) What challenges do you face regarding PPCPs disposal and management?	Lack of return or takeback system from suppliers	20	37.8
	Lack of awareness about environment and health impact	5	9.4
	Lack of access to an incineration or disposal facility	13	24.5
	Lack of support system from local government	12	22.6
	Lack of reasonable cost of proper disposal methods	13	24.5
	Lack of accessible designated disposal points	5	9.4
(ix) Do you think improper disposal of pharmaceuticals harm environmental health?	Yes	32	60.4
	No	21	39.6
(x) Do you think improper disposal of pharmaceuticals harm human health?	Yes	49	92.5
	No	4	7.5
(xi) Do you provide information or advice to customers about proper disposal of pharmaceuticals?	Sometimes	17	32.1
	Often	16	30.2
	Always	20	37.7

Most PRs (92.5%) believed that improper disposal of pharmaceuticals could harm human health, while 60.4% recognized its potential environmental consequences such as: (i) water pollution, (ii) land degradation, (iii) harm to aquatic and terrestrial life, (iv) air pollution, and (v) adverse effects flora and fauna. Health-related risks identified included allergies, chemical poisoning in children, gastrointestinal diseases, and other health problems.

In terms of practice, 37.7% of PRs reported always providing guidance to their customers on proper disposal methods while 32.1% reported doing so sometimes. Our findings indicate that only a very small proportion (17%) of PRs were aware of proper disposal guidelines, and most reported returning expired or damaged products to their suppliers. These findings are in line with a study conducted in other regions of Nepal [28], indicating a significant knowledge gap. However, a recent study conducted in Nepal found a higher proportion of PRs adhering proper disposal practices for the management of unused and expired PPCPs [47]. PRs play a crucial role in educating the public about proper disposal methods to minimize adverse effects [19]. Most PRs recommended increasing public awareness, encouraging patients to check manufacture and expiry dates before purchasing, and establishing separate disposal facilities at the ward level for effective management of PPCPs waste.

Limitations

• (i)This study was conducted in selected wards of Tokha municipality, limiting the generalizability of the findings to other regions of Nepal.
• (ii)Some pharmacies were closed during the survey period, resulting in the underrepresentation of certain practices.
• (iii)Although both recall methods viz. 24-hour and 3–6-month were used, PRs may have provided socially acceptable responses rather than reflecting their actual practices.
• (iv)Data were collected in September, and seasonal variations in PPCP usage and disposal behaviors were not prioritized. Despite these limitations, this study provides valuable insights into the management of PPCPs at both: household and pharmacy levels.

Conclusion and recommendations

To the best of our knowledge, this is the first study that examined the disposal practices of unused and expired PPCPs using the HBM. Sociodemographic factors, including age, education, occupation, and family size, were found to significantly influence PPCP use, storage, and disposal behaviors. An individuals’ education positively affected the perceived severity and self-efficacy, indicating that high levels of education is likely to decrease perceived barriers for safe disposal practices. Both household individuals and pharmacy retailers face significant challenges in managing unused and expired PPCPs, contributing to the adverse effects on humans and the environment. Their waste disposal practice was not satisfactory due to perceived barriers such as both groups lack access to take-back systems and convenient disposal facilities. Additionally, unfamiliarity with rules and regulations related the improper disposal of unused and expired PPCPs was also a barrier for retailers. Of all, analgesics and skincare products were the most frequently reported expired and unused items.

To address the aforementioned challenges, following interventions are recommended.

• (i)Raise perceived severity through community-based awareness programs focusing on health and environmental risks.
• (ii)Build self-confident by providing accessible disposal facilities and designated collection or take-back points at pharmacies, health centers, or municipal offices.
• (iii)Strengthen cues to action via development and enforcement of clear regulatory frameworks that are necessary for the sustainable management of unused and expired PPCPs.

Authors’ contributions

**Govinda Bhandari** : Conceptualization, Methodology, Software, Validation, Investigation, Resources, Writing-original draft. **Urmila Gharti Magar** : Conceptualization, Methodology, Software, Validation, Formal analysis, Data Curation, Visualization, Writing-original draft.

Funding

No funding.

Data availability

Data and information available from the corresponding author upon reasonable request.

Declarations

Ethics approval and consent to participate

Before the research begins, the formal ethical approval was obtained from the research ethics committee of the Progressive Sustainable Developers Nepal (approval number: 014/081/082). Study procedures were conducted in accordance with the Declaration of Helsinki. Verbal informed consent was obtained from all participants after clearly explaining the objectives of the study. Participation was voluntary and confidentiality of all respondents were strictly maintained.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.